If you read our latest blog then you will understand the important role the cardiovascular system has on maintaining homeostasis, and more. With many breeds predisposed to health issues, it pays to consider if there are dietary compounds which can support heart health. Here at My Pet Nutritionist, it’s something we deal with regularly, so we thought we’d put together our top nutrients for heart and cardiovascular health. Magnesium Taurate One of the most abundant minerals in the body, along with calcium and phosphorus, magnesium is essential to bodily function. Whilst there is some disagreement on the numbers, anywhere from 60-70% of the body’s magnesium is found in bone; the rest is in cellular fluid and soft tissue. Magnesium deficiencies have been linked with cardiovascular disorders, including high blood pressure and abnormal rhythms and there are a number of mechanisms in which magnesium supports heart health and function. Magnesium naturally competes with calcium which is essential in generating heart muscle contractions. Calcium stimulates the muscle and magnesium counters it which helps them to relax (this is also why magnesium is used in cases of spasms). When magnesium levels are low, calcium can overstimulate heart muscles causing a rapid or irregular heartbeat. Magnesium is thereforekey to maintaining balance. Magnesium taurate contains the amino acid taurine and it’s this combination that supports healthy blood pressure; to this end it is suggested that this form bolsters heart health. Methylated B Vitamins There are eight B vitamins: B1 Thiamin B2 Riboflavin B3 Niacin B5 Pantothenic Acid B6 Pyridoxine B7 Biotin B9 Folate B12 Cobalamin These vitamins are involved in many functions as they help a variety of enzymes do their jobs – they help release energy from macronutrients and transport oxygen and energy containing nutrients around the body. Studies have noted that suboptimal serum levels of folic acid, vitamin B12 and vitamin B6 may underlie the development of heart disease. It is suggested that such deficiencies lead to inadequate production of S-adenosyl-methionine, creating a state of hypomethylation. This, in turn, may damage the DNA in arterial cells. Methylation is a biochemical process which involves the addition of a ‘methyl group’ to other molecules and is dependent on the availability of a number of key nutrients. When these B vitamins are supplemented in their methylated form, it’s almost like it’s one less job for the body to do. Omega 3’s How Omega-3 Fatty Acids May Affect the Heart: Lower triglyceride levels, increase HDL (ie, good cholesterol) Lower resting blood pressure Decrease platelet aggregation and prevent blockage of coronary artery Decrease risk of arrhythmias (abnormal heart rhythm) Increase compliance of arteries Decrease atherosclerosis Reduce inflammatory markers There is evidence of rapid declines in coronary heart disease mortality with the consumption of oils rich in alpha-linolenic acid. Findings Here Studies have demonstrated a significant reduction in risk of sudden cardiac death in humans consuming the most linolenic acid. A diet rich in linolenic acid has been associated with a lower incidence of calcified coronary plaques along with a reduced risk of cardiovascular mortality, which subsequently lowers the all-cause mortality levels in humans. Findings Here In Humans, the Lyon Diet Heart Study is perhaps the most well-known, and it separated 605 myocardial infarction survivors into two groups, one group was placed on a low-fat diet, and the other on a Mediterranean diet including margarine enriched in linolenic acid (1.1 g/day). After a two-year follow-up, the incidence of cardiovascular disease, including cardiac mortality, decreased dramatically (73%) in the intervention group. This raised the possibility that the inclusion of linolenic acid in the diet can significantly improve cardiovascular health. Evidence has suggested that omega-3 supplementation has reduced the incidence of atrial fibrillation in dogs and as we know, atrial fibrillation is a heart condition that causes an irregular and abnormally fast heart rate. Findings Here There is also data which suggests omega-3 supplementation significantly affects survival rates in those dogs suffering with heart failure secondary to DCM. Findings Here It is thought that the effect of omega-3 is multifactorial, but they include significant effects on sodium, potassium, and calcium channels. It is also considered that omega-3’s reduces platelet aggregation, which mitigates risks of clots and therefore won’t impede blood flow to the heart. Findings Here COQ10 Coenzyme Q10 (CoQ10) is an essential compound of the body which is synthesized in the mitochondrial inner membrane. It has many important functions in human body. Firstly, it can be named the key-component of electron transport chain in mitochondria necessary for ATP production and secondly, in addition to its important role in electrons’ transport, COQ10 can act as an intercellular antioxidant, protecting the plasmatic membrane against peroxidation. Oxidative stress is considered to be an essential player in the development of cardiovascular disease, and it is this theory that suggests antioxidants’ like COQ10 can subsequently lower the risk. In the body, COQ10 is found in all systems of organs. The highest concentration of ubiquinone is noted in the tissues of the heart, kidneys, liver and muscles. In humans, three out of four patients with heart diseases have low levels of CoQ10. It was noticed that CoQ10’s plasma levels in patients with ischemic heart disease and dilated cardiomyopathy are much lower than in healthy ones. Depending on the severity of heart injury, circulating level of COQ10 decreases in direct proportion to disease progression. Furthermore, heart failure is related to a chronic pro-inflammatory state and there are increasing studies that establish anti-inflammatory properties of COQ10. CoQ10 deficiency is frequently encountered in dilated cardiomyopathy, and this may be reversible by the COQ10 administration. In a prospective, randomized, double-blinded, placebo-controlled trial in children with dilated cardiomyopathy, COQ10 administration for 6 months resulted in improvement of diastolic function and a lower mean score for the index of cardiac failure. Findings Here Hawthorn Hawthorne is widely used in Europe as a cardiotinic and for congestive heart failure. The principle active components in hawthorn leaves, berries, and blossoms are flavonoids. One of these flavonoids, proanthocyanidin, has especially important cardiovascular effects. Mechanisms
Kennel cough is a broad term covering any infectious or contagious condition of dogs where coughing is one of the main symptoms. It’s sadly a common occurrence in the dog population, so let’s take a look at what it actually is and our top tips for prevention and management. Did you know several viruses and bacteria can cause kennel cough, and often at the same time? They include (but are not limited to): Adenovirus type-2 (distinct from the adenovirus type 1 that causes infectious hepatitis), Parainfluenza virus Bordetella bronchiseptica. Canine Adenovirus Type 2 Infection CAV-2 infection is a common but transient contagious disease of the respiratory tract of dogs, it tends to cause mild fever, nasal discharge, coughing, and poor weight gain. Viral entry is generally by inhalation of infected particles followed by viral replication in the cells of the upper respiratory tract, mucous cells of the trachea and bronchi, bronchiolar epithelial cells, and others. Infection with CAV-2 is generally deemed mild unless complicated with a secondary bacterial infection or coinfections with other viruses like distemper virus. Experimental work suggests CAV-2 reinfection may lead to hyperreactive airways, which is a nonspecific condition where the bronchial mucosa becomes highly responsive to irritation caused by cold air, gases, or cigarette smoke. Canine parainfluenza virus (CPIV) This virus is a highly contagious ribonucleic acid virus that causes respiratory disease in dogs. Dogs with CPIV may exhibit no clinical signs or mild clinical signs of a dry, harsh cough for around and up to 7 days, with or without fever and nasal discharge. These signs are generally more severe in those dogs with viral or bacterial coinfections. CPIV suppresses the innate branch of the immune system, resulting in the loss of cilia and ciliated epithelium, making the host more favourable for coinfections. This is why it is of concern for immunocompromised dogs, along with puppies, or the senior dog. CPIV survives on nonporous surfaces for 4 to 12 days, but it is susceptible to a range of disinfectants. Bordetella bronchiseptica B bronchiseptica is a gram-negative, aerobic coccobacillus that is often implicated as a complicating factor in dogs with concurrent viral respiratory infections. After B bronchiseptica colonises the airways, it can evade the immune system by expressing various virulence factors that lead to: Direct cellular injury of respiratory epithelium Impaired immune recognition Disrupted immune clearance It seemingly manages to paralyze the mucociliary apparatus—a key component of the respiratory tract’s local defence mechanisms. The mucociliary apparatus moves inhaled debris and potentially harmful pathogens away from the lower respiratory