Fibre is a super important addition to your dog’s diet for a range of reasons, but where can we get it from? We’ve popped together 7 of our favourite foods to add to the bowl! Let’s get cracking. What is Fibre? Fibre is a non-digestible carbohydrate and it boasts a range of health benefits, for us, and our dogs. As fibre makes its way through the digestive tract, it can slow glucose absorption, which helps modulate blood sugar levels. It can also form a gel like substance which can trap potentially harmful pathogens. Fermentable fibres produce short chain fatty acids which have unique roles throughout the body. Not only do they contribute to maintaining a healthy gut barrier, but they are also precursors to many neurotransmitters, which directly affect mood and behaviour. Fibre is seen to modulate insulin production, blood pressure and thought to affect cholesterol and fatty acid absorption too. And last but not least, fibre can be a great way to modulate transit time in the gut too. Diarrhoea often results when transit time is too fast. Constipation often results when transit time is too slow. The perfect stool is a result of “just right” transit time. In addition, when this occurs, we support healthy anal gland expression. For a full expression, the faeces should be firm, and pick-up-able. This is why poor bowel movements can contribute to anal glands becoming impacted. 3 Top Tips for Anal Gland Health in Dogs Although fibre is generally an umbrella term, there are fibres within fibres, and we often hear more about the supplemental fibres when we are talking about our canine companions. Psyllium husk: Psyllium husk is a form of soluble fibre, it contains mucilage which swells when in contact with fluid, forming a gel. Psyllium can help to improve faecal consistency. Slippery Elm: An insoluble fibre with mucilage properties where it creates a film, soothes, protects, and helps to heal the entire gastric system, modulating gut function. The inner bark of the Slippery Elm is not only packed with nutrients like vitamins A, B complex, C, K, Calcium, magnesium, and sodium, but it also has anti-inflammatory properties. But we can get the benefits associated with fibre from a food first approach too! Fibrous Food Sources 1. Broccoli Not only is broccoli a great source of fibre but it is packed full of vitamins and minerals. You will find vitamins A, C and E, fibre and antioxidants in these little green trees! Vitamin A helps maintain structural and functional integrity of mucosal cells in innate barriers (skin, respiratory tract etc). Broccoli also contains a phytochemical called Indole-3-Carbinol. This compound is formed from a substance called glucobrassicin found in broccoli and other brasscia vegetables such as brussels sprouts, cabbage, collards, cauliflower, kale, mustard greens and turnips. Indole-3-carbinol is formed when these vegetables are cut, chewed, or lightly cooked and show some promise in their anti-cancer effect. To Serve: chop and lightly steam or blend. 2. Berries We generally love berries because they contain anthocyanins (Greek anthos =flower and kyáneos = blue). Many studies have linked these compounds with antioxidant, anti‐inflammatory, and anti-carcinogenic properties, along with protection against both heart disease and cancer, as well as a reduction in the risk of diabetes and cognitive function disorders. In addition, they have also demonstrated antimicrobial properties, specifically in cranberries and blueberries. But berries also pack a fair punch in terms of fibre content. Great berries to include are raspberries, blueberries, and cranberries. 3. Apples Another snack or training treat, apples pack a fair fibre punch! Chop into slices, just remember to avoid the seeds. Apples contain a range of antioxidants meaning they can help protect against oxidative stress. Apples are also a source of vitamin C and potassium. 4. Mushrooms There are literally thousands of species of mushrooms on the planet, so it can be a challenge to know where to start. But they are incredible in terms of the benefits they can provide. Mushrooms can be involved in the prevention of certain disease, the regeneration of damaged cells, the protection of tissues and cells and used during treatment of existing conditions. The bioactive compounds of mushrooms include polysaccharides, proteins, fats, ash, glycosides, alkaloids, volatile oils, tocopherols, phenolics, flavonoids, carotenoids, folates, ascorbic acid enzymes, and organic acids. Reishi mushrooms are adored for their immunomodulating benefits. Maiitike mushrooms have been used for their antibacterial function and cordyceps have been seen to inhibit inflammatory responses throughout the body. Mushrooms have been seen to be: Anti-inflammatory Anti-microbial Antioxidant Prebiotic Anti-diabetic And they are a great source of fibre for our dogs. If you are looking to add mushrooms to the bowl, cook them fully, lightly sauteed is fine. 5. Leafy greens Green leafy vegetables include spinach, kale, watercress and broccoli. In green leafy vegetables you will find vitamins A, C, E and K along with many of the B-vitamins. These vegetables also contain carotenoids. Carotenoids act as an antioxidant, deactivating free-radicals and limiting the damage they can cause. There are two broad classifications of carotenoids: carotenes and xanthophylls. The latter containing oxygen, whilst the former do not. Xanthophylls include lutein and zeaxanthin, which are both primarily associated with eye health. Beta-carotene one of the carotenes is turned into Vitamin A and is found in those green leafy veg like spinach and kale. Vitamin A is important in maintaining healthy skin, mucous membranes and supporting a functioning immune system. Green leafy vegetables also contain a rich source of folate, this is after all, where the name came from. Folate functions as a coenzyme in many processes in the body, it helps tissues grow and makes cells work. Folate is also involved in neurotransmitter synthesis, so it is implicated in mood and subsequently behaviour. To Serve: Lightly steam your kale or spinach, or blitz it up in a blender, pop it in a freezer mould and add them to your dog’s bowl! 6. Carrots You’ll notice the fibre content if you’ve ever fed these to your dog
Sadly, anal gland issues are quite prevalent in the general dog population and this can end up with owners asking groomers or vets to express them on a regular basis. The issue here is that anal gland expression has become the norm rather than the exception; and it really shouldn’t be. So, let’s take a look at the function of the anal glands and some of our top tips to promote anal gland health in the dog. What are the anal glands? The anal gland’s function is to release pheromones, enabling the communication between dogs and other mammals, including cats. The anal glands located on the lower sides of the anus, produce a fluid with a scent that identifies him or her, communicating sex, health, and approximate age to other animals. Healthy dogs display a huge variation in the appearance of their anal sac fluid; it can vary from yellow to brown and the consistency from watery to mucous to doughy. The secretion contains mucin rich in sialic acid and other anti-microbial proteins, namely lysozyme, immunoglobulin A and lactoferrin. As faeces is passed, the anal glands are expressed and so the fluid is secreted. But like all things in the body, sometimes this process goes a little wrong. The three main issues that arise with anal gland function include: impaction inflammation, and abscessation An anal sac impaction is characterized as an enlargement of the sacs due to retention of anal sac content, without showing any signs of inflammation except for pain and discomfort. Anal sac impaction can occur unilaterally, but most often it presents itself as bilateral. Anal sac inflammation, also called anal sacculitis, is defined as an enlargement combined with inflammation of the anal sac. The anal sac and perianal region often become red, swollen, and painful. In the case of an anal sac abscess, pyrexia (raised body temperature) is often present; however, pyrexia can also occur in the case of severe anal sac inflammation. An inflamed and often alopecic area of the anal sacs can be observed in the case of an anal sac abscess, again accompanied with swelling and pain. Discharge contaminated with blood can also occur. If your dog is suffering with their anal glands, you may notice the following: Scooting (dragging bottom on the floor) Licking or biting at the anus, Difficulty sitting or standing On rare occasion, chasing the tail. Predisposing Factors Anal sac disease is reported to occur more often in adult dogs and cats compared to puppies and kittens, Obesity may be a predisposing factor. Perianal fat can lead to compression of the anal sac ducts, resulting in retention of anal sac content. Anal sac disease in dogs seems to be more prevalent in spring/summer, Adverse food reactions or food allergies and atopic dermatitis are conditions mentioned as being associated with anal sac disease, There appears to be a relationship between the presence of diarrhoea and the occurrence of anal sac disease in dogs. 5 Reasons Why Your Dog May have Diarrhoea Sadly, there also appears to be around a 40% relapse rate for those dogs who suffer with anal gland disease. In dogs, recurrence of anal sac impaction and inflammation occurs on average after 4–5 months; for abscessation, the mean recurrence time is reported to be 10 months on average. Findings Here So, how can we avoid these issues, and certainly, if your dog has suffered anal gland issues, how can we avoid a relapse? 