Possibly one of the most common ailments that we find in the dog world – some dogs just seem to react to everything! But, if we know how allergies and sensitivities develop, is it something we can tackle? Let’s take a look and consider some top tips to support your dog’s health. What is a dog allergy? An allergy is an unnecessary immune response to an innocuous substance. True allergies are often fatal. More often than not we are faced with sensitivities – which are still an immune response. What is the immune system? The purpose of the immune system is to defend itself and keep microorganisms like bacteria, viruses, and fungi out of the body and then destroy any if they happen to get in. It has three lines of defence. The innate immune system provides the first line of defence; broadly divided into physical/chemical barriers. The physical barriers include the skin and the lining of the digestive and respiratory tract. You can think of the body like a sausage; the skin, keeps everything in, but also things out. Chemical barriers include tears and saliva along with gastric acid. But also, the microbiome – which is the community of microbes found in the mouth, lungs, gut and on the skin. We then have the innate immune system – which is for want of a better phrase a row of white blood cells (and other participants) that engulf and destroy invaders. The third defence is acquired or adaptive immunity – this is the memory bank. The cells involved in this response help the body remember antigens that it has encountered before – so it can mount a quicker response before the harmful pathogen causes any damage. The immune system is trained to recognise its own cells as self and leave them to do their jobs. It is trained to recognise anything that isn’t self and attack it. When it works, it works brilliantly and, well, us and our dogs survive. But, it can get a little too enthusiastic and start responding to things it doesn’t really need to. This is what we see as autoimmunity, but also allergies and sensitivities and there are a number of reasons for this. Allergies and Sensitivities First of all, we may be dealing with an immature immune system, and this all starts back in puppyhood. When we talk about immune responses, we tend to reference Th1 and Th2. They are both necessary responses, but a Th2 response is more commonly associated with allergy. During pregnancy, a strong Th2 response is present to reduce the risk of miscarriage. What this means is that puppies are born with a Th2 dominance. This then needs to be balanced and the way in which this occurs is through microbial exposure. This is what we know as immune tolerance – the immune systems develop through exposure to controlled challenge. The immune system is like a computer; it has software, but it needs data. The microbial ecosystem in various mucosal sites is important for the development of the immune system. The young gastrointestinal tract is colonised soon after birth by a variety of commensal bacteria that influence the development of the immune response both in the gut and systemically. The mucosal immune system in the gut must avoid adverse immune responses to dietary antigens and commensals in the new microbial ecosystem while remaining able to mount an effective response to pathogenic organisms. In an ideal world, our pets will develop a heathy immune system, and they will have sufficient immune tolerance but also eliminate threats when necessary. But we don’t always live in an ideal world. Gut Guardian br] So what else can cause issues with immune responses? Often allergies and sensitivities are associated with poor barrier function; so there may be damaged or broken skin, a poor microbiome, or damage to the integrity of the gut. Think of it like an army. If you have a row of soldiers who are standing shoulder to shoulder, you stand a good chance against the enemy. Once soldiers start falling, opportunities arise for the enemy to get through. When skin is damaged, antigens spot their opportunity and sneak in through the gaps. The same occurs in the gut. Cells sit tightly together, but when cell integrity fails, under digested food particles and pathogens see their opportunity and sneak out into circulation. The immune system spots these particles – realises they shouldn’t be there, so mounts a response. Inflammation is a key part of this response. The issue is when the barrier remains compromised, more particles sneak through and so you end up in a chronic state of inflammation. Barrier dysfunction can occur for a number of reasons: Genetic glitches Microbiome dysbiosis Long-term use of medication Toxins Environmental exposure Detoxification Pathways The more inflammatory compounds you have in the presence of a response, the more anti-inflammatory compounds you will need to counter this response. There will also be a heightened need for compounds that break down inflammatory molecules like histamine. Those suffering with allergic disease often have a higher baseline of histamine, and so clearance of this is important too. What this means is that detoxification pathways need to be running as smoothly as possible. Liver Guard Detoxification of dietary histamine normally occurs in intestinal epithelial cells via the enzyme diamine oxidase (DAO) as well as histamine-N-methyltransferase (HNMT) in the liver. What’s interesting is that there are polymorphisms in the genes that code for the DAO enzyme, but certain medications, including over the counter products are seen to inhibit the activity of DAO enzyme too. They include: Analgesics – morphine, NSAIDs Antiarrhythmics Antibiotics Antifungals Antimalarial Diuretics Motility agents Muscle relaxants Vitamins – ascorbic acid, thiamine In addition, detoxification pathways in general are nutrient demanding and they also produce a high number of free radicals. Sufficient levels of key vitamins and minerals like vitamin A, C, E, B1, B2, B3 and iron, along with cysteine are essential. Does My Pet Need To
We sometimes talk about intolerances and allergies like this is the only thing that can cause your cat or dog’s itching. There can be so many reasons, layered reasons and some more serious than others. Here we explore some of the undetected and misdiagnosed reasons for your dog being itchy. Adrenal function The adrenal glands are located just in front of the kidneys. You will recognise them from when we discuss the stress response more often than not. The adrenal gland has 2 parts—the cortex and the medulla. The adrenal cortex is subdivided into 3 layers, and each layer produces a different set of steroid hormones. The outer layer produces the mineralocorticoids, which help regulate sodium and potassium salts. The middle layer produces glucocorticoids, which are involved in metabolising nutrients and reducing inflammation and immune responses. Finally, the inner layer produces sex hormones such as oestrogen, progesterone, and androgens. The adrenal medulla plays an important role in response to stress or low blood sugar levels in the body. It releases adrenaline and noradrenaline, both of which increase heart rate and blood pressure, increase blood sugar and slow digestion; the hallmark responses when us or our dogs are exposed to a stress trigger. The adrenal glands are part of the endocrine system – which is simply a system of glands that release chemical messengers called hormones. The endocrine system influences almost every cell, organ, and function in the body. So, if