tract, decreasing the risk of colonisation by these organisms. By doing this, B bronchiseptica not only improves its own virulence and chance for colonisation, but also paves the way for infections of the lower respiratory tract. In cases of infection, some dogs suffer mild disease including nasal discharge and intermittent coughing, whereas others develop severe pneumonia. Canine Infectious Respiratory Disease Complex (CIRD) The coinfection of these pathogens, among others, manifests as CIRD and they act synergistically to causes respiratory illness. This is why a multifaceted approach to prevention and subsequent management is crucial. Immune Function As you have likely noticed, CIRD is an attack on the immune system. The pathogens hijack many defences which results in the lingering symptoms. So, a well-functioning immune system is the first part of your dog’s defence against kennel cough. Vitamin C contributes to immune defence by supporting various cellular functions of both the innate and adaptive immune system. Vitamin C helps encourage the production of white blood cells known as lymphocytes and phagocytes, which as you know if you read our guide to the immune system, they help protect the body against infection. Your Pet’s Immune System Vitamin A helps maintain structural and functional integrity of mucosal cells in innate barriers (skin, respiratory tract etc). It is also important for the functioning of natural killer cells, macrophages, and neutrophils. In the adaptive immune response, vitamin A is necessary for the functioning of T and B cells and therefore for the generation of antibody responses to an antigen. Vitamin A also supports the Th2 anti-inflammatory response. In the innate immune system, vitamin B6 helps regulate inflammation and has roles in cytokine production and natural killer cell activity. In the adaptive immunity system, vitamin B6 plays a role in the metabolism of amino acids, which are the building blocks of cytokines and antibodies. B6 is also involved in lymphocyte proliferation, differentiation and maturation and it maintains Th1 immune responses. Stock or broth made by boiling chicken bones is a great option and contains gelatin, chondroitin and other nutrients that are helpful in gut healing in immune function. Zinc is a particular powerhouse when it comes to immune function. It has antioxidant effects protecting against reactive oxygen species, it helps modulate cytokine release and also helps maintain skin and mucosal membrane integrity (that first line of defence). In the adaptive immune response, zinc has a central role in cellular growth and differentiation of immune cells. It plays a role in T cell development and activation and supports the Th1 response. We find vitamin D receptors throughout the immune system which demonstrates the role it plays in its function. Vitamin D stimulates immune cell proliferation and cytokine production, and it helps protect against infection caused by pathogens. It also demonstrates an inhibitory effect in adaptive immunity, suggesting that it is in fact an immune modulator. This is often why we notice increased cases of autoimmunity where there is low vitamin D. Further to this, we often note higher rates of infection (with a range of pathogens) when there are existing health issues that involve: The gut Thyroid Kidneys Liver function 7 Steps to Optimal Gut Health Liver Health Kidney Disease Therefore, ensuring you take a holistic approach to your dog’s health is vital. But, we do have some tricks up our sleeves when it comes to dealing with kennel cough in dogs. Mushrooms Mushrooms are thought to have antimicrobial, anti-inflammatory, cardiovascular-protective, antidiabetic, hepatoprotective, and anticancer
It turns out September is Happy Cat Month. Now, if you’re like us here at My Pet Nutritionist, we sometimes get a little lost if certain appreciation days are National or International, but either way, what better time to share some of our top tips for keeping your feline friend both happy and healthy? 1) Species Appropriate Diet Cats have evolved as hunters that consume prey containing high amounts of protein, moderate amounts of fat, and minimal amounts of carbohydrates. The cat has seemingly evolved as a strict or obligate carnivore; meaning they nutrients they require are found in animal tissue. As such, the consensus is that there is no current nutritional basis for energy to be supplied by carbohydrates; providing other nutrients are being supplied. There is also evidence that there is limited amylase activity in the pancreas and small intestine (even compared to dogs), which may explain why some cats will not tolerate high starch diets. The fact that cats are also defined as hypercarnivores (small carnivorous mammal with a proportionally large brain) indicates they have a high brain glucose demand. This high demand simply could not be met by carbohydrates present in a natural prey diet; and so, cats therefore have a higher rate of gluconeogenesis (the production of glucose from non-carbohydrate sources). It is considered that due to the limited intestinal enzyme capacity, consumption of excessive amounts of digestible carbohydrates will not lead to glucose absorption, but rather a substrate for increased microbial fermentation, causing gastrointestinal adverse effects. In similar tests to dogs, cats are able to target their nutrient intake. When given the choice, they will specifically aim for a high intake of protein. In times of low protein, they will opt for an increased fat intake to achieve balance. When carbohydrate intake was high, this limited intake of other nutrients and resulted in deficits – for that reason, a carbohydrate ceiling is proposed for the cat. Findings Here 2) Limit Toxin Exposure Whenever the body is exposed to something, it must do something with it. In the case of toxic substances, it must make it less toxic, hence the word detoxification (de=remove or reverse). Detoxification pathways fall into three phases. The first two phases are concerned with breaking down the toxin in the body, and phase three is concerned with excreting it. For us to manage ours and our cat’s toxic load, all three phases need to be working optimally. Phase one is particularly nutrient demanding, and it produces a lot of reactive oxygen species in the process (those cheeky things that result in oxidative damage which destroys and damages cells). Phase two is also nutrient demanding, but drafts in many different processes depending on the compounds being detoxified. Phase three deals with getting rid of them once and for all, and occurs in the gut, skin, liver and kidneys. So, it stands to reason that optimal organ function is helpful here. The issue is that the cat is playing catch up. They aren’t as efficient at these processes as other species, like us, and when we are increasing toxin burden year on year, it becomes problematic. They have even demonstrated a total inactivation of certain genes responsible for certain phenol detoxification. So, whilst limited toxin exposure is important for us all, it’s even more important for our cats. Where possible, limit exposure to: Plastics Mould Smoke Air pollution Heavy metals VOCs – air fresheners, cleaning products, fabric softeners The Struggle of The Cat in Our Toxic World Is Your Toxic Home Affecting Your Pet 3) Offer Fresh Filtered Water Cats don’t naturally have a thirst drive, they evolved to survive in hot, desert climates. But when they have access to their natural diet, a large percentage of that would contain moisture. Dry food increases thirst behaviour: this is demonstrated in dog studies time and time again, but there is still a mismatch between the cat’s evolutionary thirst (or lack thereof) and the moisture in their diet. Water is possibly the single most important nutrient for the body. 1) It functions as a solvent that facilitates reactions and also transports nutrients around the body. 2) Water is able to absorb heat from the processes occurring in the body, without the overall body temperature changing too much. 3) It further contributes to temperature regulation by transporting heat away from working organs through the blood. 4) Water is crucial in the digestive process; it is a key player in hydrolysis, which is the splitting of larger molecules into smaller molecules (through the addition of water). 5) The kidneys also use large quantities of water when eliminating waste. A high moisture diet is beneficial to the cat to ensure they are hydrated, but fresh filtered water should also be offered. As in point two, toxin exposure should be limited and even in the most developed countries there is contamination. Chlorine, heavy metals, plastic fibres and pharmaceutical compounds are regularly found in tested tap water, which all pose risks to our feline friends. The Importance of Water 4) Let them Hide! Cats get stressed. There is no denying that. But they are often a little more subtle in their anxieties than other animals. As in humans, cats will have the same response to stress. They may choose to fight, flight, or freeze. When they fight, they become aggressive and defensive. Flight will see them withdrawing from the threat and perhaps running away. When cats freeze, they crouch, lie still, and try to avoid any attention. There is a ladder of response in most animals, and this is no different in cats. They will often show subtle signs of discomfort or stress. If the trigger doesn’t disappear, the behaviours will progress. You may start with the flat ears, then the pupils will dilate. You may have a low growl or a silent hiss. Them running off or lashing out with their teeth and claws may be a few steps up the ladder. For some cats, there are triggers