1) Support Healthy Immune Function The correlation between anal gland disease and food sensitivities and atopic dermatitis may suggest dysfunctional immune responses. It’s important to modulate inflammatory responses in the body and support a healthy immune system. It would be wise to embark on an elimination diet to establish any food sensitivities and optimise gut health. Elimination Diets For Dogs 7 Steps to Optimal Gut Health for Pets 2) Create a Healthy Gut Environment As the gut influences every function in the body, it makes sense to support its ecosystem as much as possible. Things that can contribute to a less than happy gut: Antibiotics Overuse of certain medications like proton pump inhibitors and antihistamines Poor liver function Poor motility Digestive disorders Poor pancreatic function Inflammation in the gut Stress Environmental toxins Dietary choices If you’d like to learn more about managing these for your dog, check out our blog here: What Can Help Gut Dysbiosis? 3) Feed a Wholefood Fresh Diet But you knew this one, didn’t you? When we feed foods that the digestive system can digest and utilise, everything moves as it should. Wholefoods offer roughage to the diet, helping elimination processes. Stools are better formed and so, as they pass, they express the anal glands. There has been data which indicated a meat only diet exacerbated anal gland issues, so remember if you do feed fresh, add some raw bones to the mix. If this is something you are unsure of, then please get in touch with us and we can help. Dietary fibre is also excellent at ‘moderating’ the transit time of food in the digestive tract. When this transit time is too fast (diarrhoea), fibre can slow digestion down and where it is too slow (constipation), it can help speed it up. Fibre can adapt beautifully and for this, a variation of vegetables and slippery elm is great. Slippery elm is a wonderful addition to your cat or dog’s diet, if they are having consistent anal gland problems. Slippery elm, also known as the red elm, is a native tree to North America. People use the inner bark for many different health concerns. It is a mucilage and as such, creates a layer around the mucous membrane of the digestive tract, soothing and healing the gut mucosa. If you would like some more pointers on supporting healthy anal gland function, check out our blog here: 4 Cornerstones for Healthy Anal Glands and if you would like some support with your dog’s health, then check out our services to see
Phytochemicals, also sometimes referred to as phytonutrients or polyphenols are biologically active compounds of plant origin. They are actually a plant’s natural defence. Normally, the properties are activated by damage to the plant which prevent insects and pests from eating them. A huge number of phytochemicals have been identified (8000+) and they are broadly classified as carotenoids and polyphenols but there are many further subdivisions. The question on everyone’s tongue, does my dog need them? Let’s take a look. Phytochemicals We are just starting to notice the health benefits of phytochemicals; buthey have been seen to: Protect DNA from damage Act as antioxidants Regulate hormonal function Support immune function Possess antimicrobial properties Phytochemicals and Inflammation Inflammation is the first biological response of the immune system to infection, injury or irritation. It is a necessary process, but it can sometimes get a little out of hand. This is where phytochemicals come in. Types of phytochemicals known as phenolics, and triterpenoids show high anti-inflammatory activity. These compounds are found in various fruits and vegetables. Findings Here Phenolic compounds are also seen to have a range of other health benefits in the body. It is thought that polyphenols may modulate blood glucose levels. On study in humans found that those people eating higher quantities of polyphenol-rich foods were 57% less likely to develop type II diabetes in a 2–4-year period. Findings Here Polyphenols are seen to promote the growth of good bacteria in the gut, and also fend off the bad guys! Win win! It is also thought that polyphenols may help probiotics survive and thrive too! Findings Here They have also been associated with: Delaying age-related cognitive decline Modulating inflammation in the brain Counteracting neurotoxins Protecting neurons against oxidative stress Enhanced memory and learning Findings Here Finally, researchers have found that certain polyphenols can modulate gene expression in cases of atopic dermatitis in dogs. In short, the researchers managed to control the inflammatory response in dermatologic disease. Findings Here They used extracts of luteolin which is found in foods like broccoli, carrots, peppers, cabbage and apple skins along with extracts of stilbene which occurs in some berries like blueberries. Other phytochemicals include sulforaphane and anthocyanins. Sulforaphane is an isothiocyante stored mainly inside cruciferous veggies, like broccoli. A great sulforaphane hack is to sprout your own broccoli seeds as these have way more sulphoraphane as the final plant. This compound has been seen to have anticancer properties in test tube studies, it is thought to release antioxidant and detoxification enzymes that protect against carcinogens. Sulforaphane is thought to support hearth health by reducing inflammation and also may reduce blood pressure. In addition, this compound has been seen to improve recovery and reduce mental decline after traumatic brain injury. Finally, sulforaphane has improved symptoms of constipation in humans in a 4-week study. Findings Here Anthocyanins (red, purple, and/or blue plant pigments) are found in many fruits but are thought to prevent the adhesion of pathogens to cell walls. When compared to other berries, the photochemical bioavailability was much higher in cranberries as compared to others, which is why it is thought to prevent adhesion of pathogenic bacteria in the urinary tract. Other Foods Which Contain Phytochemicals: 1) Pomegranate Pomegranate has been seen to help protect cells, especially those heart cells. Oxidative damage may be one of the contributors to heart failure in our canine companions and pomegranate has been seen to protect against this. They contain molecules known as ellagitannins. Pomegranate ellagitannins are not absorbed intact into the blood stream but are hydrolysed to ellagic acid over several hours in the intestine. Ellagitannins are also metabolized into urolithins by gut flora, and it is these urolithin A’s that exert anti-inflammatory and antioxidant properties. Findings Here 2) Ginger Ginger is loved for its anti-inflammatory properties in cancer therapy. Inflammation, or rather pro-inflammatory cytokines contribute to carcinogenesis by influencing the survival, growth, mutation, proliferation, differentiation and movement of tumour cells. It is proposed that ginger has anti-inflammatory and therefore anticancer potential. Ginger contains active phenolic compounds such as gingerol, paradol and shogoall that have antioxidant, anticancer, anti-inflammatory and anti-angiogenesis properties. Ginger has demonstrated significant reductions in inflammatory signalling in cancer cases. Findings Here Not only that but in cases of liver cancer, it has induced apoptosis, inhibited formation, decreased expression and suppressed cell proliferation. In cases of pancreatic cancer it has downregulated signalling and cell survival indicators, inhibited expression, decreases metastasis, inhibited cell proliferation and induced apoptosis. Ginger has decreased incidence of colon tumours and it has been reported that intragastric treatment of ginger increases survival time. Findings Here Adjunct to other therapy, ginger has been seen to improve cellular immunity and decrease fatigue, pain and stress in cancer patients. It is also noted to reduce nausea. Ginger is widely used in traditional Chinese and Indian medicine, it is thought to stimulate digestion, absorption, relieve constipation and flatulence. In Chinese medicine it is thought to improve the flow of bodily fluids and is therefore used to stimulate blood circulation. The active compounds found reduce the formation of pro-inflammatory prostaglandins and thromboxane therefore lowering the clotting ability of the blood, it should therefore be used with caution alongside blood thinning medication. 3) Carrots Carotenoid-containing foods are often red, yellow or orange and this includes the trust carrot. Carotenoids are a class of phytonutrients and are found in the cells of a wide variety of plants, algae, and bacteria. They help plants absorb light energy for use in photosynthesis. They also have an important antioxidant function of deactivating free radicals which helps offset oxidative stress. Does My Dog Need Antioxidants? However, there is a number of factors that influence carotenoid’s bioavailability, absorption, breakdown, transport and storage. In a number of studies, thermal treatment was shown to increase carotenoid’s accessibility, due to the disruption of cell walls and bond loosening (read: cooked) Other factors, such as genes and nutritional status, gender, aging or infection, also determine carotenoid bioavailability. It is well-established that any disease with the abnormal