there is any issue in any part of it, things can start to go wrong. The two most common ways in which adrenal glands cause health issues are by producing too little or too much of certain hormones, which leads to hormonal imbalances. Hyperadrenocorticism (Cushing’s Disease) due to an excess of cortisol production frequently causes dogs to itch, lose hair, have thin skin with dark pigment, drink excessively and have recurring skin problems. But this raises another point, even if there are no physiological issues with the adrenal glands, high cortisol levels due to daily stress can also lead to itchy skin! Thyroid Function We’ll continue with the hormones for a minute and look at thyroid function. The thyroid is a butterfly shaped gland found in the neck. One of its main functions is to produce hormones to regulate the body’s metabolism, the process that turns food into energy. This too can produce too many hormones, or too few. These conditions are known as hyperthyroidism and hypothyroidism respectively. Hypothyroidism Hyperthyroidism Hyperthyroidism in Cats Skin issues are regularly noted in times of thyroid dysfunction, and this includes itchiness. Kidney Function Intense itchiness often accompanies late-stage kidney disease, and whilst the jury is out on the exact reasons behind it, it is thought that it’s relating to the build up of toxins in the body. This leads us nicely into the same itchy symptoms associated with early-stage liver disease, and this is considered for similar reasons. Detoxification Detoxification is carried out by a range of mechanisms, and this comes in particularly handy if one pathway is overwhelmed, another can pick up the slack. The Liver The liver neutralises a range of toxic chemicals, both those produced internally (waste from used hormones or neurotransmitters for example) and those from the environment, like air pollution, pesticides, and food additives. It does this by filtering the blood to remove large toxins, synthesising, and secreting bile and lastly enzymatically disassembling unwanted chemicals found in the body. Liver Guard Enzymatic Detoxification This enzymatical detoxification occurs in three phases. Phase I directly neutralises chemicals and changes them into new metabolites. These are then processed by phase II enzymes. This is known as the conjugation phase, which in short, liver enzymes attach small chemicals to the toxin. There are many ways in which this is done, it all depends on the type of chemical the liver is trying to manage. Phase I results in high levels of reactive oxygen species so antioxidant levels are key in modulating potential damage. Phase II is nutrient demanding and sufficient levels of key vitamins and minerals like vitamin A, C, E, B1, B2, B3 and iron are essential. Phase III is the elimination phase. For optimal excretion of toxins through the digestive system, gut health is vitally important. Maintaining the mucosal barrier is key for gut health along with supporting motility. The kidneys will also filter and process toxins from circulation, excreting them as urine. The skin also forms as an elimination pathway. This is why detoxification issues can result in skin issues. In cases of liver disease, it is considered that bile salt deposits under the skin, which results in itchiness. The most important thing to do to support detoxification is to avoid exposure in the first place, so consider how much you and your dog are exposed to: Pesticides Heavy smoke Phthalates Mould Medications like steroids, antibiotics, and painkillers Heavy metals Cleaning products Air fresheners Eating foods cooked at high temperatures (most commercial dry foods) This list is not exhaustive, but it is a place to start. This mechanism also applies to vaccines. There is increasing evidence that over-vaccination is associated with the development or aggravation of immune-mediated disorders and chronic diseases in individual pets that are genetically predisposed. The primary role of the immune system in dogs is to protect against foreign invaders, or abnormal cells that invade or attack. The immune system must distinguish between self and non-self. Substances that stimulate a response are antigens. These can be contained within bacteria, viruses or microorganisms or cancer cells. They may also exist on their own, like pollen or food particles. There are three lines of defence, physical barriers, nonspecific immunity, and specific immunity. But the immune system does not always function properly, it can be underactive and overactive. An underactive system puts the animal at risk of infection, but an overactive immune system can attack parts of its body that it misidentifies as being foreign. This is what happens in autoimmune conditions. The immune system can also overreact
Amongst the foods marketed for pets, grain free is sitting front and foremost. Whilst we specialise in a range of health issues here at My Pet Nutritionist, we also consult on the most appropriate diets for pets. One of the questions we have been asked, does my dog need a grain free diet? Well, we see huge benefits to a whole or cooked fresh food diet, which is technically grain free, but we know this isn’t what you mean, so let’s take a look at where grain free diets came from and how they have found their way into many homes around the world. Grain Free Diets The concept of a grain free diet likely came from human literature. Grains are in fact a staple in many traditional diets, but a number of books appeared on bookshelves resulting in people cutting this food group out. Grains include wheat, spelt, rye, corn, millet, rice, sorghum, and oats. You’ll notice that both gluten and non-gluten grains are included. In addition, many people opted to cut out products derived from grains like rice syrup or high-fructose corn syrup (which is actually great!). There were a number of reasons for the demonisation of grains. Firstly they were thought to contribute to inflammation in the body, and therefore be a causative factor in many inflammatory conditions. This could be due to the lectin content found in grains. Lectins are often described as an antinutrient and as they are found in potatoes, beans, lentils, peas, soybeans, nightshade vegetables and you guessed it, grains. Lectins are carbohydrate binding proteins present in most plants, especially seeds and tubers like cereals, potatoes, and beans. Their original purpose was protection. They would produce an inflammatory response in the animal that ate them – so they wouldn’t eat them again. Humans and Dogs are largely unable to digest them, but friendly bacteria in the gut can lend a hand. At high dietary levels, it is thought that lectins cause damage to the structure of the brush borders of the small intestine. In lectin fed rodents, the mucosal membrane in the small intestine was stripped, compromising the gut integrity. This compromise has also been linked to abnormal bacterial proliferation. Findings Here Furthermore, some bacteria responsible for urinary tract infections contain lectins specific for the sugar mannose and use these lectins to bind tightly to mannose-rich tissue in the bladder walls – therefore initiating infection. D-mannose supplementation provides a decoy for these bacteria. Lectins also cause discharge of histamine from gastric mast cells which stimulates acid secretion – and as you know, we obviously need stomach acid, but in the right amounts – not too much, or too little. In addition, animal