As we know bacteria is everywhere, both the good ones and the not so good ones. Sometimes the bad ones can get a little out of hand and start causing a whole host of problems, we know this as bacterial overgrowth and we’re going to be looking at small intestinal bacterial overgrowth, or SIBO specifically. Here at My Pet Nutritionist is something we keep an eye out for, so we thought we’d let you know why. Small intestinal bacterial overgrowth (SIBO) is defined as excessive bacteria in the small intestine. SIBO is frequently implicated as the cause of chronic diarrhoea and malabsorption. Dogs with SIBO may suffer from unintentional weight loss, nutritional deficiencies, and osteoporosis for example. When we reference the microbiome, we are considering the microbial community found in the whole of the digestive tract. Generally, the further down we go, the more bugs we find. So, we would expect the majority of the bugs to be found in the colon. SIBO is when there are higher numbers found in the small intestine. The type of microbial flora present plays an important role in the manifestation of signs and symptoms of overgrowth. For example, a predominance of bacteria that metabolize bile salts to unconjugated or insoluble compounds may lead to fat malabsorption or bile acid diarrhoea. In contrast, microorganisms that preferentially metabolize carbohydrates to short-chain fatty acids and gas may produce bloating without diarrhoea because the metabolic products can be absorbed. There are a number of contributing factors to the development of SIBO but two of the main ones are gastric acid secretion and small intestine dysmotility. Gastric Acid Gastric acid is necessary in the digestion of food. Not only that but it suppresses the growth of ingested bacteria (it forms one of the protective barriers), which limits bacterial counts in the upper small intestine. Gastric acid is produced in the stomach, so it provides a buffer before compounds even reach the small intestine. Gastric acid is produced by the parietal cells in the stomach, and there are cases of autoimmunity whereby the body attacks its own parietal cells resulting in low levels of gastric acid. Not only that but certain medications like proton pump inhibitors are also used to suppress gastric acid. Antihistamine medications also suppress gastric acid secretion. PPIs are often used to treat a range of GI disorders in dogs and antihistamines are regularly used to treat allergic dermatitis. In addition, gastric acid secretion is regulated by the parasympathetic nervous system via the vagus nerve and there is clear evidence that increased levels of certain stress hormones inhibits the release of it. Can Stress Affect My Dog’s Digestive System The stress response also plays a role in intestinal motility. Intestinal Motility Several programmed movements are responsible for the transport of food between the different parts of the digestive system. Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract. The migrating motor complex typically moves between the stomach and small intestine, sweeping the intestine clean between meals; this is the rumble you will hear! Hormones like motilin and ghrelin are involved in the generation of MMCs. Mass movement is another programmed movement, and this is what propels the formed poop into the rectum, ready for evacuation. Mass movements are put on hold overnight but start again in the morning. They follow their own circadian rhythm. Impaired gastric motility can result in food and waste sitting in the small intestine for longer that it should. There are a number of reasons why motility may be affected. Mechanical obstruction, Abnormalities in smooth muscle function, Secondary conditions such as electrolyte disturbances, metabolic disorders, concurrent medication use, stress, and abdominal inflammation. However, there is more attention being paid to the development of SIBO through antigens gaining access to the lamina propria. The lamina propria is a thin layer of connective tissue that forms part of the moist linings known as mucous membranes or mucosa which line the respiratory and gastrointestinal tract. It is therefore thought that a compromised mucosal barrier is a risk factor for SIBO. The mucus layer is the very first line of physical defence that external molecules encounter when they arrive in the gut lumen, it prevents bacteria from directly contacting the epithelial cells, along with toxic substances and digestive enzymes. Within this strand, it therefore prevents colonic inflammation. The main building blocks of the mucus layer are highly glycosylated mucin proteins that form a gel-like sieve structure overlying the intestinal epithelium. The small intestine only has one mucus gel layer whereas the colon has two layers: an outer, loose layer that allows the long-term colonisation of commensal bacteria, and an inner dense layer empty of bacteria. Mucin degradation has been recognized as a normal process of mucus turn-over in the GI tract, but selective bacterial species can degrade mucous glycans as an energy source in the absence of other food sources and so if degradation outperforms secretion, we start to have a problem. Furthermore, diets high in refined products, sugars and saturated fats are also associated with compromised mucosal function. Early stress is also linked to impaired mucosal development, so the health of our puppy’s gut really does start with the Mother! Prevalence of SIBO SIBO has also been noted in dogs with existing chronic intestinal disease, and although many breeds are affected, German Shepherds are seemingly predominant in reports. SIBO is regularly seen in dogs with exocrine pancreatic sufficiency. Juice culture is the gold standard for SIBO diagnosis, but it is often described as being technically difficult, time-consuming and expensive. In addition, bacterial counts may be influenced by environmental factors and infective load. One of the first things to consider is whether your dog is currently eating an antigenic diet – with the increased intestinal permeability that often accompanies SIBO, establishing sensitivities is a good place to start. Elimination Diets For Dogs In addition to this, if SIBO has been prolonged there may be underlying nutrient deficiencies so
One of the most controversial discussions in the pet world is the link between diet and heart health – sadly, there are a number of reasons why heart function can be compromised, including genetics. Here at My Pet Nutritionist, we don’t think you can look at a health issue without considering the normal functioning of the system, so we thought we’d explore heart health in a little more detail. Let’s get cracking. The Cardiovascular System The cardiovascular system includes the heart and blood vessels (veins and the arteries). The function of the heart is to pump blood. The right side of the heart pumps blood to the lungs, where oxygen is added to the blood and carbon dioxide is removed from it. The left side pumps blood to the rest of the body, where oxygen and nutrients are delivered to tissues, and waste products are transferred to the blood for removal by other organs (like the kidneys). The heart is a hollow, muscular organ, divided into 4 chambers. There are upper chambers on both the left and ride sides of the heart called the left and the right atria. There are also 2 lower chambers called the left and right ventricles. A series of valves keep blood flowing in one direction through the heart. Each ventricle has an inlet and outlet valve. A heartbeat is actually the sounds of different valves closing. How does a Heart Beat? The heart beats because of electrical currents. Rhythmic electrical impulses or discharges cause the contraction of muscle fibres in the heart. At rest, the discharge is around 120 times per minute in a cat and 60-120 times per minute in the dog. Heart sounds are produced by the rapid acceleration and deceleration of blood and the resulting vibrations in the heart due to the circulation of blood. In dogs, 2 heart sounds can normally be distinguished. Calcium plays important roles in the electrical activity and pumping function of the heart. Calcium particles enter the heart muscle during each heartbeat and contribute to the electrical signal. When calcium is removed, relaxation is triggered. Potassium too plays a vital role at a cellular level. It’s movement in and out of cells helps maintain a regular heartbeat. Low levels of potassium lead to irregular contractions. When there is a high level of a compound in the body, it is termed, hyper, when there are low levels of a compound in the body, it is termed hypo. Sadly, too high and too low levels of all the above can result in irregularities in heart function. Hypokalaemia – low potassium Severe hypokalaemia is likely to cause skeletal muscle weakness, cardiac arrhythmias, and electrocardiographic abnormalities. Causes: Excessive diuretic therapy Vomiting and diarrhoea Diabetes Medications – steroids Conditions