Sadly, at some point in our dog’s lives they may get poorly, or need an op. They may also just need periods of some additional TLC. Whilst the most nutritionally demanding phase post weaning is growth in puppies, recovery also has its own set of nutrient demands. We thought we’d take a closer look at the nutrient needs of recovering dogs. What is Recovery? Recovery generally takes the same form, no matter the trauma. If us or our dogs are exposed to an infection, our immune system springs to action to engulf and destroy the threat. The same occurs during trauma – in the case of a wound, immune cells rally to the damaged tissue to prevent any infection from taking hold and encourage growth factors to replace the damaged cells. This also applies in cases of planned operations – the body has experienced a trauma and so, it needs to repair and recover. But, our dogs also need to recover after physical activity – and this is even more important if we have a sporting/performing dog. Recovery Processes Immune cells need certain nutrients to do their jobs, and so when they are working overtime, they want to get paid for it. But a similar mechanism occurs during work. Not only do we have the energy needs of work, but damage can occur to muscles. At a low level, they repair, and come back stronger next time (this is the premise of training). But again, they need materials to rebuild and repair. We can think of the body like a bank account. It is always withdrawing through daily tasks. Providing we fuel it well; we remain in the black. During recovery and recuperation, it takes a little more, and if we don’t deposit enough, we end up in the red. Red signals poor recovery and this isn’t what we want for our canine companions. So, what do we need to do to stay in the black? Carbohydrates There is no physiological need proven for carbohydrates in the dog, however, they do possess a nutrient sparing effect. What this means is that if carbohydrates are utilised for energy, protein can be directed to what it does best – build and repair, and fat can stabilise membranes in those recovering cells! In their cooked form, carbohydrates can be an easily digested source of energy for the recovering dog. Complex carbohydrates like sweet potatoes are a great source of fibre, vitamin A, vitamin C, potassium, and B vitamins. Fibre is also a carbohydrate, albeit an indigestible one, and as we know fibre is your dog’s best friend for more reasons than one. 5 Reason’s Fibre is Your Dog’s Best Friend Protein Protein is of course top of the list for the recovering dog. Protein is from the Greek meaning “of prime importance” and it really is. The body is built from protein. Once it is ingested, it makes its way through the digestive system and the liver reassembles amino acids into other structures to be used throughout the body. We have: Antibody proteins – these bind to viruses and bacteria to protect the body, Enzyme proteins – enzymes carry out almost all the chemical reactions that occur in the body. They also assist in the formation of new molecules or cells. Messenger proteins – these include hormones that transmit signals throughout the body, coordinating biological processes between cells, tissues, and organs. Structural proteins – these provide structure and support for cells; they also allow the body to move. Transport/storage proteins – these proteins bind and carry atoms and small molecules within cells throughout the body. Genes are what tell amino acids what structure they will be, and therefore what function they will have. So, as you can see, when we’re asking the body to do a lot of these things, they need protein to do the job. Most foods contain either animal or plant cells and will therefore naturally contain protein. But the processing of foods may change the amounts and proportions of some amino acids; for example the Maillard reaction and the associated browning that occurs when foods are baked reduces the available amino acid lysine. The quality of the protein is also important and depends on the amino acids that are present. Proteins from animal sources have a higher biological value than proteins from plant sources. This is because the pattern of amino acids in animal cells is comparable. This difference has led to a concept of first-class and second-class proteins, for animal and plant foods, respectively. Even in human data, we are seeing that probiotic supplementation alongside plant-protein sources is necessary for optimal absorption and utilisation. For the canine, a fresh-food diet containing animal sources of protein will support recovery. Fat Fat is a necessary macronutrient for the dog – they have an improved capacity to utilise fat as energy compared to us humans, but essential fatty acids also play a role in the inflammatory response. Inflammation is necessary, it rallies immune cells to tackle the issue at hand, whether this is an invading virus or a wound that needs to heal, but it can become chronic, and this is where is it problematic. Like goldilocks, we need just enough inflammation. Fatty Acids and Inflammation In dogs, the body has a requirement for two distinct EFA families. The Omega-6 and Omega-3 series. Eicosanoids are products of the oxidation of the omega families; they are collectively known as prostaglandins, thromboxanes and leukotrienes. The number of eicosanoids synthesised depends on the availability and type of fatty acid found in cell membranes. Human studies have demonstrated that the supplementation EPA significantly alters the ratio of EPA (omega-3) to AA (omega-6) in cell membranes which has been beneficial in inflammatory conditions. In short, consumption of omega 3, replaces AA. The result is fewer AA derived eicosanoids and more EPA or GLA eicosanoids, and therefore managing the inflammatory response. The thing to note is the omega 6:3 ratio. In many commercial foods we note
Naturally occurring hypoadrenocorticism (Addison’s disease) is an uncommon illness, with estimates of its incidence ranging from 0.36% to 0.5%. The clinical syndrome occurs when at least 85% to 90% of the adrenocortical tissue is destroyed, resulting in deficiencies of mineralocorticoids and glucocorticoids. This all sounds quite complex, so what do we actually need to know about Addison’s Disease in Dogs? Let’s take a look. What is Hypoadrenocorticism? This is where the adrenal glands don’t produce enough cortisol and aldosterone. Aldosterone is the most important naturally occurring mineralocorticoid, while cortisol represents the most important glucocorticoid. Aldosterone has a specific and vital action in the body because it enhances sodium, potassium, and body water homeostasis. It plays an important role among the redundant systems that regulate renal handling of sodium. Aldosterone is the most important hormone affecting renal potassium excretion and its main target organ is the kidney, with lesser actions in the intestinal mucosa, salivary glands, and sweat glands. Cortisol affects almost every tissue in the body. It increases availability of all fuel substrates in the body, by mobilising glucose. Cortisol aids in maintaining blood pressure, water balance, and vascular volume, particularly in the canine species. It also increases vascular sensitivity to catecholamines. Cortisol helps to maintain vascular tone, vascular permeability, and endothelial integrity. Finally, it suppresses inflammatory responses and has catabolic effects on connective tissue, muscle, and bone. Hypoadrenocorticism can affect dogs of any age, but it tends to occur in young to middle-aged dogs. The age range of reported cases is 4 weeks to 16 years. It also seems to occur more commonly in females. Some of the symptoms of Addison’s Disease include: Panting Fatigue/weakness Reduced appetite Dehydration/excessive thirst/increased