and cell studies have found that active lectins can interfere with the absorption of minerals, especially calcium, phosphorus, and However, lectins are most potent in their raw state, so cooking can inactivate most lectins. They are also water-soluble, so soaking also removes them too! Grains have also been linked to: Anxious and depressive behaviour Chronic pain However, most studies to date have considered these issues alongside gluten containing grains. Researchers have therefore concluded that the issue may in fact be relating to gluten as opposed to the grain. Grain free diets have been linked to weight loss, reduced inflammation, and modulated blood sugar levels. However, to fully understand the role of grain free diets, it’s pertinent to pick this apart a little further. Many grains contain a carbohydrate content, when grains are refined and processed, like those found in many commercial foods, they become a calorie-rich but nutrient poor food. With the removal of the grain, by default, the calorie content is reduced. This same premise applies to inflammation. It is well established that refined grain intakes have been positively associated with risk of metabolic diseases as well as with inflammatory protein concentrations. Refined grains are milled, a process that strips out both the bran and germ to give them a finer texture and longer shelf life. The refining process also removes many nutrients, including fibre. Refined grains include corn flour and white rice. Whole grains on the other hand haven’t had their bran and germ removed by milling; therefore, all of the nutrients remain intact. Whole grains are sources of fibre and other important nutrients, such as selenium, potassium, and magnesium. Whole grains include millet, bulgur, buckwheat, barley, and oatmeal. This is relevant when we consider how grain free diets have been linked to modulating blood sugar levels. Grains are naturally a source of carbohydrates. As we know, when carbohydrates are ingested, without naturally occurring fibre, they are digested very quickly, and pass into the blood stream. This results in a spike in blood sugar, which insulin must come and manage. Refined grains are devoid of fibre. Whole grains on the other hand are rich in fibre which may help stabilise blood sugar levels. The take home here is when we are looking at the benefits touted in grain free diets, we must consider the grains that are being referenced. Grain Free Diets and Dilated Cardiomyopathy You will have come across the FDA link between grain-free dry dog foods and dilated cardiomyopathy (DCM). The issue is suggested to be related to a taurine deficiency. Cats and humans are among the few mammals whose bodies do not make taurine, and therefore must obtain it from their diet. In humans, taurine deficiency is rare because taurine is common in meat and fish food products. In the 1970’s, Quinton R. Rogers of UC Davis showed that a taurine deficiency could cause degeneration of the retina in cat’s eyes. Kittens born to taurine deficient mothers are often blind and show many abnormalities such as impaired gait. For this reason, in the 1980’s new cat feeding guidelines were introduced, stating a minimum level for taurine in cat food. But, in later years it was also found that taurine plays a role in regulating calcium entry into heart tissue every time it beats. Researchers
In our last blog we considered the importance of minerals for your dog’s health, but we only got so far. There are further minerals, ones we deem trace minerals, which are also important to optimal health. So, let’s get cracking. Chromium Within human realms, chromium is mostly talked about for its role in modulating blood glucose levels. It is considered that chromium acts as a cofactor that can enhance the effects of insulin on target tissues. In states of chromium deficiency, abnormal glucose utilisation results along with increased insulin demands. Findings Here Along with potentiating the action of insulin, chromium increases uptake of amino acids into muscle, heart, and liver and enhances protein synthesis. It also plays a role in regulating blood lipids. Increased Risk of Deficiency: Diets high in sugars and refined carbohydrates (results in increased urinary excretion of chromium) Increased stress (physical activity, infection, trauma or illness) Pregnancy Ageing Sources of Chromium: Broccoli Turkey Chicken Brewer’s Yeast Cobalt One of the things you may not have realised about Cobalt is that it is an integral part of Vitamin B12 (cobalamin – get it?). Why Your Dog Needs Vitamin B12 Cobalt is therefore essential for the function of cells. It is involved in the production of red blood cells and the production of antibacterial and antiviral compounds that prevent infections. This mineral plays a key role in the metabolism of fats and carbohydrates as well as the synthesis of proteins and conversion of folate in their active form. In the nervous system, cobalt also plays a role in the prevention of demyelination, which is a condition that results in damage to the membrane that covers the nerve fibres in the brain and spinal cord. This ensures efficient nerve transmission. Copper Copper has a number of functions throughout the body including: Energy production in mitochondria Mobilisation and transfer or iron from storage sites to the bone marrow Synthesis of collagen and elastin in connective tissue Acts as an antioxidant (as zinc/copper superoxide dismutase) Supports synthesis of melanin in the skin Synthesis of adrenaline and noradrenaline in the nervous system Breakdown of serotonin, histamine and dopamine Increased Risk of Deficiency: High intakes of supplemental iron, molybdenum, or zinc Prolonged use of proton pump inhibitors (acid reducers) Gastrointestinal disorders (chronic diarrhoea, inflammatory bowel disease) Increased levels of oxidative stress (air pollution, toxin exposure) Signs of Deficiency: Anaemia Increased vulnerability to oxidative damage Reduced immune responses Abnormal skeletal growth Changes and loss of hair and skin pigmentation Lethargy Excessive copper build-up in the liver can cause liver disease in some dogs. Common breeds of dog that are affected include Bedlington terriers, Labrador retrievers, and Dalmatians. There are clear genetic implications found in Bedlington Terriers which prevents normal copper excretion. Three forms of the disease occur: (i) asymptomatic – in which signs are yet to develop, (ii) acute -seen in dogs up to six years of age, with the sudden onset of severe illness shown as depression, anorexia (not eating) vomiting and possibly jaundice (yellowing of mucous membranes, whites of eyes and skin), and (iii) chronic – seen in middle-aged dogs with signs of chronic liver damage and sometimes failure which may show vomiting, weight loss, jaundice and abdominal swelling. It is considered that many commercial dog foods report total copper levels as higher than recommended, and some home-made diets may not furnish adequate amounts of copper. Findings Here That said, data indicates that copper absorption is greater when diets are animal protein rather than plant protein. Findings Here Iodine An essential mineral, iodine is used by the thyroid gland to make thyroid hormones that control many functions in the body including growth and development. If you would like to learn more about the thyroid gland and the conditions that often affect it, check out our blogs here: Hypothyroidism Hyperthyroidism