including Cushing’s Syndrome and liver failure. Hyperkalaemia – high potassium In this case, cardiac arrhythmias are common. Causes: Insulin deficiency Certain medications (NSAID’s, ACE-inhibitors) Potassium containing antibiotics Hypercalcaemia – high calcium Hypercalcaemia may present as fatigue, depression, confusion, anorexia, nausea, vomiting, constipation, peptic ulceration, or pancreatitis. Cardiac arrhythmias can occur. Causes: Parathyroid related Vitamin D intoxication Hyperthyroidism Vitamin A intoxication Cancer-related Renal failure Hypocalcaemia – low calcium Cardiac arrhythmias will be noted. Causes: Decreased intake of Vitamin D Vitamin D malabsorption Parathyroid related Acute renal failure Sodium is also important for heart health. It initiates contraction in muscles, in both skeletal and cardiac. Sodium deficiency is associated with restlessness, tachycardia, polyuria, and dry and tacky mucous membranes. The current minimum requirement for sodium has been established at 13.3mg/kg bw for dogs, but a higher quantity is suggested for bitches during gestation and lactation. In addition, greyhounds and sled dogs are allocated a higher requirement based on their high levels of exercise. At present, commercially available dog foods provide sodium intakes in excess of minimum requirements. Whilst some posit that dogs are increasingly adaptable to sodium intake, a study carried out in 2003 identified 82 dogs with dilated cardiomyopathy. They established that those with congestive heart failure ate significantly more sodium than those dogs without congestive heart failure. It pays to note that 25% of total daily sodium intake came from treats and table scraps, however. Findings Here Heart Murmurs Heart murmurs are vibrations that can be heard coming from the heart or major blood vessels and generally are the result of turbulent blood flow or vibrations of heart structures, such as part of a valve. Murmurs are typically described by their timing, their intensity, and their location. Not every murmur indicates a heart disorder, however. A heart murmur is like when you hit some white water on a usually calm river. Congenital Murmurs and Acquired Murmurs Congenital murmurs are associated with heart defects that the pet was born with. However, sometimes the defect is only detected later in life. An acquired murmur is a murmur that a pet acquires during their life. These can be benign, but more often (especially in dogs) are associated with developing heart disease. Heart Disease causing Murmurs Mitral valve disease (MVD) is a common acquired heart disease accounting for about 75% of cardiac disease seen in dogs in general practice. Prevalence of MVD increases with age and can be seen in high-risk breeds such as the Cavalier King Charles Spaniel. It is most common in small-medium sized breed dogs. Dilated cardiomyopathy (DCM) is the other main acquired heart disease seen in dogs. It can be primary in origin or secondary to dietary deficiencies or doxorubicin toxicity (chemotherapy medication). DCM has been reported in Dobermans and Golden Retrievers but other large or giant breed dogs have also been described. DCM is characterised by ventricular dilatation and systolic dysfunction. This poor systolic function means that a heart murmur is often low grade in its intensity. As DCM is regularly considered an inherited condition, it has been posited that certain breeds may need higher concentrations of amino acids like taurine and l-carnitine. Taurine and Heart Healt Taurine is the most abundant intracellular sulphur-containing amino acid. Although it can be
Here at My Pet Nutritionist we often deal with dogs who have either a congenital or acquired liver shunt. There is often some misunderstanding around liver shunts because in medicine there are procedures where a “shunt” is inserted into the brain to drain excess spinal fluid – but a liver shunt is a little different, so let’s take a look at what they are and considerations to make in any treatment plan. Liver Function The liver processes blood and the substances found within it. In a healthy animal, blood draining from the intestines passes immediately through the liver for nutrients to processed and for toxic compounds to be removed. The blood then re-enters main circulation. But in an animal with a portosystemic shunt (liver shunt), a significant volume of blood bypasses the liver, enters main circulation and heads to the heart where it can be pumped around the body. As the blood being pumped around the body is technically unfiltered, toxic compounds can build up. In addition, the liver is unable to break down nutrients or regulate the body’s energy balance. In most cases, a liver shunt is caused by a birth defect. This is known as a congenital portosystemic shunt. But acquired shunts can also occur – this is usually linked to primary liver disease, or a disease involving the normal blood vessels into the liver. Symptoms of a Liver Shunt: Stunted growth Poor muscle development Abnormal neurological behaviour – disorientation, staring into space, circling or head pressing, seizures Drinking/urinating too much Vomiting Diarrhoea Lethargy In addition, if a shunt is secondary to liver disease, then you would also note additional symptoms associated with poor liver function including: Loss of appetite Jaundice Fluid retention Liver Guard Congenital Liver Shunts In this instance, your puppy will be born with their shunt. At present there are 33 breeds that are significantly more likely to have a liver shunt than the general population. They include: Havanese Yorkshire Terrier Maltese Pug Miniature Schnauzer Standard Schnauzer Shih Tzu Bernese Mountain Dog Bichon Frise Irish Wolfhound Old English Sheepdog Of interest however, is that in Yorkshire Terriers, the incidence of shunts has increased more than 11 times in the past two decades. In addition, when mating two surgically corrected Yorkshire Terriers, they produce normal offspring. This poses questions around simple autosomal recessive inheritance. Findings Here When the foetus is developing, they will have a large shunt known as the ductus venosus; this carries blood quickly through the foetal liver to the heart. A congenital shunt develops if the ductus venosus fails to collapse at birth and remains intact and open after the foetus no longer needs it, or if a blood vessel outside of the liver develops abnormally and subsequently remains open after the ductus venosus closes. Small breeds tend to suffer extrahepatic liver shunts, which are just one abnormal blood vessel outside of the liver. These are most amenable to surgical correction. A single shunt located inside of the liver is more common in larger breeds and known as intrahepatic – these are still best treated with surgery, but the procedure is more challenging. Surgery for liver shunts focuses on blocking the blood flow through the abnormal vessels so that more of it travels through the liver. Dogs with acquired shunts on the other hand, tend to have multiple abnormal vessels and are often poor candidates for surgery due to their underlying health issues. Acquired Liver Shunts In cases of liver disease, blood flow can become compromised leading to what is known as portal hypertension – or simply, high blood pressure. Like water, blood likes to take the path of least resistance and so APSS (acquired portosystemic shunts) are formed. Clinical parameters would indicate underlying hepatic concerns. In both cases of congenital and acquired, reduced blood flow to the liver also results in atrophy which subsequently affects function. But the liver is a rather unique organ, it is the only one that can regenerate, therefore appropriate intervention and management is essential. Liver Guard Considerations To Make The most common treatment regime (in addition to surgery if appropriate) usually includes a diet change and ensuring intestinal health. The conventional concern with many liver issues is protein intake. When protein is broken down in the body, left behind is ammonia. The liver plays a key role in metabolising ammonia ready for it to be excreted by the kidneys into urine, but when blood flow bypasses the liver, ammonia builds up in the blood and enters systemic circulation – this is what leads to many neurological issues alongside poor liver function. Traditionally, dietary management has included protein restriction to reduce ammonia absorption from the colon, but more recently it is considered that colonic absorption is only significant in those fed poor-quality diets, that contain poorly digestible protein. In addition, it has been established that those with chronic liver disease may develop muscle wasting from being in a long-term catabolic state – with low protein diets leading to increased muscle protein catabolism. Findings Here Therefore we would advocate a fresh-food diet, with highly digestible protein sources. The general school of thought is 2g of protein per kg of body weight. Findings Here Antibiotics are often prescribed in an attempt to reduce intestinal bacterial overgrowth, but there are other considerations to make with regards to intestinal health. Motility – if food sits too long in any one place, problems can start to occur. Stress is one of the key factors which impair motility, so consider your dog’s exposure to any stressful stimuli. In addition, fibre can aid intestinal transit. 5 Reason’s Why Fibre is Your Dog’s Best Friend There are additional factors that can skew the microbial population in your dog’s gut too. What Can Cause Gut Dysbiosis What Can Help Gut Dysbiosis Whilst the liver is unable to effectively metabolise and detoxify, it is important to support this process as much as possible, starting with not overloading it in the first place. Opt for filtered water Feed