urination – due to the imbalance of sodium/potassium which leads to lack of water conservation by the kidneys Weight loss Slow heart rate Shaking Cool to touch Vomiting/diarrhoea Although any dog can develop Addison’s, there are certain breeds which are predisposed to it, including: Standard Poodle Bearded Collies Soft Coated Wheaten Terriers West Highland White Terriers Great Danes There are a few main causes of Addison’s Disease. As with Cushing’s disease, tumours are prevalent. It is also suggested that certain medications, toxins, and diseases prime the dog’s immune system to destroy its own adrenal gland. Dogs treated for Cushing’s disease can also develop Addison’s disease in response to the medications destroying too much of the adrenal tissue. The Lowdown on Cushing’s Disease in Dogs Secondary Addison’s disease can develop if a dog has been treated with long- term steroids for any reason and the medication is abruptly stopped. This is known as iatrogenic hypoadrenocorticism and is generally temporary. This suppression occurs because large doses of corticosteroids signal the hypothalamus and pituitary gland to stop producing the hormones that normally stimulate adrenal function. Adrenal Insufficiency Critical illness-related corticosteroid insufficiency (CIRCI) is also referred to as relative adrenal insufficiency and has been associated with severe illness, such as sepsis, septic shock, or trauma. The syndrome is typically transient, and adrenal function normalises following correction of the underlying condition. Clinical Presentation Clinical signs may appear episodic, or “waxing and waning” in 25% to 43% of cases. Most dogs with hypoadrenocorticism have chronic disease, although it may be an acute exacerbation that prompts veterinary evaluation. Acute exacerbation of chronic hypoadrenocorticism may result from stress such as boarding, grooming, lifestyle changes, moving, or even a trip to the veterinarian. Findings Here Treatment is generally lifelong, but lifestyle modifications alongside can be beneficial. If your dog has been diagnosed with Addison’s Disease and you would like to optimise their diet and lifestyle, then check out our services to see how we can help. Thanks for reading, MPN Team
As our pets eat their food, it passes from the stomach and into the small intestine. Whilst some of the digestive processes have already started, most of the chemical digestion that occurs in the small intestine relies on the activities of the pancreas, liver, and gallbladder. Let’s take a closer look at the function of the pancreas and its role in our pet’s digestion. What is the Pancreas? The pancreas is a gland found in the digestive system of our pet. It is made up of a head, a body and a pointy tail-like end. It is in the upper abdomen behind the stomach and carries out two main roles in the body: The pancreas produces: Enzymes that break down foods in the intestine Hormones that regulate blood sugar levels The pancreas is made up of small clusters of glandular epithelial cells. About 99% of these clusters constitute the exocrine portion of the organ. These cells secrete a mixture of fluid and digestive enzymes known as pancreatic juice. Pancreatic juice consists mostly of water, but it also contains some salts, sodium bicarbonate and several enzymes. The sodium bicarbonate gives the pancreatic juice a slight alkalinity that buffers the stomach acid in the chyme that has just arrived in the small intestine. It also stops the action of pepsin and creates the correct pH for the action of the digestive enzymes to function. The digestive juices that are made in the pancreas flow into the small intestine through a tube known as the pancreatic duct. In most bodies, this duct is joined by a similar duct coming from the gallbladder (the bile duct) before it reaches the small intestine. There is a circular muscle (sphincter) at the shared opening of the two ducts. This muscle controls the release of the digestive juices into the small intestine. The digestive juices usually only start working once they enter the small intestine. But if the pancreas is inflamed (pancreatitis), they already become active in the pancreas. This can start causing a range of issues. Digestive Enzymes Enzymes are biological molecules (typically proteins) that significantly speed up the rate of virtually all of the chemical reactions that take place within cells. When discussing the pancreas, there are three main types of enzymes: Lipases to break down fats Proteases to break down proteins Amylases to break down starch The remaining 1% of the clusters called pancreatic islets (islets of Langerhans) form the endocrine portion of the pancreas. These cells secrete the hormones glucagon, insulin and more. These hormones usually help to regulate blood glucose levels, stopping them from getting too high or too low. Glucose Regulation Glucose is a 6-carbon structure with the chemical formula C6H12O6. It is a source of energy for every organism in the world and is essential to fuel both aerobic and anaerobic cellular respiration. Glucose often enters the body in isometric forms such as galactose and fructose (monosaccharides), lactose and sucrose (disaccharides), or starch (polysaccharide). The body stores excess glucose as glycogen, which becomes liberated in times of fasting. Glucose is also derivable from products of fat and protein break-down through the process of gluconeogenesis. Once glucose is in the body, it travels through the blood and to energy-requiring tissues. There, glucose is broken down in a series of biochemical reactions releasing energy in the form of ATP. The ATP derived from these processes is used to fuel virtually every energy-requiring process in the body. As glucose is so important to life, it stands to reason that regulation of it is incredibly tight. And as we have noted, there are a number of hormones involved in this process. Hormones involved in Glucose Regulation Hormones Involved: Insulin is a peptide hormone. Insulin plays an important role to keep plasma glucose value within a relatively narrow range throughout the day. Insulin’s main actions are: (1) In the liver, insulin promotes glycolysis and storage of glucose as glycogen (glycogenesis), as well as conversion of glucose to triglycerides (2) In muscle, insulin promotes the uptake of glucose and its storage as glycogen (3) in adipose tissue, insulin promotes uptake of glucose and its conversion to triglycerides for storage Insulin lowers glucose levels. Glucagon: Glucagon acts exclusively on the liver to antagonise insulin effects on hepatocytes. It enhances glycogenolysis and gluconeogenesis. It also promotes oxidation of fat, which can lead to the formation of ketone bodies. Glucagon increases glucose levels. Levels of both insulin and glucagon vary depending on nutrient intake. The Fed State: The fed state occurs after a meal and is also known as the absorptive state. It is characterised by a high insulin to glucagon ratio. Anabolic metabolism dominates in the fed state largely to replenish fuel stores, this is achieved by glycogen synthesis, fatty acid synthesis and protein and amino acid metabolism. The Fasting State: The fasting state occurs between meals and ensures a maintenance of blood glucose level. This state is characterised by a low insulin to glucagon ratio. This low insulin to glucagon ratio overall promotes catabolism in comparison to the fed state. In this state the major pathways include gluconeogenesis, glycogenolysis, protein catabolism, lipolysis, and ketone body metabolism Endocrine cells secrete these respective hormones in response to external signals, such as nutrient intake or stress, via humoral, neural or hormonal signalling pathways. The Brain-Islet Axis The pancreas is highly innervated with both parasympathetic and sympathetic nerve fibres from the autonomic nervous system. At the same time, insulin receptors are widely distributed within the brain. In rat studies, lesions in various brain regions were shown to affect pancreatic hormone secretion. Norepinephrine also inhibits insulin secretion, which is an important aspect of the fight-or-flight response. Insulin release is stimulated by the cephalic phase, which is the period of anticipating a meal, to prepare the body to adequately respond to incoming nutrients. The Liver-Islet Axis The liver has a key role in glucose homeostasis by storing (glycogenesis) or releasing (glycogenolysis/gluconeogenesis) glucose. Liver Guard The Gut-Islet Axis The gut releases various