Hyperthyroidism in Cats Iodine can only be obtained from diet or in supplemental form. Of interest, concurrent deficiencies in selenium, iron or vitamin A may exacerbate the effects of iodine deficiency. Seaweed like wakame are rich in iodine, but other sources include eggs and poultry. Iron Functions: Oxygen transport Oxygen storage as myoglobin Energy production Cofactor for multiple enzymes Production of neurotransmitters and thyroid hormone There are two sources of iron, haem, and non-haem. Haem is found primarily in meat and meat products where non-haem is found in plants. Haem is generally well-absorbed, whereas non-haem absorption is largely affected by other factors. Common inhibitors of iron absorption are phytates, tannins, starch, and proton pump inhibitors. The body has three unique mechanisms for maintaining iron balance and preventing deficiency and overload: Storage of iron Reutilisation of iron Regulation of iron absorption Iron from food is mainly absorbed in the duodenum. Iron can be in ferrous state (Fe2+) or ferric state (Fe3+). Fe3+ is not directly absorbed, but Fe2+ is easily absorbed. In the intestine, Fe3+ is converted by ferric reductases into Fe2+. When required by the body, iron is transported by transferrin to bone marrow and other tissues. Iron is required for the transport of oxygen, oxygen storage in muscle and is also a component of energy production. After absorption, any iron that isn’t needed, is stored as ferritin in the liver, spleen, or bone marrow. During times of high need, iron is then released. Most of the iron in the body is contained within red blood cells. Red blood cells have been noted to have a life span of around 110-120 days but when they reach the end of their life span, they release iron. The resultant liberated iron can be reused to produce new erythrocytes in bone marrow, stored as ferritin or released back into systemic circulation. Iron deficiency anaemia is the common condition associated with decreased iron levels, resulting in low circulating haemoglobin and reduced myoglobin. Iron deficiency is also associated with lower T and B lymphocyte, macrophage, and neutrophil function. Your Pet’s Immune System On the other side of the scale, iron toxicity is generally associated with supplementation. At a
If you have been following any nutrition nerds (including us here at My Pet Nutritionist) then you will have likely come across the terms macro and micronutrients. We tend to reference them more commonly in the human realms, but that doesn’t mean that they don’t also apply to our canine companions (and feline for that matter). When we mention macronutrients we are referencing those needed in larger amounts in the body and they encompass protein, fat and carbohydrates. When we consider micronutrients we are looking at vitamins and minerals. Despite them being needed in micro amounts, they are still biologically necessary to all functions in the body. So, let’s take a look at minerals in a little more detail and see why your dog needs them. What is a Mineral? A mineral is a naturally occurring inorganic solid, with a definite chemical composition, and an ordered atomic arrangement. What on earth does this mean we hear you wonder? Well, let’s break it down. Minerals are naturally occurring, meaning they are not made by humans. They are inorganic, meaning they have never been alive. They are solid, meaning they are not liquid or gas. Each of them has a unique structure and arrangement which is how we know what they are. For the dog we are interested in 17 essential minerals. We have macrominerals which are needed in larger amounts and trace minerals which are needed in smaller amounts. Macrominerals Calcium You’ll likely be familiar with calcium as you were probably told to drink your milk so you would have strong teeth and bones. Calcium is the main structural component of skeleton and teeth, but it also plays a role in blood clotting. In addition, it is involved in the intracellular messaging triggering the contraction of muscle fibres. Calcium also plays a role in fat oxidation and it carries ATP (energy) with magnesium. There is an increased risk of deficiency in: Diets containing large quantities of phosphorus and sodium. Fat malabsorption (fat binds calcium, reducing absorption). Vitamin D deficiency. Diets containing large quantities of oxalates. Signs of Deficiency: Poor bone mineralisation, Muscle cramping and spasm, Increased irritability of nerve cells, Abnormal blood clotting and increased bleeding after trauma. Chloride Chloride is one of the most important electrolytes found in the blood. It plays a key role in controlling the amount of water and type of compounds that go in and out of cells. It therefore plays a crucial role in homeostasis. Chloride also contributes to muscle function and this includes the heart. This mineral helps red blood cells exchange oxygen and carbon dioxide too! Lastly, chloride supports digestive processes through its role in the production and release of hydrochloric acid in the stomach, and as we know, without this, foods won’t be properly digested and subsequently absorbed. Low levels of chloride are usually found alongside existing health issues which result in electrolyte imbalances. Sources of Chloride: Himalayan Salt Seaweed Magnesium Here at My Pet Nutritionist, we have a thing about Magnesium, for good reason. If you want to know more about this trusty mineral, then check out our full blog here: Why Is Magnesium So Important to Your Pet But the one often forgotten role of magnesium is the part it plays in energy, so we’ll do a recap. The bottom line is that insufficient micronutrient intake results in poor ATP production in the mitochondria. Remember that ATP is the currency of energy and the mitochondria is the powerplant of the cell, where it all happens. Magnesium and copper are star minerals for making ATP and without enough ATP or energy, the body hasn’t got enough resources to do what it needs to! In addition, a deficiency in magnesium can lead to mitochondrial damage. Signs and Symptoms of Deficiency: Muscle cramps and spasms Anorexia, nausea, vomiting Arrythmias Sodium and water retention Impaired action of vitamin D Increased Risk of Deficiency: Diets emphasizing processed foods and refined grains (largely nutrient deplete) Strenuous training Periods of rapid growth Intestinal malabsorption Medications (diuretics, steroids, laxatives) As a note, magnesium deficiency has also been linked to increased inflammatory cytokines, so this is a consideration to make in any chronic inflammatory condition. Findings Here Phosphorus Phosphorus in mainly used for the growth and repair of body tissues – it is a component part of bones, teeth, RNA and DNA. In the form of phospholipids, phosphorus is also a component of cell membrane structure and of the body’s key energy source, ATP. Many proteins and sugars in the body are phosphorylated. In addition, phosphorus plays key roles in regulation of gene transcription, activation of enzymes, maintenance of normal pH in extracellular fluid, and intracellular energy storage. A range of foods contain phosphorus, mainly in the form of phosphates and phosphate esters. Phosphorus in seeds for example, is in the form of phytic acid, the storage form of phosphorus. Because many species intestines lack the phytase enzyme, much phosphorus in this form is unavailable for absorption. Low phosphorus levels in the body can include anorexia, anaemia, proximal