Sadly, here at My Pet Nutritionist this is a condition that we are seeing more and more, so we thought we’d pop a blog together to explore, what it is, common causes and considerations to make. So, let’s get cracking. What is Cushing’s Disease? Cushing’s disease in dogs, also known as hyperadrenocorticism, is a condition where a dog’s body produces too much of the stress hormone cortisol. Hyper meaning too much, adreno meaning the adrenal gland and corticism refers to the outer part, or cortex of the adrenal gland. Cushing’s in dogs is the opposite to Addison’s disease, which is when the body doesn’t produce enough hormones. That’s a blog for another day. Both decreased and excessive production of this hormone can be life threatening. The role of Cortisol We tend to know about cortisol as the common stress hormone – but it tends to get a bad rap. Cortisol doesn’t cause stress, it’s just what is produced in response to it. Cortisol is a glucocorticoid (steroid hormone) that is produced from cholesterol in the adrenal glands located on top of each kidney. It is normally released in response to waking up, exercise and of course during stress. But cortisol also plays a role in nutrition. It is involved in energy regulation as it helps select the right type and amount of substrate (like fat or protein) the body needs to meet the physiological demands it is under. When chronically elevated it can have deleterious effects on weight, immune function, and subsequent chronic disease. One of the main functions of cortisol is to reduce inflammation in the body – which is great, but over time these efforts suppress immune function. Chronically elevated cortisol can lead to immune dysfunction which paves the way for sensitivities, and it also increases the risk of gastrointestinal issues. As you can see cortisol has wide ranging functions throughout the body, so it’s easy to see how Cushing’s Disease may not always be diagnosed straight away. Symptoms Include: Increased hunger Increased thirst Frequent urination Hair loss Slow hair regrowth Abdominal swelling (pot belly) Thinning skin or lesions Lethargy Excessive panting Skin Infections. Causes of Cushing’s Disease in Dogs Pituitary Gland Tumou The most common cause of Cushing’s disease is a tumour of the pituitary gland (which is located at the base of the brain). The tumour may be either benign (harmless) or malignant (cancerous). The tumour causes the pituitary gland to overproduce a hormone (ACTH) that stimulates the adrenal glands to produce cortisol. You’ll also remember ACTH for it’s role in the stress response. As the pituitary gland produces more ACTH, it triggers the adrenal glands to produce more cortisol. Adrenal Gland Tumour Cushing’s disease may be the result of a benign or malignant tumour of the adrenal gland itself (adenoma or carcinoma, respectively). If the tumour is benign, surgical removal is considered. Excessive Cortisol from Prolonged Use of Steroids The third type of the disease is called Exogenous Cushing’s Disease. It is caused when there is excessive administration of an oral or injectable steroid. Although the steroids may have been given for a legitimate medical reason, in this case, their excess has become harmful. Glucocorticoids (GCs) are a group of drugs structurally and pharmacologically similar to the hormone cortisol with various functions including anti-inflammatory, immunosuppressive, anti-proliferative, and vaso-constrictive effects. They are often used as replacement therapy in cases of Addison’s Disease, but also as symptomatic treatment in cases of: Allergies Asthma Sickness/nausea Autoimmunity Chronic inflammatory disease like IBD Steroid-responsive dermatoses Arthritis Preterm delivery They are liked because as in cortisol’s natural role, glucocorticoids lead to suppression of the immune system and decreased inflammation. But the downstream effects of glucocorticoids include: Decreased cytokine production Decreased phagocytosis Decreased number of lymphocytes, macrophages, monocytes, eosinophils, and basophils (all immune cells) And of course, the exogenous administration can lead to Cushing’s Disease. In these cases, collaboration with a qualified professional will establish whether steroid usage can be reduced safely. As noted, the most common cause of Cushing’s Disease is a tumour in the pituitary -so where does this come from? Tumours Generally, the first step to cells becoming cancerous is unusual DNA (deoxyribonucleic acid) structure. DNA contains the instructions that us and our pets need to develop, live, and reproduce. These instructions are found in every cell and are passed down from parents to their offspring. Every cell must undergo growth, and then it must die. Each cell has a finite number of times it can reproduce, which is why we age. Cancer cells on the other hand, do not – they grow, the body is unable to kill them and so they continue to grow. DNA was largely considered destiny for many years and although DNA cannot be altered, it’s expression can. When our pets are born, they may have been given rogue genes that could cause cancer to grow, but their environment and lifestyle choices can help make that decision too. These choices can make cancer cells grow, or equally, prevent them from dying. Nutrition is, not surprisingly one of those choices to consider. The nutrients required for DNA replication include folate, vitamin B12, magnesium, zinc and iron. For the maintenance of DNA methylation and chromosome stability, the nutrients folate, vitamin B12 are of particular importance. To prevent DNA oxidation, provision of vitamin C, vitamin E, zinc, manganese, and selenium is necessary. For DNA damage sensing and repair, niacin, zinc, iron and magnesium are critical. Evidence suggests that deficiency in these micronutrients can increase DNA replication stress and genomic instability. In addition, deficiency here is thought to increase susceptibility to DNA damage caused by endogenous and/or environmental toxins. The bottom line? Certain changes in DNA can cause pituitary cells to produce a tumour – these changes can be inherited but they can also be acquired by outside exposures from pollution, environmental contaminants, nutrition and more. If you would like to know more about genes and gene expression, check out our blog here: How Nutrition Affects Your
Vomiting is one of the most common reasons owners take their dog to the vet. Here at My Pet Nutritionist it is a common symptom too, but it is often misperceived for regurgitation. There are a number of reasons for both, and they are very different mechanisms. So, let’s first establish the difference between vomiting and regurgitation, and focus specifically on reasons why your dog may be regurgitating. What’s the difference between vomiting and regurgitating? Vomiting is an active process, where the dog is forcefully ejecting the contents of their stomach or intestines. It is often preceded by sound. Food is usually at least partially digested, or it may be bile that comes up. In vomiting you will notice signs of nausea, like drooling or lip licking. Regurgitation is more passive and usually happens while a dog is eating or shortly afterward. There is usually no sound beforehand. Regurgitation is often just water or undigested food. Regurgitation can be common if a dog eats something that is too large – think large bones or chews. Some dogs will attempt to re-ingest it as soon as they’ve regurgitated it. But there are also some other reasons for regurgitation. 1) Stress Stress is a response in the body –and it is similar across humans and dogs. When exposed to a stressful trigger, the sympathetic nervous system fires up. During this process, resources are directed away from the digestive system and so digestive function is compromised. This can lead to the development of acid reflux which is one of the more common reasons for regurgitation. Stress has also been seen to affect oesophageal sensitivity. During stress, corticotropin releasing hormone plays a key role. This hormone is regularly implicated in hypersensitivity (which is why conditions like IBS are more common in those who are anxious or stressed). But what it means is that the oesophagus is more sensitive to mechanical distension, chemical stimuli and more, which may lead to regurgitation. 