We call eggs a reference protein for good reason, they contain all essential amino acids. Eggs are a nutrient dense food, not only packed with protein but a range of micronutrients too. As we work with raw diets as well as cooked, one of the questions we are asked all the time is whether raw eggs are safe for dogs. So, let’s settle it once and for all. Eggs are high in quality protein, they contain healthy fats, vitamins, minerals, eye protecting antioxidants and various other nutrients; One whole, large raw egg contains protein: 6 grams fat: 5 grams magnesium: 6 mg calcium: 28 mg phosphorus: 99 mg potassium: 69 mg vitamin D: 41 IU One large egg also contains 147mg of choline which is the precursor to acetylcholine, a key player in nervous system function. Eggs are high in lutein and zeaxanthin which are antioxidants involved in eye health. Does Raw Egg Hinder Nutrient Absorption? Egg yolks provide a good dietary source of biotin and raw egg whites contain a protein called avidin. Avidin is known to bind to biotin in the small intestine, preventing its absorption. We first found this in rats in the early 1900s. When rats were fed egg-white protein containing avidin, the biotin was biologically unavailable. This resulted in a syndrome of dermatitis, hair loss, and neuromuscular dysfunction known as “egg-white injury.” What is Biotin? Biotin is an essential water-soluble vitamin. It is also known as vitamin B-7 or vitamin H, in which case the H stands for “Haar und Haut,” the German words for “hair and skin.” Biotin is necessary for the function of several enzymes known as carboxylases. These are part of important metabolic processes, such as the production of glucose and fatty acids. Specifically, biotin is involved in: Gluconeogenesis: This is the synthesis of glucose from sources other than carbohydrates, such as amino acids/ Biotin-containing enzymes help initiate this process. Fatty acid synthesis: Biotin assists enzymes that activate reactions that are important for the production of fatty acids. Amino acid breakdown: Biotin-containing enzymes are involved in the metabolism of several important amino acids, including leucine. Research has shown biotin deficiency will result in abnormal fatty acid metabolism, which may be responsible for the pathogenesis of dermatitis and alopecia. Interestingly, supplementation of biotin-deficient rats with omega-6 polyunsaturated acids prevented the development of dermatitis, which indicated that an abnormality in n-6 PUFA metabolism is involved in biotin deficiency-related dermatitis (and perhaps not completely laying the blame at biotin per se). Other schools of thought relating to biotin-deficiency alopecia is the role of the microbiota in the gut. Free biotin may influence the composition of the gut microbiota because biotin is necessary for the growth and survival of the microbiota. Biotin deficiency leads to gut dysbiosis and the overgrowth of Lactobacillus murinus, leading to the development of alopecia. This is further compounded with co-administration of antibiotics. Furthermore, vitamin B7 production appears to proceed in a cooperative manner among different intestinal bacteria; Bifidobacterium longum in the intestine produces pimelate, which is a precursor of vitamin B7 that enhances vitamin B7 production by other intestinal bacteria. Based on this data you would be forgiven for thinking that raw eggs are a poor dietary choice because of the potential to cause a biotin-deficiency, but is this accurate? We established a biotin-deficiency using rats. We must remember that rats have no dietary requirement for biotin because it is provided by intestinal microorganisms through coprophagy. To this end there are four ways to produce a biotin deficiency in rats fed a biotin-deficient diet. use germ free animals prevent coprophagy feed sulfa drugs feed raw egg whites To achieve a biotin deficiency state, 20% raw egg whites as the source of protein was fed. Findings Here Whilst our dogs may like eggs, its unlikely that 20% of their diet will consist of them. Salmonella Poisoning Raw and undercooked eggs may contain Salmonella, a type of bacteria. Salmonella contamination can happen in one of two ways: either directly during the formation of an egg inside the hen indirectly when Salmonella contaminates the outside of the egg and penetrates through the shell membrane Indirect contamination can happen during the production process, during handling, or during preparation. In commercial egg sales, pasteurisation is one method that is often employed to prevent the possibility of Salmonella contamination. This process uses a heating treatment to reduce the number of bacteria and other microorganisms in foods. But where you source your eggs from is a more obvious consideration to make here. A review of risk factors for Salmonella in laying hens revealed that overall evidence points to a lower occurrence in non-cage compared to cage systems. There is also conclusive evidence that an increased stocking density, larger farms and stress result in increased occurrence, persistence and spread of Salmonella in laying hen flock. Findings Here So, opt for free range and organic raised hens to source your eggs from to reduce the risk of bacterial contamination. The bottom line? Eggs are nutritious whether you opt for cooked or raw. There may be compromised nutrient absorption, but this only occurs when significant quantities are eaten. Moderation is key and opt for free range and organic wherever possible. And yes, the shells can be eaten too. Thanks for reading, MPN Team
When we talk about inflammation, we generally see it as something bad and something we need to get rid of. But like all things ours and our pet’s body does, it serves a purpose. Despite this, there is a difference between acute and chronic inflammation. So, let’s get to grips with the purpose of inflammation, what causes it and when it becomes problematic. We’ll also take a look at some nutrition tips to help modulate this response. What is Inflammation? Inflammation is part of the body’s defence mechanism. It is the process by which the immune system recognises and removes harmful and foreign stimuli and begins the healing process. The immune system senses something is wrong and sends its soldier immune cells to tackle the issue, which is why the hallmark signs of inflammation; heat, redness, swelling and pain occur. Inflammation can be either acute or chronic. Acute Inflammation Tissue damage due to trauma, microbial invasion, or noxious compounds can induce acute inflammation. It starts rapidly, becomes severe in a short time and symptoms may last for a few days, an example is bacterial infection. Chronic Inflammation Chronic inflammation is also referred to as slow, long-term inflammation lasting for prolonged periods of several months to years. Generally, the extent and effects of chronic inflammation vary with the cause of the injury and the ability of the body to repair and overcome the damage. For the most part, acute inflammation serves a purpose, and the issue is resolved. Chronic inflammation is what becomes the issue. Chronic inflammation can be a result of the following: Failure of eliminating the agent causing an acute inflammation like a recurrent infection or exposure to an allergen. Exposure to a low level of a particular irritant or foreign material that cannot be eliminated by enzymatic breakdown or phagocytosis in the body. An autoimmune disorder in which the immune system recognizes the normal component of the body as a foreign antigen and attacks healthy tissue. A defect in the cells responsible for mediating inflammation leading to persistent or recurrent inflammation. Inflammatory and biochemical inducers resulting in oxidative stress and mitochondrial dysfunction such as increased production of free radical molecules, advanced glycation end products (AGEs), uric acid (urate) crystals, oxidized lipoproteins, and homocysteine. Factors that may increase the risk of chronic inflammation include: Ageing Increasing age is associated with elevated levels of inflammatory markers – this could be due to mitochondrial dysfunction or free radical accumulation over time. Obesity Fat tissue is often described as an endocrine organ. It secretes multiple adipokines and inflammatory mediators. There is increasing data showing that the adiposity correlates with levels of pro- inflammatory markers. Diets high in saturated fats This is increased further in those who are obese. Low sex hormones Data has indicated that testosterone and oestrogen can suppress the production of pro-inflammatory markers – so when there are low levels (in the case of neutered pets) inflammation can increase. Findings Here Stress Physical and emotional stress is associated with inflammatory cytokine release – which is why the modulator of the stress response, cortisol is deemed anti-inflammatory. However, prolonged stress can result in cortisol dysfunction. It is thought that cortisol binding is downregulated, and it fails to function. In humans, stress-induced inflammation has been linked to a range of chronic conditions like osteoporosis, myopathy, sciatica and more. Findings Here Poor sleep/recovery Again, cortisol plays a role here. There is a natural diurnal cortisol in dogs. You will see a natural rise in cortisol in the morning, with it progressively dropping throughout the day. Dogs are similar to humans in this respect. If sleep is disrupted or our dogs are unable to follow their diurnal rhythms, cortisol levels can become dysfunctional. Study after study have highlighted that poor sleep is associated with higher levels of inflammatory biomarkers. Findings Here The Importance of Sleep Dietary sensitivities/allergens What goes on in the gut doesn’t always stay in the gut and translocation can occur across the gut wall. This means that particles end up in places they shouldn’t, calling the immune system to action. 