muscle weakness, skeletal effects (bone pain, rickets, and osteomalacia), increased infection risk, ataxia, and confusion. But in most cases, hypophosphatemia (low phosphorus) is caused by existing health conditions, such as hyperparathyroidism, kidney disorders, and diabetic ketoacidosis. In cases of chronic kidney disease, their ability to excrete phosphorus becomes compromised. This is why low phosphorus diets are often recommended. Kidney Disease Potassium Another electrolyte, potassium is also involved in energy production and membrane excitability and transport. Throughout the body there are a number of functions that are potassium dependent. If potassium is deficient, these enzymes or proteins are unable to carry out their job as they should. For example, one heat shock cognate protein, involved in protein folding, autophagy, apoptosis and cell stability requires potassium to carry out these functions. In a deficit, cell senescence results, along with DNA damage, carcinogenesis, and neurodegeneration. Findings Here The bottom line is that potassium helps nerves and muscles to function correctly, it maintains a
If you’ve been following us here at My Pet Nutritionist for a while then you will likely have come across the concept of the gut barrier, and how when it gets compromised, things can start to go a little awry. Whilst leaky gut is being blamed for all sorts, we’re here to sort fact from fiction and we’ll start with the basics. What is the Gut Barrier? The gut barrier in effect, forms the lining of the gut and it has two main features: the physical barrier and the chemical barrier The physical barrier consists of tight junctions which form a selective permeable seal between adjacent epithelial cells. This “seal” is dynamically regulated by various extracellular stimuli and is closely associated with both health and disease. TJs contribute to the function of the physical intestinal barrier by regulating the paracellular movement of ions, solutes, and water across the intestinal epithelium. It also protects against pathogens and large, harmful molecules. The regulation of these TJs is therefore crucial to a healthy barrier and there are a number of things that can influence this. Immune mediated TJ function is well documented; cytokines play a key role in the integrity of the gut barrier. Tumor necrosis factor-α Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine that is produced mainly by activated T cells and macrophages (cells of the immune system). TNF-α is known to induce cell death and inflammatory response in intestinal epithelial cells and recent studies have also demonstrated that it impairs the intestinal TJ barrier. Findings Here Interleukin-1β Interleukin-1β (IL-1β), another inflammatory cytokine is markedly elevated in intestinal mucosa under inflammatory conditions. In addition, recent studies show that IL-1β causes increased intestinal TJ permeability. Findings Here On the other hand, Interleukin-10 (IL-10) is regarded as an anti-inflammatory cytokine. In vitro studies have demonstrated that IL-10 opposes the cellular functions induced by TNF-α and IFN-γ. It is suggested that IL-10 has a role in the protection of the intestinal barrier by regulation of TJ proteins. Findings Here Pathogenic Bacteria and Lipopolysaccharides It is well established that pathogenic bacteria also alter the intestinal epithelial TJ barrier. The most commonly referenced are Escherichia coli (E.coli) and Salmonella which lead to intestinal inflammation. In addition, lipopolysaccharides (LPS), also called endotoxins, a component of the outer walls of gram-negative bacteria also alter TJ protein assembly. In studies, LPS treatment is seen to increase TJ permeability and induce epithelial cell death. The other part of the barrier is the mucosal layer. Mucous Layer The mucus layer is the very first line of defence that external molecules encounter when they arrive in the gut, it prevents bacteria from directly contacting the epithelial cells, along with toxic substances and digestive enzymes. The main building blocks of the mucus layer are mucin proteins that form a gel-like sieve structure overlying the intestinal epithelium. In the small and large intestine, mucin 2 (MUC2) is the most abundant mucus protein secreted by goblet cells. MUC2 expression is critical in protection against disease, as Muc2 knock-out mice will often develop colitis. Findings Here The ability of mucins to bind water offers another protective element – they moisturise and lubricate, protecting the epithelial cells from dehydration and mechanical stress during the passage of food. Immune regulators are also found in the mucosal layer, which highlights its collaboration with the immune system. Mucous Turnover and Degradation The turnover of the intestinal mucous layer includes mucous synthesis, secretion, and degradation. It is a complex process that needs to be regulated and balanced to ensure optimal protective function. Mucin degradation has been recognized as a normal process of mucus turn-over in the GI tract, starting a few months after birth. Selective intestinal bacteria can degrade mucous glycans as an energy source, suggesting that there is a relationship between the microbiota and the mucosal layer. This is of concern in low fibre diets because in the absence of fibre as a fuel source, the microbiota will switch to mucosal glycans. It has been well established that low fibre diets are associated with a thinner colonic mucosa. Findings Here The rate of mucin turn-over can be modified by bacterial colonization, for example, the intestinal mucous requires the presence of bacteria to develop its full functionality; analysis has shown thin or even absent mucous layer in the colon of germ-free rats. Findings Here In addition, short chain fatty acids can stimulate mucous production. SCFA’s are the end products of microbial fermentation of undigestible carbohydrates with acetate, propionate and butyrate being the most common in the intestinal lumen. Starvation also influences mucin turnover. The mechanism during times of starvation is much the same as on low fibre diets, diverse bacterial species will switch to mucin as an energy source during nutrient deprivation. This poses food for thought in fasting. To Fast or Not To Fast? Finally, the consumption of a Western Style Diet (WSD) has been linked to the impairment of intestinal mucosal function. Animal studies have administered a WSD, high in fat, simple sugars and low in complex fibre and found that in just three days the mucosal layer was diminished. A reduction in MUC2 was found. However, when mice were transplanted with microbiota from a control diet, the mucosal dysfunction was prevented, despite being fed a WSD themselves. This suggests that in addition to dietary choices influencing the composition of the mucosal layer, so too does the microbiota. Your Puppy’s Microbiome What Can Cause Gut Dysbiosis What Can Help Dysbiosis Furthermore, there seems to be a bidirectional relationship between stress and mucosal barrier function. Animal studies have demonstrated that early life stress impairs development of mucosal barrier function, becoming a predisposing factor to intestinal disorders in adult life. Findings Here Can Stress Affect My Dog’s Digestive System 6 Tips for Your Anxious Dog Why Dogs Need To Chew Top Tips to Support Gut Barrier Health: Offer a species appropriate diet Limit toxic exposure Support beneficial microbiome formation and maintenance Limit stress exposure Address existing inflammation If you would