2) Reduced Mucosal Integrity In the same strand, mucosal integrity also influences oesophageal hypersensitivity. Just like we have a barrier in the skin and gut, we also have an oesophageal one. It too is made up of tight junctions and has its own plethora of defence mechanisms, including a mucosal barrier. But the presence of acid, in cases of acid reflux can injure the oesophageal epithelium and so, in turn, it damages the mucosal barrier, along with the tight junction formation. During attempts to repair, the inflammatory response is called to action, and animal studies into oesophageal damage have suggested it is a double-edged sword. This inflammatory response has been seen to lower oesophageal pressure through its action on smooth muscle which, not only allows for further reflux of acid,but also then delays acid clearance. Findings Here. The take home here is to restore mucosal integrity as soon as possible and modulate inflammation with ingredients such as l-glutamine, slipper elm, deglycerised and marshmallow root. Gut Guardian 3) Good Stress You may notice that your dog is more likely to regurgitate if they eat too soon after exercise. There is such a thing as good stress, but the response in the body will be the same. When your dog is running, chasing and playing, they are asking their body to move away from homeostasis. Their body will need compounds at a higher rate than what they are needed at rest. It therefore places their body under stress and so, resources are redirected. Digestion is no longer a required function and energy conversion is more important. The sympathetic nervous system is the functional stress response, the parasympathetic nervous system is the commande rthat walks into a room and states, “as you were!” But this command can take time to be heard, and so, if your dog eats too soon after exercise, the entirety of the parasympathetic nervous system hasn’t yet got the message. Without a fully functioning digestive system,it propels the food back out again. Always be mindful of when you choose to offer meals to your dog. 4) The Food Being Fed Regurgitation immediately after eating is in fact relatively common in dogs – but this doesn’t mean its normal. From experience, we often link it to the type of food being fed, as often in many cases, when the food is changed,the regurgitation stops. This can be for a number of reasons,but in short, the body isn’t liking what is going in. The enteric nervous system (ENS) is a subset of the autonomous nervous system and can function independently of the central nervous system. The enteric nervous system innervates the entirety of the digestive system and ENS neurons become hyperexcitable in the presence of toxins, bacteria, inflammatory and immune mediators. Animal studies have demonstrated hyperexcitability of ENS neurons after sensitization withmilk ingestion, leading to mast cell degranulation and histamine release. What caused the sensitisation in this study isn’t relevant, the note to make is that hyperexcitability can occur after sensitization, leading to aberrant enteric function. And so, it pays to consider an inflammatory/immune component in cases of chronic regurgitation. An elimination diet may be useful in this case. Check out our blog for more information. Here Equally, an easily digestible recipe such as white fish, can help, if fish is well tolerated. Low Fat Fish Of interest here is the crosstalk between the microbiome and the enteric nervous system. ENS nerves are thought to detect microbial products because germ-free animals exhibit significantly altered enteric function. A healthy microbiome is therefore crucial for the correct digestive messages to get where they need to go. To support your dog’s microbiome, check out our blog: Here 5) Structure There are cases where the structure of the oesophagus can result in frequent regurgitation. This can be a developmental abnormality or blockage. A thorough exam would be necessary to establish the severity of any structural issue. Summary In many acute cases of regurgitation, acid reflux often comes intoplay. If you would like to learn more then check out
Did you know that body wasting is found in 65-90% of patients with advanced liver disease? These patients often develop micronutrient deficiencies which ultimately results in malnutrition. Being a more common disease than we’d like to see here at My Pet Nutritionist, it is clear that there are nutritional implications in any treatment plan. For that reason, we thought we’d explore liver disease in a little more detail, with specific reference to food choices. What is Liver Disease? Liver disease can present in many different ways – it can range from chronic hepatitis, acute liver failure, portosystemic shunts to hepatic encephalopathy. For more information on these specific manifestations, check out our blog here. Here you will also find any signs and symptoms to look out for. But before we get into what happens when it goes wrong, let’s look at what a healthy liver does. The major functions of the liver include: Bile production: Bile helps the small intestine breakdown and absorb fats, cholesterol, and those fat soluble vitamins. Bile consists of bile salts, cholesterol, bilirubin, electrolytes, and water. Absorbing and metabolising bilirubin: Bilirubin is formed by the breakdown of haemoglobin. The iron released from haemoglobin is stored in the liver or bone marrow and used to make the next generation of blood cells. Supporting blood clots: Vitamin K is necessary for the creation of coagulants that help clot the blood. Bile is essential for vitamin K absorption and is created in the liver. If the liver does not produce enough bile, clotting factors cannot be produced. Fat metabolisation: Bile breaks down fats which makes them easier to digest. Metabolising carbohydrates: Carbohydrates are stored in the liver, where they are broken down into glucose and siphoned into the bloodstream to maintain normal glucose levels. They are stored as glycogen and released whenever energy is needed. Vitamin and mineral storage: The liver stores vitamins A, D, E, K, and B12. The liver stores iron from haemoglobin in the form of ferritin, ready to make new red blood cells.The liver also stores and releases copper (which is why copper toxicity in dogs is associated with liver failure). Filters the blood: The liver filters and removes compounds from the body, including hormones and compounds from outside the body, like medications. For more information on detox, check out our blog here. Immunological function: The liver is part of the mononuclear phagocyte system. It contains high numbers of Kupffer cells that are involved in immune activity. These cells destroy any disease-causing agents that might enter the liver through the gut. Production of albumin: Albumin is a protein found in the blood. It transports fatty acids and steroid hormones to help maintain pressure and prevent the leaking of blood vessels. It is the higher circulating albumin found in dogs that suggests they possess an increased fat oxidation capacity, in comparison to humans. Synthesis of angiotensinogen: This hormone raises blood pressure by narrowing the blood vessels when alerted by production of an enzyme called renin in the kidneys. But perhaps the most interesting function of the liver, is its ability to regenerate. In mice, if two thirds of their liver is removed, the remaining tissue can regrow to its original size within 5-7 days! In humans, this process takes slightly longer, but it can still occur. In dogs, the mechanism is thought to occur similarly to that in the mouse., but maximum response is seen after three days, as opposed to 24-hour peak in rat regeneration. Findings here Liver Guard This regeneration is helped by a number of compounds, including growth factors and cytokines like: hepatocyte growth factor insulin transforming growth factor-alpha epidermal growth factor interleukin-6 norepinephrine Micronutrients to Support Liver Health Almost all chronic liver diseases are under the background of elevated oxidative stress. Great sources ofessential antioxidants are foods rich in vitamin C, vitamin E, and trace element selenium. Plant foods also contain compounds that have antioxidant activity, such as ascorbic acid, beta-carotene, coenzyme Q10, curcumin, ellagic acid, epigallocatechin gallate, lipoic acid,lycopene, N-acetyl cysteine, quercetin, and resveratrol. Blueberries This versatile berry contains anthocyanins, an antioxidant, protecting the liver from oxidative stress. Studies have found that in the livers of rats, such protective compounds found in fruits like blueberries slowed the development of scar tissue, and may be useful in the prevention of hepatic fibrosis. CruciferousVegetables (Brussel sprouts, broccoli) Not only does this family of vegetables provide a wide range of nutrients and health benefits, they also have the added ability of increasing the liver’s natural detoxification enzymes and improving overall liver function by decreasing oxidative stress. Findings here Nuts Nuts, which are high in healthy fats and Vitamin E (a powerful antioxidant) as well as other phytochemicals, have shown potential for treating non-alcoholic fatty liver disease by reducing inflammation and fat accumulation in the liver. Fatty fish (mackerel, tuna, salmon, trout) Consuming fatty fish that are high in omega-3 fatty acids regularly can modulate inflammation and enzyme levels. Findings here A review of plant-based foods for liver health indicated the following as beneficial: broccoli carrots collard greens kale sweet potato cabbage banana papaya pomegranate watermelon Findings here Patients with liver disease are advised to avoid nightshade plants like tomatoes and eggplant as they can become hepatotoxic. Macronutrients to Support Liver Health The liver plays a crucial role in the metabolism of proteins along with carbohydrates and fats. It carries out four main functions in protein metabolism. The first is the formation of blood proteins. These blood proteins include clotting factors, carrier and transport proteins, hormones, apolipoproteins, and other proteins involved in homeostasis and the maintenance of pressure, such as albumin. The liver is also involved in amino acid interconversion. Amino acids are divided into two groups, essentials—those that the body is unable to produce,which must be obtained from the diet and non-essentials, those that the body can synthesise. The liver is able to alter the structure of amino acids and transfer amino radicals to a keto acid to produce the amino acids needed for the body. This process is critical in many body functions, especially gluconeogenesis. The third function is amino acid deamination, or breakdown, the by-products