7 steps to Optimal Gut Health in Pets Signs of Chronic Inflammation: Body pain Anxiety/depression Gastrointestinal issues like constipation, diarrhoea, and acid reflux Unintended weight gain/loss Frequent infections It is crucial to understand the driver of chronic inflammation, and assessment from a qualified practitioner will be necessary here. But in managing chronic inflammation there are some beneficial changes that can be made: Top Tips: limit intake of ultra-processed foods ensure an appropriate body weight Obesity in Pets Part One Part Two – high intake of dietary fibre is associated with lower inflammatory markers – increase intake of fruits and vegetables – blueberries, apples, brussels sprouts, and broccoli are all high in natural antioxidants and polyphenols which may help protect against inflammation. Does My Dog Need Antioxidants? – Curcumin – significant improvements are noted in inflammatory models in animals when administered turmeric. – Omega-3s – increased intake of omega-3 is associated with lower levels of many inflammatory markers. Essential Fats For My Dog’s Diet – Micronutrients – magnesium, vitamin D, vitamin E, zinc and selenium levels are all associated with inflammatory markers. They all exert inflammatory modulating effects in the body. The Importance of Vitamin D for Cats and Dogs Why Does My Dog Need Minerals? Why Zinc is Important for Your Dog Acute inflammation is necessary, and it is a process by which the body returns to homeostasis. The issue is when inflammation becomes chronic, and we know there are several reasons why this may occur. It’s essential to understand the contributing factors to chronic inflammation, but there are lifestyle changes that can help. Check out our services if you’d like to see how we can help. Thanks for reading, MPN Team
Epilepsy is the most common chronic neurological disorder in dogs, with a formerly reported prevalence of between 0.5% and 5% in the canine population. Epilepsy is not one single disease process but can be elicited by multiple causes and can be classified as genetic (primary or idiopathic), structural and of unknown origin/etiology. Let’s get to grips with what it is and some of the causes. What is Epilepsy? Epilepsy occurs naturally in many species including rodents, cats, dogs, horses, cattle, goats, non-human and human primates. It is the most common acquired chronic neurological disorder in humans having a a worldwide incidence of approximately 50–100 cases per 100,000 persons (higher in undeveloped countries) and a prevalence of 4–10 per 1000 persons. In humans there are over forty epileptic syndromes and related conditions. In dogs, however, epilepsy is not usually differentiated into syndromes. Most dogs with recurrent seizures have no identifiable underlying cause and are classified as having idiopathic epilepsy. The lack of canine epilepsy classification may be due to the difficulty of seizure description and classification, and partly because electroencephalography (EEG) is not routinely used in veterinary neurology clinics. To that end, we simply define epilepsy as a chronic neurological condition characterised by recurrent epileptic seizures. Idiopathic epilepsy in dogs Most dogs with recurrent seizures are thought to have idiopathic epilepsy, in short, no underlying cause of the seizure can be identified. In these cases the first seizure usually occurs between 6 months and 6 years of age, but occasionally seizures have been known to start as young as 3 months and as late as 10 years of age. There appears to be a hereditary basis for idiopathic epilepsy, with several breeds being affected: Beagles German Shepherds Labrador Retrievers Golden Retrievers Bernese Mountain Dog Viszlas Keeshonds English Springer Spaniel Recently a mutation found on the Epm2b gene has shown to be causal in miniature wire-haired dachshunds. The Theory of Epilepsy The pathophysiology of epilepsy is often suggested to be an imbalance between excitation and inhibition in neurotransmitters; increased excitation or decreased inhibition may lead to epileptiform activity in the brain. It is considered that there is a fine balance between the excitatory glutamate neurotransmitter and the inhibitory GABA neurotransmitter. This theory has been tested in dogs and researchers found significantly less GABA and more glutamate in cerebral spinal fluid (CSF) from epileptic patients when compared to normal controls. Sadly, there appears to be a double-edged sword too, many receptors in the brain undergo altered expression following seizures and this may lead to changes in excitability of the brain and be involved in further pathogenesis of seizure disorders. Temporal Lobe Epilepsy In Dogs Temporal lobe epilepsy is the most common partial seizure disorder in adult humans and there are reports of it occurring in dogs. It has also been suggested that “fly-biting” or “fly-catching”, a behaviour in which dogs snap aimlessly into the air as if trying to catch a fly, may have a temporal lobe origin. Treatment Since epilepsy is often associated with inhibition and excitation in the brain, antiepileptic drugs (AEDs) are used to alter the excitability of the brain and aim to reset the balance. There are many mechanisms thought to be involved in the action of antiepileptic drugs. They may functionally block voltage-gated sodium channels They may directly or indirectly enhance inhibitory GABAergic transmission They can inhibit excitatory glutamatergic neurotransmission They can modulate calcium ion channels Vagus Nerve Stimulation The method used in humans was devised in canine models and has since been used with mixed results. It is based on the idea that repetitive electrical stimulation of the canine cervical vagus nerve interrupts or abolishes motor seizures. Findings Here Epilepsy and Diet The Keto Diet The ketogenic diet—a high‐fat, low carbohydrate, and moderate protein protocol—has been used to treat epilepsy for nearly 100 years in both children and adults. A randomised controlled trial on childhood epilepsy showed promising results with 38 and 7 % of children on KD diets having >50 and 90 % seizure reduction, respectively. In comparison, only 6 % of the children on control diets achieved >50 % seizure reduction, with no children achieving >90 % seizure reduction. Findings Here It therefore makes sense that a ketogenic diet has been considered for use in dogs. One study of 21 dogs found that seizures were reduced significantly in dogs fed a proprietary ketogenic diet for 3 months. No improvement was seen in dogs fed a standard diet for the same duration. For 3 subjects, seizures appeared to stop entirely, demonstrating a 100% reduction in seizure frequency. In 7 dogs, seizures decreased by at least 50%, and another 5 dogs experienced a lower seizure frequency overall. Findings Here A Whistle Stop Tour of Keto A Keto Diet for Pet Cancer Omega-3 Supplementation Omega-3 fatty acid deficiency has an interesting role in seizure outcome. It is thought that Omega-3 fatty acids can enhance GABAergic transmission in animals with epilepsy by stimulating the formation of new hippocampal interneurons or by altering expression of calcium-binding proteins. When trialled in a patient with drug-resistant epilepsy, seizures reduced by 85%. Findings Here Essential Fats For My Dog’s Diet Epilepsy and Allergy In humans there are a number of reports that associate allergy with epilepsy. For example, children with allergic symptoms have a 76% increased subsequent risk of epilepsy. It has been found that in these individuals, hypoallergenic diets can reduce the frequency of seizures. Again, we must consider that this may apply to dogs. One study followed dogs with allergic disease. It included eight refractory epileptic dogs and seven were found to have gastrointestinal or skin allergies in conjunction with their refractory seizures. Introduction of an exclusion diet reduced seizures to an “acceptable level” in seven out of eight dogs. Behavioural abnormalities associated with seizures were eliminated in all cases. Findings Here Elimination Diets For Dogs Epileptogenic Toxins Many researchers posit that it’s not only certain foods that are epileptogenic, but toxins can also be problematic. Whilst we’re not talking