Generally, when we talk about fasting in the human realms, we are talking about intermittent fasting, and the function is largely to lose weight. What this mechanism actually does is reduce overall caloric intake, so by definition, if you reduce calories, there may be a resultant weight loss (note, we say may, because weight loss isn’t always that simple). But, when we talk about fasting in dogs it’s not generally around weight loss, it’s for longevity and improved health outcomes. Here at My Pet Nutritionist, it’s a question we get asked a lot. Should we fast dogs, or not? Let’s look at the science behind it. What Is Fasting? Fasting is not the same as starvation. Starvation occurs when there are no reserves left in the body; with insufficient intake of nutrients resulting in the break down of vital tissues. Fasting is simply a form of reduced calorie intake. What is interesting is that complete or modified fasting is a natural part of the wild canine diet. Wolves, the closest living relative to the dog are a window into dog physiology. When we look at the behaviour and lifestyle of wolves reintroduced into Yellowstone National Park, they show us that they are well designed for feast or famine. When hunting is easy, they may kill every two to three days. Generally, they will first eat organ meats, then muscle. At the end of the two- or three-day period, they then eat the bones and hide, including the fur. In times of low food abundance, wolves have been seen to scavenge bone and hide for several weeks at a time. Findings Here What Happens During a Fast Digestion is an incredibly demanding task. When it occurs, all hands are on deck. When it isn’t required, hands can be diverted to other tasks. What Does the Science Say? Most of the data is looking at fasting in rats, mice, monkeys, and humans. But we do have some data from dogs. Fasting has been seen to decrease toxic load. With little competition from substances absorbed after a meal, the liver is able to fully process waste products and excrete them efficiently. In addition, it has been demonstrated that during fasting, mitochondria downregulate. As you’ll remember, the mitochondria are the power plants of the cell, where we get energy from. But through the process, a high volume of free radicals are produced. Therefore, with downregulation, fewer free radicals are produced, which reduces oxidative stress. Fasting has been seen to decrease inflammatory molecules in many cell types. As we know inflammation underlies many chronic diseases and so it’s easy to agree when we see data suggesting that fasting reduces the incidence of: Cancer Arthritis Cognitive decline Diabetes (prevention) Dermatitis Liver, kidney, and heart disease Findings Here Findings Here Furthermore, fasting has showed a lower rate of muscle loss with age, with no apparent loss of bone density. Findings Here Finally, fasting for 48 hours has been shown to protect normal cells, but not cancer cells, from the toxic effects of chemotherapy. This approach has been utilised in humans to mitigate side effects associated with chemotherapy. Findings Here So, we know that fasting has some great benefits, but is there anything we should be mindful of? Well, we shouldn’t fast cats, in it’s true definition. The feline liver doesn’t downregulate during fasting, hepatic lipidosis (fatty liver disease) has been seen to occur in a cat fasted for as little as two days. But calorie restriction (to 70% of a standard diet) has been used in therapeutic approaches and favourably affected physical activity, lipid metabolism and insulin sensitivity. Findings Here There’s also no place for fasting in puppies. Puppyhood is one of the most nutritionally demanding periods; to build a body, they need the component parts. The same goes for bitches in whelp; to build babies, they need the component parts. A note on diabetes… Diabetes is a disease that results from an absolute or relative lack of insulin. As we know, insulin helps get glucose into cells to be used as energy; it therefore maintains the amount of glucose found in the bloodstream. Fasting with diabetes can result in dangerously low blood sugar levels. The bottom line? Guidance from a qualified practitioner may be worthwhile if you are considering fasting with any pre-existing health concerns. It may not be appropriate at all. So How Do You Do It? Well, there are two ways really. The first is to fast for a whole day once a week. This was seemingly the accepted routine for farmers and gundogs in decades gone by. But it’s not about removing what your dog would usually eat on that day, you simply spread it out on the other days – some have spread it throughout the week, some load it the day before and the day after the fast. Ensure that the amount you are feeding is appropriate for the healthy weight your pet requires. The other way is just providing an eating window. You can feed one meal per day, or two but within a short eating window of each other (generally 6-8 hours of each other). For example, you feed breakfast at 9am and then supper at 4 or 5pm. During any fasting periods, dogs should always have access to fresh, filtered water. As you have noticed, there is a difference between fasting and calorie restriction – fasting is allowing periods of rest between food ingestion. Calorie restriction is reduction of calories. But both have great health benefits, depending on the pet and their current health status. If you are looking to tackle a weight issue in your pet check out our blogs here. Obesity in Pets – Part I Obesity in Pets – Part II Fasting or calorie restriction may not be appropriate for all pets, and so if you are wondering if any dietary changes may be of benefit to your pet, check out our services. Consultations Thanks for reading, MPN Team x
Would you be surprised to know that a study carried out in 1988 concluded there were no differences in allergens found on different breeds of dogs? In short, if you’re allergic to dogs, you’re allergic to all dogs? Findings Here Have we moved on significantly from 1988 and produced dogs that we’re no longer allergic to? We have artificial intelligence which can remind us of our daily schedule, but surely, a new type of dog, that’s pushing it? You’re correct. We’ve not produced a new type of dog (in that sense), if you’re allergic to dogs. You’re allergic to dogs. So, where does this notion of a hypoallergenic dog come from? They do exist, but in their true definition. Hypo means under or beneath according to the Greeks. Its synonyms include fewer, or less. Therefore, a hypoallergenic dog simply means a dog that is less likely to cause a reaction. It does not mean the dog is totally allergy safe. Where the confusion lies, is that many think allergy sufferers are allergic to the hair found on the dog. This is not the case. Generally, allergy sufferers are allergic to a protein found in the saliva and urine of the dog. As the dog grooms themselves, they spread the protein to their skin and coat. As new skin cells are produced, old ones are shed, which release into the environment (known as dander). This is why people are often told they are allergic to dog dander. As hair is shed into the environment, you are exposed to the protein covered hair. So, a hypoallergenic dog is generally one that sheds less (less hair for you to be exposed to), they often have curly coats (which traps hair and dander so less is shed into the environment) or have less hair (but these guys still lose dead skin cells which can cause a reaction). They are also more likely to be regularly groomed which removes the protein from the coat and skin more frequently. For many of us who have mild allergies, we tend to put up and shut up simply because we couldn’t imagine spending our lives without pets, so is there anything we can do to reduce our symptoms? You’ll know that here at My Pet Nutritionist we’re not a fan of long-term use of antihistamines, so let’s look at other options. 