Being the most common clinical condition in adult dogs, periodontal disease raises the flag on why dental care is so important in optimal canine health. Sadly, here at My Pet Nutritionist, we see it, a lot. Periodontal disease begins when bacteria in the dog’s mouth forms to create a substance called plaque. The plaque sits on the surface of the teeth and with the help of saliva, it hardens to form tartar. Not only does it sit on the teeth, plaque and tartar seeps into gum lines which causes inflammation. Over a period of time, this inflammation and presence of bacteria causes damage to the structures surrounding the teeth; causing receding gum lines and eventually tooth loss. These bacteria can also travel to other parts of the body, causing a range of additional health concerns. So, let’s look at periodontal disease in more detail and what we can do to prevent it! But, before we get to the diseased mouth, let’s take a look at a healthy mouth. The Canine Mouth Puppies are born without teeth and they then develop 28 of them. They will shed these between 4-6 months of age as their 42 adult teeth erupt. A dog will possess: incisors canines premolars and molars Incisors are used for cutting food; dogs have 6 upper (maxilla) and 6 lower (mandible). Next come the canines, which are used to grab and tear food, there are 2 canines in the mandible and 2 in the maxilla. The premolars are used for chewing, tearing, and biting; there are 8 in both the mandible and maxilla. Finally, molars are used to crush food; dogs have 4 in the maxilla and in the mandible. Teeth in fact provide the first step of digestion, but over their lifetime and in consideration of genetics and poor hygiene, many dogs will lose most, or all of their teeth. Dental Disease From the moment a tooth erupts it is exposed to food, saliva, and bacteria. Periodontal disease occurs when there is a buildup of bacteria in the mouth, which forms plaque. Eventually,this hardens to form tartar. This can sit in the gum line causing inflammation, known as gingivitis. Left untreated, further harm occurs which results in periodontitis, where teeth fall out and damage can occur to the surrounding bone. Signs your dog has dental disease: Bad breath Pawing at his mouth Reluctance to eat Food or toys will have blood on them Smaller breeds are statistically more likely to suffer with periodontal disease, as are brachycephalic breeds. Their teeth are often closer together which means food and bacteria can more easily get stuck. But what is also interesting is that it is generally accepted that the inflammation and resulting tissue damage is due to an improperly regulated immune response to bacterial infection, and not solely from the bacterial pathogens themselves. This suggests that if your dog already has immune mediated health concerns, then they may be at a higher risk of dental disease. Findings here The point to make is that gingivitis is thought to be reversible, whereas periodontitis is not. Not only is the mouth and teeth a concern, but the bacteria found in the mouth of your dog can be released into the circulatory system, which then travels through the body. It has been found to damage cardiac tissue causing endocarditis (infection and inflammation in the heart). Studies have also shown that periodontal disease is linked to increased insulin resistance and kidney, and liver issues. Findings here All things considered, prevention is certainly better than cure, so what can we do? 1) Avoid ultra-processed refined foods Ultra-processed food is defined as any food that undergoes multiple processes like extrusion and milling. They may also contain added ingredients that are highly manipulated. Sadly, many dry based dog foods fall directly under this definition. In human Hunter-gatherer studies, it is demonstrated that cavities and gum disease were a rarity, and this remains in modern times; Aboriginals living a traditional lifestyle do not generally get dental disease until they adopt a Western diet. There are a number of reasons for this. The mouth, just like the gut contains its own microbiome. It is a community of microbes that maintain balance; the good guys can keep the bad guys in check. Not only do ultra-processed foods skew the balance in the mouth, but they do also the same in the remainder of the digestive tract. As we know, the gut houses much immune tissue, and so it does in fact train the immune response. As we mentioned early, it is thought that much of the damage originating in the mouth is due to an improperly regulated immune response and not solely the bacterial pathogens themselves. For this reason, we would advocate the removal of an ultra-processed diet for oral and gut microbiome health. For more information on the microbiome in your dog, check out our blog here. 2) Dental Sticks There are a number of chews on the market promoting oral health, but it is actually the mechanism of chewing that helps to reduce build up. Chewing stimulates saliva which produces anti-bacterial agents, helping to keep the mouth clean. Not only this but the abrasion that occurs during chewing helps to scrape deposits off the teeth. What type of chew is best? Here’s what the data suggests: Raw bones reduced mouth bacteria by 79% Daily brushing reduced it by 70% and, Marketed dental chews reduced it by 54-60%. Findings here Raw bones lead the way in reducing bacteria,and the added bonus? You know exactly what you are feeding. There is no long list of ingredients to consider. If you are opting for raw bones, ensure they are a manageable size for your dog; chicken necks and wings are a great place to start if you’ve never fed them before! If you’d learn to learn more about the benefits of chewing for your dog, check out our blog here. 3) Diet It is thought that periodontal disease may be related to
Would you believe that around 70% of the consultations we carry out here at My Pet Nutritionist are surrounding allergies? The reasons for this are largely multi-factorial and bigger than the scope of one blog article, but as in the words of someone much smarter than us – you’ve got to start somewhere – so we thought we’d explore histamine in a little more detail. What it is, what it does, if indeed it is found in foods and whether there is anything, we can do to reduce the load. So, let’s get cracking. What is histamine? Histamine is a transmitter in the nervous system and a signalling molecule in the gut, skin, and immune system. It is synthesised from the amino acid histidine which is in fact an essential amino acid for humans and dogs. Before we knew better (and in some labs we still don’t), animal studies established that histidine deplete diets result in dog death! Findings here Histamine is primarily associated with the functioning of the immune system. During an immune reaction, histamine is released and contributes to the physical changes necessary for the immune system to fight the pathogen, including the increase in blood pressure, temperature, swelling, and constriction in the lungs. Like all things in the body, histamine needs receptors for it to do its job and there are especially high concentrations of histamine receptors found in the lungs, skin, blood vessels, and gastrointestinal tract. Histamine is stored in granules in mast cells throughout the body and as we know mast cells mediate inflammatory responses such as hypersensitivity and allergic reactions. The granule protects the histamine; if histamine could float freely it would degrade very quickly. Histamine is released from those granules in response to tissue injury resulting from cold, heat, toxins, and trauma. As noted, there are numerous histamine receptors throughout the body. H1 and H2 receptors are of most interest in the hypersensitivity and allergic response (but there are H3 and H4 too). H1 receptor binding results in a range of actions. Peripheral sensory neurons are acted upon which causes itching and sometimes pain. Intestinal smooth muscle is affected causing constriction, cramps and possibly diarrhoea. H1 receptor binding can result in secretory mucosa causing bronchi and nasal mucus. Lastly the pulmonary smooth muscle can be affected resulting in constriction. There are some tissues that have both H1 and H2 receptor binding sites. This includes the cardiovascular system. Histamine binding here drops blood pressure by widening the blood vessels. It also increases heart rate. There are also dermatological effects resulting in increased permeability. This is often described as the triple response resulting in the reddening of the skin, wheal formation and an irregular “halo” flare, also known as hives. H2 receptor binding sites are more commonly seen in the stomach itself. Histamine can bind to parietal cells stimulating the secretion of gastric acid. This is why antihistamine medication is sometimes implicated in digestive dysfunction due to the lower secretion of gastric acid – which is ironic, when partially digested proteins can then become antigenic. H1 receptors are involved in type 1 hypersensitivity reactions (involves immunoglobulin E – IgE – mediated release of antibodies), H2 are involved in Th1 lymphocyte cytokine production, H3 are involved in blood-brain barrier function and H4 are also expressed on mast cells exacerbating histamine and cytokine generation. The long and the short of it, histamine stimulates inflammation and is a prominent contributor to hyper sensitivities and allergic disease (but it is only one of many mediators of allergic disease). Histamine kick starts the processes to get rid of the offending particle/s – whether this is to sneeze pollen from your nose, or to expel food allergens from the gut, but it also plays a role in wakefulness, appetite, and endocrine homeostasis. So, histamine is in fact necessary to maintain homeostasis (balance in the body). But there can be too much of a good thing. Histamine is released to carry out a function and then it is removed by a few different pathways. The enzymes we are particularly interested in are diamine oxidase (DAO) along with histamine-N-methyltransferase (HNMT). DAO inhibition or disruption can result in disproportionate amounts of histamine in the body which can result in a range of GI symptoms along with cardiovascular, respiratory, and skin complaints. Disruption of HNMT function, on the other hand, tends to affect the nervous system. HNMT inactivates histamine by transferring a methyl group, so methylation is a key process in maintaining HNMT activity. Methylation is a relatively simple process, but it occurs billions of times every second! It underlies the proper function of virtually every body system. It is dependent on certain key nutrients like folate in its active form, methyl folate, B12 and B6. There are a number of factors that can affect methylation, from nutrition to genes, but stress and vaccination is a major drain on it. The stress response is a sequence of processes that relies on methylation, depleting key nutrients as it goes. Therefore, if methylation isn’t efficient, HNMT isn’t efficient, and histamine can become imbalanced affecting behaviour, sleep, appetite, immune function and digestion. A range of factors can increase histamine in the body such as infections, B12/folate deficiency, magnesium deficiency, stress, inflammation, trauma and exercise. Not only that but certain gut bacteria produce histamine. DAO and HNMT can become flooded when there is a high histamine load, subsequently affecting breakdown. Histamine load can be increased by the ingestion of high-histamine foods too, but the release of it can also be promoted in the body, by foods we know as liberators. The following list is of foods to avoid if opting for a low-histamine approach to hypersensitivity, whilst getting to the bottom of things. Fermented foods (kefir, sauerkraut etc, prebiotics) Tripe Vinegars (including ACV) Long-stored nuts Beans and pulses Canned foods Citrus fruits Banana Wheat germ Spinach Canned fish (salmon can contain more histamine than most) There is also discussion around yeast behaving as a histamine generating catalyst, so the general rule
Have you ever noticed that the wolves found in Yellowstone are rarely obese? Even the alpha males, who in theory could have access to all the kill they choose, maintain a lean weight. Do they perfectly balance their calories in with their calories out? Whilst not impossible, it’s a slight stretch of their intuition and it demonstrates on a simplistic level, why the CICO model doesn’t really answer enough questions when exploring the concept of obesity. In our last My Pet Nutritionist blog article, we explored a range of ideas that can contribute to obesity in pets, but there are many more schools of thought, so we thought we’d explore another in a separate article. One of them being hormones. All of the fat found in cells is stored in the form of triglycerides. Fatty acids are converted into triglycerides for storage and then for fat to be used as energy, they are freed back into fatty acids. Getting fat is the process where triglycerides are created more quickly than they are broken down. This flow of fatty acids is regulated by a range of enzymes and hormones. This isn’t surprising when we consider the role of growth hormone, it is what drives the growth of children and adolescents. If you are considering bodybuilding, steroid hormones are used to increase bulk and if you take a trip down memory lane, chickens were injected with hormones in the 50’s to increase their size too! Findings here It seems that, on a simplistic level, certain hormones cause fat cells to suck up fatty acids more readily than they otherwise would or slow down the rate at which triglycerides are converted back. Both oestrogen and testosterone have been shown to decrease the rate at which certain cells take up free fatty acids, which results in keeping the fat cells relatively small (and why in humans you will notice differences in fat gain between males and females). This is why after neutering your pet, you are advised to monitor their weight as more often than not, they gain weight. This issue here is demonstrated by a study conducted in the early 1970’s. A professor named George Wade wanted to explore how animals regulated their fat supplies. He had two groups of rats and removed their ovaries. The first group then was given free access to food and they could eat as much as they desired. They subsequently ate more than they had before the surgery and became obese. The second group were restricted to the same number of calories they had eaten before the surgery. Their environment was also kept the same. But this second group too became obese it just occurred through a different mechanism. They simply became less active. With the removal of the hormones, it is thought that the uptake of the free fatty acids was unregulated, resulting in more fatty tissue. With the drop in lipid levels, group one sought to replace the circulating levels with more food, but with the absence of food in the second group, they simply became less active to account for the shortfall. The implication of hormones in fat regulation is also demonstrated when lesions in the brain disrupt the hypothalamus. The ventromedial hypothalamus is one of the most hormonally active areas in the brain, and lesions here have resulted in the development of obesity. Leptin largely exerts its influence in the hypothalamus and leptin has a crucial role in regulating food intake and maintaining metabolic homeostasis (balance). Being another hormone, leptin is secreted mainly by adipocytes. Plasma leptin levels are significantly associated with body mass index and total body fat. It is generally accepted that total fat mass is the strongest predictor of circulating leptin. The discovery of leptin made it clear that adipose tissue (fat tissue) is not only a regulator of body weight but also an endocrine organ with feedback loops between the brain and peripheral tissues. Leptin levels decrease during fasting or energy restriction and increase during refeeding, overfeeding and sometimes during times of stress. Several metabolic and hormonal factors influence the synthesis and secretion of leptin in the body such as cytokines, cortisol, catecholamines, fatty acids, glucose, and insulin. Which brings us to another hormone that is intricately involved in obesity in our pets. Insulin Insulin is deemed an anabolic hormone; it works to accelerate the rate at which nutrients are put together to make new tissues. Insulin is well known for its role in clearing glucose from the bloodstream and regulating blood sugar balance. We’ll use the dry fed dog to explore this a little further. When carbohydrates are digested by the dog, they are broken down into glucose. Carbohydrates can be complex (being longer chains of molecules and taking a little longer to be broken down) or simple (broken down quickly and easily). Ultimately, when they exit the digestive tract and find themselves in the bloodstream, they exist as glucose. When blood sugar levels start to creep up, insulin is called to action. Insulin is like the porter in the hotel; it shuttles glucose out of the bloodstream and opens the doors of where it needs to go. This can be to cells or muscles to be used as energy, but if it isn’t needed there, it can be stored (in adipose tissue). Think of it like when you’ve got an early check out and leave your luggage at reception until you’re due at the airport. But what insulin also does is blocks the conversion of triglycerides back; this makes absolute sense as it wants to prioritise the use of glucose as energy to get it out of the blood stream! But what this means is that insulin is in fact a fat regulator. Now we know glucose can be generated from non-carbohydrate sources through gluconeogenesis, but the issue for the dry fed dog, is that these diets often score incredibly high on their carbohydrate content. Due to the range on the market, it can be anywhere up