There are two branches of science that help us understand both ours and our pet’s bodies. Anatomy is the science of body structures and the relationships amongst them. We learned about anatomy through dissection – we carefully cut up body structures to see what they looked like and the relationship they had with those around them. Physiology is the science of body functions -in short how those body parts and structures work. Both branches have sub-branches, for example we may be interested in pathological anatomy – the structural changes associated with disease. In this blog, we are going to take a look at renal physiology – in short, the function of the kidneys. The Urinary System The kidneys form part of the urinary system and overall, this system consists of: Two kidneys Two ureters One urinary bladder One urethra As body cells carry out metabolic activities they consume oxygen and nutrients. During this process, waste products are made. These waste products must be eliminated from the body because if they are left to accumulate, they can become toxic. Just like the respiratory system eliminates carbon dioxide, the urinary system picks up these waste products. But this is not the only function of the urinary system. Functions of the Kidneys Excretion of wastes: By forming urine, the kidneys help excrete waste from the body. Some of these are a result of metabolic processes, like urea and ammonia, which is as a result of the deamination of amino acids, but it also includes creatinine which is a result of breaking down creatine phosphate. Finally, it includes uric acid from the catabolism of nucleic acids. These compounds are all known as nitrogenous wastes as they are wastes that contain nitrogen. The remainder of wastes are foreign substances that have entered the body, like medications and environmental toxins. This is why we look at kidney health when considering the toxins our dogs must break down. Does My Pet Need to Detox? Regulation of blood composition: The kidneys help regulate the blood levels of several ions including sodium, potassium, calcium, chloride, and phosphate. This is achieved by controlling the excretion of said ions into urine. Why Does My Dog Need Minerals? Regulation of blood pH: The kidneys excrete a variable amount of hydrogen ions into the urine and conserve bicarbonate ions which are an important buffer of hydrogen in the blood. Both of these activities help regulate blood pH. Regulation of blood volume: The kidneys adjust blood volume by conserving or eliminating water in the urine. An increase in blood volume increases blood pressure and a decrease in blood volume decreases blood pressure. Regulation of blood pressure: The kidneys secrete the enzyme renin which activates the renin-angiotensin-aldosterone pathway. Increased renin increases blood pressure. Production of hormones: The kidneys produce two hormones, calcitriol helps regulate calcium homeostasis and erythropoietin stimulates the production of red blood cells. Regulation of blood glucose level: Like the liver, the kidneys can use certain amino acids like glutamine in gluconeogenesis, which is the production of new glucose molecules. They can then release glucose into the blood to help maintain a normal blood glucose level. The Contributions of The Urinary System for All Body Systems Skeletal System The kidneys help adjust levels of blood calcium and phosphates needed for building extracellular bone matrix. Nutrition for Bone and Joint Health Muscular System The kidneys help adjust calcium levels for contraction of muscle. Nervous System Through the process of gluconeogenesis, the kidneys provide glucose for ATP production in neurons, especially during fasting or starvation. Endocrine System The kidneys participate in the synthesis of calcitriol, the active form of Vitamin D. They also release erythropoietin which is the hormone that stimulates the production of red blood cells. Cardiovascular System As noted previously, the kidneys play a key role in the regulation of blood volume, pressure, and composition. Lymphatic System and Immune Function By increasing or decreasing their reabsorption of water filtered from blood, kidneys help adjust volume of interstitial fluid and lymph. Urine also flushes microbes out of the urethra. Respiratory System The kidneys and lungs cooperate by adjusting pH of body fluids. When Should I be Worried About My Dog Panting? Digestive System As we have mentioned, the kidneys synthesise calcitriol which is the active form of vitamin D. This is necessary for the absorption of dietary calcium. Ageing and the Urinary System With ageing, kidneys do shrink in size; they have decreased blood flow and filter less blood. These age-related changes seem to be linked to a reduction in blood supply to the kidneys for example, with age, blood vessels such as the glomeruli become damaged or decrease in number. There is also a natural decrease in thirst drive with age which brings the added risk of dehydration. Urinary bladder changes include a reduction in size and capacity, along with a weakening of the muscles. This is why urinary tract infections, increased frequency of urination and urinary retention or incontinence becomes an issue with age. It would be easy to conclude that the kidneys main job is to excrete waste, but as you can see, the kidneys contribute to many other body system functions. In addition, they are not the only tissues, organs or systems that handle body wastes. Waste Handling Systems Blood The bloodstream provides a pick-up and delivery service for the transport of wastes, we can think of the bloodstream as our bin wagons. Liver The liver is the primary site for metabolic recycling. The liver rearranges amino acids into other proteins, and also converts them into glucose. The liver also converts toxic substances into less toxic ones. Lungs With each exhalation, the lungs excrete carbon dioxide, along with heat and a little water vapour. Gastrointestinal Tract Through defecation the gastrointestinal tract excretes waste, whether it is undigested foods or metabolic waste products. The kidneys play a number of roles in health, and therefore disease. If you would like to learn more about kidney function and some of our top
It can feel like we are bombarded with information to boost our immune function, and as immune system health is key to survival, this seems like something we should be interested in. We also talk about immune responses a lot here at My Pet Nutritionist, so should we be boosting our pet’s immune systems too? What if we told you that immune boosting isn’t really something we want to do? Read on to find out why we believe immune boosting is a myth. The Immune System When the body is invaded by bacteria, a virus or parasites, an immune alarm goes off, setting off a chain reaction of cellular activity in the immune system. Specific cells are deployed to help attack the invading pathogen. Those cells often do the job, and the invader is destroyed. But sometimes, when the body needs a more sophisticated attack, it turns to a more specialised set of cells. These cells are like the special ops of the immune system—a line of defence that uses past behaviours and interactions to tell it exactly how to deal with the threat. The immune system is responsible for all of this, and not surprisingly is has many systems to mobilise action. We tend to explore the immune system in terms of innate immunity and adaptive or acquired immunity. Innate immunity is what everyone is born with – it’s a type of general protection. Acquired (adaptive or specific) immunity is not present at birth. It is learned. It’s easy to consider the immune system as an “us against the germ” fight, it’s also easy to think of the immune system as binary. There are either threats, or there aren’t. But how do we figure out what aren’t threats? This is where the concept of immune tolerance comes in. Immune Tolerance Immune tolerance is an active state of unresponsiveness to specific antigens in an effort to prevent destructive over-reactivity of the immune system. It prevents an immune response to antigens produced by the body itself or recognised from a prior encounter. It’s Evolutionary Immune tolerance is an evolutionary benefit – mounting an immune response is resource demanding, and sometimes brings some collateral damage with it. If tolerating an antigen conserves resources and doesn’t result in overt threat or damage, then it makes biological sense to do so. There are two types of immune tolerance: self-tolerance and induced tolerance. Self-tolerance refers to the ability of the immune system to recognize and therefore not respond to self-produced antigens. If the immune system loses this ability, the body can start to attack its own cells, which may cause an autoimmune disease. Induced tolerance occurs when the immune system actively avoids responding to an external antigen. This tolerance is induced by previous encounters with that antigen. Immune tolerance mechanisms are separated into two categories: central tolerance and peripheral tolerance. Central tolerance occurs during lymphocyte development in the thymus and bone marrow. In short, if any developing T or B cells become reactive to self, they are eliminated. Peripheral tolerance mechanisms occur after mature lymphocytes are released into the lymph nodes or other tissues. When T cells that are reactive-to-self escape into the periphery, this mechanism ensures they are either deleted or they become functionally unresponsive to the antigen. The Immune System as A Seesaw We can think of the immune system as a seesaw and immune responses need to be balanced. Immune tolerance helps balance the seesaw as our pet’s make their way through life. It is different from non-specific immunosuppression and immunodeficiency. Immune tolerance prevents inflammatory reactions to many innocuous airborne and food allergens found at mucosal surfaces (and more). How is Immune Tolerance Developed? Immune tolerance is only induced via exposure to the antigen in question and it is thought that the timing of this exposure is crucial. This is where the hygiene hypothesis has been largely considered. The Hygiene Hypothesis Early exposure to a diverse range of “friendly” microbes—not infectious pathogens—is necessary to train the immune system to react appropriately. 