1) Find a new love for cleaning! Whilst it can often be the last thing you want to do at the end of a long day, getting into a habit of regularly whipping around your home will keep allergens in the environment at bay! If you don’t want to tackle the whole house as soon as you get in, create a to-do list at the beginning of the week. You may tackle your kitchen on Monday, your hall on Tuesday, your bedroom on Wednesday and so on. Rather than dusting, use a damp cloth or use the dusting attachment on your vacuum. You want to remove the allergens not just move them around or throw them back into the air that you are breathing. Set a timer on your phone or clock, spend 25 minutes a day cleaning. That’s 1.74% of your day. 2) Use a Vacuum with a HEPA filter! To keep allergens at bay, vacuum at least 2-3 times a week, if not daily. HEPA means high efficiency particulate air and its design traps microscopic particles keeping them from being thrown back into the environment. Most pet vacuums have an inbuilt HEPA filter but it’s worth checking the label if you’re in the market for a new one! 3) And an air purifier! It may be worthwhile investing in an air purifier in your home. Again, these are built with HEPA filters which trap dust and dirt. They can be a helpful addition to your home if you are struggling with your symptoms. 4) Pay attention to your bedding! If your dog sleeps with you, first decide whether this is great for your symptoms. If it doesn’t affect you too severely, ensure you wash your bedding at least weekly. Place blankets or throws on your bed so you can wash them even more regularly. Encase pillows and mattress with dust-proof covers as this helps keep particles from getting inside. Vacuum your mattress regularly. 5) Curtains! Be mindful of the curtains you are hanging in your home. Whilst you can purchase some beautiful fabrics, some are dry clean only. This isn’t ideal if you need to be washing them regularly – it’ll cost a fortune! Cotton curtains can often just be washed in the washing machine and hung to dry. Just like the response in our dogs, allergies result in a characteristic pattern of inflammation, so ensuring out own inflammatory responses are appropriate is just as important. Risk Factors in Human Allergies: Family history – predispositions to certain allergies, Microbiome disruption, Ultra-hygienic environment, Regular consumption of high-histamine foods, Nutrient deficiencies, Exposure to environmental toxins, Impaired methylation affects histamine clearance and more. Top Tips to Support Allergies in Humans: Live bacteria supplementation may support immune function, Consider histamine exposure in diet, Quercetin possesses anti-inflammatory and antihistamine properties, Nettle too functions as an antihistamine and blocks proinflammatory cytokines, Vitamin C supports histamine detoxification, Reduce stress! Gut Guardian A slightly different blog this time, but one we hope was useful, nonetheless. If your dog is sadly the one who suffers with sensitivities or allergies, then check out our blogs: 5 Basic Tips For Allergies Itchy Cats and Dogs Naturally Itching Has Become Such An Epidemic Does My Dog Need An Allergy Test In addition, allergies are one of our expert areas, so check out our services here: Consultations Thanks for reading, Team MPN x
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
Histamine intolerance (HIT), more technically known as enteral histaminosis, is characterised by the development of problematic symptoms after the ingestion of histamine containing foods. However, current schools of thought are that HIT is not solely due to dietary histamine exposure, but exposure along with insufficient or impaired histamine detoxification. We can see the raised eyebrows from here, so here at My Pet Nutritionist, we thought we’d take a closer look at this issue. 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. It is primarily associated with the functioning of the immune system. During an immune reaction, histamine is released from mast cells throughout the body and contributes to the physical changes necessary for the immune system to fight the pathogen, like the increase in blood pressure, temperature, swelling, and constriction in the lungs. Histamine is released to carry out a function and then it is removed, or it should be, efficiently. Detoxification of dietary histamine normally occurs in intestinal epithelial cells via the enzyme diamine oxidase (DAO) as well as histamine-N-methyl-transferase (HNMT) in the liver. The term histamine intolerance is used similarly to lactose intolerance in humans (LIT). LIT, with a deficiency of the enzyme lactase, shows parallels to the definition of HIT, with a deficiency of the GI enzyme diamine oxidase (DAO). DAO is a secretory protein stored in structures of the plasma membrane and is responsible for the degradation of extracellular histamine. The expression of DAO is restricted to certain tissues, mainly the small intestine, colon, placenta and kidneys. In the intestine, DAO activity increases progressively from the duodenum to the ileum and is located mainly in the intestinal villi. On the other hand, the enzyme HNMT is expressed in a wide range tissues including the kidneys and liver, the spleen, colon, prostate, ovaries, spinal cord cells, trachea, and respiratory tract. The gateway for dietary histamine is the intestinal epithelium. So, although HNMT is also present in the gastrointestinal tract, the more highly expressed DAO plays the major role in protecting the body against exogenous histamine, whether originating from ingested food or generated by the intestinal microbiota. What Can Cause Deficiencies in DAO? There are polymorphisms in the genes that encode for the DAO enzyme, but certain medications, including over the counter products are seen to inhibit the activity of DAO enzyme too. They include: Analgesics – morphine, NSAIDs Antiarrhythmics Antibiotics Antifungals Antimalarial Diuretics Motility agents Muscle relaxants Vitamins – ascorbic acid, thiamine Findings Here Furthermore, several inflammatory bowel pathologies affecting mucosal integrity are known to result in impaired DAO activity. DAO activity has been proposed as a marker of the integrity of intestinal mucosa. In inflammatory bowel diseases, reduced DAO activity was related to the degree of mucosal damage. In one human study, DAO activity was significantly reduced in cases of ulcerative colitis compared to the control population. gut guardian can help support histamine intolerance and allergies. Findings Here Gut Guardian Prevalence of DAO deficiency in HIT In human studies, 80% of patients showing symptoms of HIT also demonstrated DAO deficiency. Symptoms of HIT include: urticaria pruritus diarrhoea abdominal pain vomiting constipation cough rhinitis If DAO production is low, histamine blood serum will inevitably be high. This is where the liver needs to be