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 effector 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, and so loss of tolerance, along with excessive tolerance can occur. Loss of Tolerance Loss of tolerance results in an overt immune response. This could be in the case of allergy, but also autoimmunity. T and B lymphocytes are key players for immune responses, and during the T and B lymphocyte differentiation process, the regulation of each progression step is influenced by a potent network of transcription factors specific for each cellular state. Recent studies indicate that both T and B lymphocyte development are under epigenetic regulations which suggests a genetic consideration in immune function, but that modifiable lifestyle changes could influence gene expression. Environmental factors, such as ultraviolet rays, infections, nutrition, and chemicals, also participate in the pathogenesis of both allergies and autoimmunity. Excessive Tolerance Excessive tolerance may lead to invasion by microorganisms or parasites, or to development of cancer. The Immunity Boosting Myth This idea of immune tolerance is in opposition to immune boosting. Ideally, we want an immune seesaw. We want responses to be balanced to whatever they are facing, not boosted and over-zealous and likewise, not lazy! We want an immune system that has 20/20 vision. So, how do we support this in our pets? Exposure to bugs – let
We often talk about the highway between the gut and the brain, but it is probably more appropriate to think of the gut like a roundabout. If you live anywhere other than the UK, a roundabout is a road junction at which traffic moves in one direction around a central island to reach one of the roads converging onto it. In short, you have a number of roads branching off. We are learning more about the gut’s impact on the body every day, and along with a gut-immune axis, (one road off the roundabout), the gut-brain axis (another road off the roundabout), we also have a gut-skin axis. The gut-skin axis is becoming intertwined in a range of inflammatory skin issues in humans, and as our dogs also sadly suffer with many inflammatory skin issues, here at My Pet Nutritionist, we think the Gut-Skin Axis is worth exploring. So, let’s get cracking. The Skin The skin is the largest organ of your dog’s body. It consists of three major layers: The Epidermis – (Epi – upon or above) this is the outer layer of skin, the protective layer. The Dermis – the dermis supports and nourishes the outer layer. It provides strength and elasticity. Here you will find collagen fibres, sweat glands, sebaceous glands, and hair follicles. You will also find cells that release histamine and other inflammatory mediators when faced with an allergy or injury. The Subcutis – (sub meaning under or below) this in the innermost layer of the skin, where you will find fat and muscles. Subcutaneous fat provides insulation, padding and storage for reserve energy. Not only does the structure of the skin prevent water and electrolyte loss to help maintain body homeostasis, but it forms a protective barrier which helps protect against infections, parasites, and the elements. This is the often-forgotten role of the skin – that it forms part of the immune system. It is this role that largely establishes the connection between the gut and skin. The Gut The gastrointestinal tract (GIT) is one of the largest interfaces between the host and its environment, you only have to think of the sheer volume of food and (and other items) that pass through your dog’s GIT in their lifetime. For this reason, it must posses a strong barrier to prevent pathogens reaching the inner workings of the body. Skin Vs. Gut Barrier The gut and skin barrier share surprisingly many features. Both organs are highly innervated and vascularized, as they are both essential for immune and neuroendocrine function. The inner surface of the gut and the outer surface of the skin are both covered by epithelial cells (ECs) which have direct contact with the exogenous environment. This way, the immune system is continuously primed to distinguish between harmful and beneficial compounds. Immune cell priming starts early on in life and forms the basis of tolerance. Your Pet’s Immune System But, both the skin and gut also posses a microbiome and it is this, along with the interplay between them that influences their health. How Does The Gut Affect The Skin? We have largely established the impact the gut has on skin through bacterial supplementation. Study One Mice who received Lactobacillus reuteri supplementation experienced increased dermal thickness, enhanced folliculogenesis, and increased sebocyte production which manifested as thicker, shinier fur. Findings Here Study Two Oral supplementation of Lactobacillus brevis SBC8803 in rats demonstrated a significant decrease in transepidermal water loss, which is a marker of skin barrier function. This was also replicated in humans. Findings Here Study Three Volunteers who took Lactobacillus paracasei NCC2461 supplements for 2 months had decreased skin sensitivity. Findings Here Study Four Another study evaluated the impact of Bifidobacterium breve M-16V and Bifidobacterium longum BB536 administration over the time period of 1 month prenatally, 6 months during infancy, and a period of 18 months follow up on the management of allergic diseases in humans. The study concluded that the incidence of atopic dermatitis was lower in the probiotic administered cases, compared to controls. Findings Here Whilst these studies are promising, there are equally studies which conclude no significant effect on inflammatory skin disease when supplementing probiotics. More and more data is appearing suggesting that clinical significance is largely strain specific, and some studies simply researched the wrong strain. Equally, we understand that inflammatory conditions are multifactorial, and there is no silver bullet. But what these studies do show us is that what goes on in the gut, can influence skin health. We have found that the metabolites found in the gut (those produced from the fermentation of fibre for example) have effects on the gut and the skin. SCFA’s are seen to have anti-inflammatory effects in the gut and in the skin. GABA metabolites modulate neurotransmitter function but also restrict itching in the skin. Dopamine modulates neurotransmitter function but also inhibits hair growth in the skin. Acetylcholine also modulates neurotransmitter function but also influences barrier function in the skin. This is also demonstrated when we look at dietary implications in skin conditions, for example, in cases of atopic dermatitis, diets are frequently low in fruits, vegetables, omega-3 fatty acids and high in omega-6 fatty acids. Findings Here But when we see the comorbidity of skin and gut issues, it’s easy to wonder which came first and what’s super interesting is that we see a bidirectionality. Studies have demonstrated that food allergies may result from an impaired skin barrier: atopic dermatitis sensitizes to peanut allergy due to epicutaneous peanut protein exposure in household dust, leading ultimately to immunoglobulin E (IgE)-mediated mast cell expansion in the gut. Findings Here Whether the gut or skin comes first, what is clear is that we need to support the health of both. The intestinal and epidermal barriers are connected through systemic circulation (blood and lymph), so healthy circulation is important. This is where appropriate exercise comes in. But avoid over-exercising as this ramps up the stress response in our pets and can be detrimental to the