functioning effeciently, to assist with excess histamine metabolism. Liver Guard Diagnosing HIT Currently the general rule of thumb is that two or more symptoms of HIT are being presented. Other gastrointestinal pathologies should also be dismissed. Low histamine diets are recommended in the short term, to establish remission or improvement in symptoms. Low Histamine Diets Foods that potentially contain high levels of histamine are: a) those microbiologically altered, such as fish and meat, or derived products that may have been preserved or processed in unsuitably hygienic conditions. b) fermented products, in which the bacteria responsible for the fermentation process may also have aminogenic capacity. If you would like more information on low histamine diets check out our blog here. Low Histamine Diets for Dogs More are now acknowledging the role of DAO inhibitor medications and the result on histamine load. In addition, we must consider how the health of the gut may be influencing enzyme capacity and so we really need to take a look at the bigger picture. Does My Pet Need to Detox 7 Steps to Optimal Gut Health for Pets If any of this is ringing a little true for your dog, then please check out our services to see if we may be able to help. Thanks for reading, Team MPN x
The microbiome was first defined in 1958. It was identified as the collective genome of the microorganisms that share body space. These microorganisms include bacteria, archaea, virus, and fungi. It is believed that 90% of human cells are not of human origin; hence the saying we are only 10% human. Microorganisms of the microbiome therefore provide an important genetic variation. Bacterial genes provide diversity and functions that human cells do not have. This similarly applies to our pets. The microbiome is an important modifier of disease and an essential component of immunity. Dysbiosis of the many microbiomes have been associated with a range of disorders and each day we are learning more about more about the community inside and on top of us, and our pets. Whilst our research is still getting a handle on things, and there are many things we still don’t know much about, we know that certain things can skew the microbiome to result in dysbiosis, and there are somethings than can help it sort itself out. Let’s take a look. The intestinal microbiota is the collection of all microorganisms in the gastrointestinal tract. The microbiome is the collective genome of these microorganisms. Bacteria make up most microbial cells, showing an increase in abundance from the stomach to the colon. The predominant phyla in the GIT of healthy dogs are: Firmicutes, Bacteroidetes, Actinobacteria, and Fusobacteria But each individual animal will have their own personal profile. A note on testing… it would stand to reason, that if we know the bugs that contribute to healthy microbiomes and those that can start to run amok, if we could test for them, then we could tailor a microbiome for health? This is a great concept and one that is gaining traction in the human world, but we still haven’t established a perfect microbiome or microbiota. As it stands, we need to learn more – and acknowledge that our microbiomes are unique – what may be perfect for your dog, may not be perfect for mine. We know that certain bacterial groups have consequences – both beneficial and potentially deleterious. For example, certain dietary carbohydrates can be fermented by the microbes in the gut – in this process, they produce short-chain-fatty-acids. These are known as butyrate, acetate and propionate. On the plus side, these compounds are anti-inflammatory, they maintain intestinal barrier function, regulate motility (the movement of the digestive system) and also provide energy for epithelial cells. On the downside, they can activate virulence factors of enteropathogens. In addition, bile acids also seem to be a major regulator of the gut microbiota. Liver health is therefore implicated in microbiome composition as reduced bile levels are associated with bacterial overgrowth and inflammation. Secondary bile acids have been seen to inhibit the growth of clostridum difficile, Escherichia coli and more. They are also seen to modulate glucose/insulin secretion from the pancreas. Bacteria in the gut produce these secondary bile acids and so if they aren’t present, their antimicrobial function is missed! Dogs with exocrine pancreatic insufficiency have significantly reduced bacterial diversity, with lactic acid bacteria Bifidobacteriaceae, Enterococcaceae, and Lactobacillaceae increased, likely because of overgrowth associated with maldigestion. As we know, the pancreas produces enzymes that help digestion, so if this isn’t occurring upstream in the digestive process, it can cause problems further down. If you would like to know more about the digestive process that occurs in the dog, check out our blog: The Digestive System of the Dog Many studies have highlighted the alterations in bacterial diversity in a range of conditions in the dog. So, what can result in these alterations in bacterial diversity? Generally, the major types of dysbiosis fall under 4 categories. Abnormal substrates in digestive tract Loss of beneficial commensal bacteria Increase in total bacterial load Increased pathogenic bacteria Abnormal Substrates in Digestive Tract The most common here are undigested nutrients – if there is low stomach acid, digestion is impaired resulting in undigested nutrients moving through the digestive tract. If the pancreas isn’t fully functioning and releasing those helpful digestive enzymes, the same applies. The other abnormal substrate includes medications – which may result in changes in the microbiome. Loss of Beneficial Commensal Bacteria The most common cause of loss of commensal bacteria is the administration of broad-spectrum antibiotics (BSA) – BSAs aren’t fussy – they’ll do their job perfectly, taking all bugs with them – this includes those beneficial commensal bacteria that keep the bad guys in check, and which help produce metabolites for optimal functioning. Of interest here is the mechanism by which antibiotics can affect the chemical transformation of pesticides. Antibiotics, through their bug killing capacity, have been seen to suppress enzymes required in hepatic metabolism and also increase intestinal absorption leading to improved bioavailability of pesticides and therefore skyrocketing their risk factor. Findings Here Increase in Total Bacterial Load This is more relevant in cases of small intestinal bacterial overgrowth. 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. For this reason, 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. Low stomach acid can contribute to the development of SIBO – and the administration of proton pump inhibitors and antihistamines can both suppress gastric acid secretion. Poor motility can also contribute to the development of SIBO, and stress can be a huge factor that contributes to motility issues. In short, if the digestive system isn’t moving, food particles sit where they shouldn’t. Increased bacterial load is what occurs in yeast issues for example. Candida is harmless when kept in check, but for a number of reasons it can overgrow. If you would like to learn more about yeast, check out our blog: Is your Dog a Yeasty Beast? Increased Pathogenic Bacteria No-one will knowingly ingest pathogenic bacteria – we can’t speak for
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
