Any quick search on the internet will populate a range of breeds that are seemingly notorious for being fussy eaters. If you have a basenji, husky or yorkie, it looks like you’re signed up for a lifetime of stressful meals. Except here at My Pet Nutritionist, we don’t believe everything we read on the internet. Whilst all those breeds could indeed be fussy eaters, so can many more. And they are. It is perhaps one of the more common questions we are asked, “how can I get my dog to eat?” Being a fussy eater can be technically defined as an eating disorder, and there are a number of causes. From behavioural to biochemical, let’s take a look at the complex world of the fussy eater. The Function of Eating Food components are the main sources of energy for the canine body. Not only that, but it provides the compounds needed for each cell to do its job. As the body carries out its tasks, it uses fuel and compounds, as reserves run low, signals bounce around the body to kickstart feeding behaviour. This is hunger, a physical need to eat. Appetite is quite simply the desire to eat. Hunger and appetite can be at odds. You may want to eat, but not need to, and you may need to eat, but not want to (in times of stress for example). Appetite and hunger are largely controlled by the brain and a range of hormones. The Brain In the brain sits the hypothalamus. Through its connection to the pituitary gland, it modulates the endocrine system. It is involved in a range of daily activities including temperature regulation and energy maintenance. We know it plays a role in eating behaviour as several lesions to small areas of it can result in overeating and under eating. The lateral hypothalamus is defined as the feeding centre and the ventromedial hypothalamus is defined as the satiety centre. This is largely an oversimplification, but it certainly demonstrates the role. The hypothalamus receives information from the digestive system like stomach extension, chemical nature of ingested food and the metabolic activity of the liver and uses it to maintain energy balance. It also receives information from the emotion/reward system. Food is a rewarding object that induces pleasant emotions. Findings here The amygdala is largely responsible for this. Studies have demonstrated that when the reward value of food decreases, so too does eating motivation. Sadly, these studies often include the injection of lithium after eating, of which causes discomfort. But it does raise an interesting point in terms of the fussy eater in your life. We’ll revisit this later. Food reward is elicited by several events that occur before it even passes through the oesophagus, namingly the appearance and shape of the food, the taste and smell and then the pleasure of swallowing the food. We know this because in tube-feeding studies, reward sensations are reduced. In short, when subjects were no longer allowed to taste or chew it, they did not want to eat it. That said, in sham studies, when animals are denied nutrition because everything swallowed leaks out of a tube connected to the oesophagus, they eat and swallow more than usual, but they are still unsatiated. This tells us just how complex eating behaviour actually is. And provides food for thought for the gluttonous dog (on the other side of the scale). Hormones Hormones are probably the most talked about in terms of eating behaviour. You’ve all likely come across leptin and ghrelin. Leptin is produced in adipose cells, or fat cells. So, the more fat cells there are,the more leptin. In short, the more fat available in reserves, the less you need to eat. If you have no fat cells, you need to conserve your energy until you next find food. Leptin crosses the blood-brain barrier, and there are high numbers of leptin receptors found in the hypothalamus, brain stem and other regions of the brain. Rising leptin in a fed state inhibits food intake by suppressing a range of peptides involved in eating behaviour. Ghrelin is predominantly secreted in the stomach and it too modulates cells found in the hypothalamus by increasing excitatory inputs and decreasing inhibitory inputs. Here we are talking about neurotransmitters. These chemical messengers modulate much of our and our pet’s behaviour and they either make something do something or stop something from doing something. Whilst dopamine can be both inhibitory and excitatory, ghrelin is seen to have a large influence on the release of dopamine via increases in cell excitability. As dopamine is involved in reward and motivation, ghrelin is thought to target the motivational functions geared to gaining food and to select those which are more rewarding (high calorie). Findings here In eating disorders, dopamine is one of the neurotransmitters that gets a lot of attention. In times of reduced food intake (fussy eating), dopamine neurons are activated, in the short-term rewarding the lack of food. It is considered that it is a physiological response in an attempt to increase motivation to forage for food. Findings here However, there are also other mechanisms in which the dopaminergic system comes into play for the fussy eater. A central feature of the dopamine neuron response is that it is triggered by unexpectancy. After receiving an unexpected reward like food (or how many likes our recent post has got on social media) a dopamine surge is elicited. When this becomes a regular occurrence, the dopamine signal is triggered by the conditioned stimulus in predicting the reward. However, the dopamine system does not respond when the reward is received. If the reward is predicted, then not received, there is a dip in dopamine activity. What this means, is that your dog may do the song and dance ready for their bowl of food, but then walk a way as soon as it is placed in front of them. The reward they predicted (tasty food), isn’t what was received. The other neurotransmitter that gets a
If you’ve just rinsed your dog off after a meander through the woods, then their licking is likely grooming behaviour. But, here at My Pet Nutritionist, we often see dogs who excessively lick causing abrasions and hair loss. Whilst it’s often indicative of an irritation, there are in fact some other reasons why your dog may start licking in the absence of a jaunt through a muddy puddle. Let’s take a look at some of the more common causes. 1) Stress Yes – stress can take the blame for this one too! Stress is like the wonder woman of life – is there anything she can’t do? For anyone who has spent time investigating dog behaviour, you’ll know that lip licking in particular is a sign of stress. An interesting theory here suggests that because stress depletes essential nutrient resources, lip licking is in fact a sign of malnutrition. Deficiencies in a range of nutrients like vitamin B2, B3, B12, iron, and Vitamins A, C and K and Zinc have all been known to cause irritation and inflammation in and around the mouth and lips. The licking is thought to be an attempt to soothe it. Findings here However, other suggestions explore the idea that the lip licking mechanism is thought to soothe the stress response by activating the parasympathetic nervous system. Yet, this mechanism can apply to licking of all body parts, not just the lips. The stress response is dominated by the sympathetic nervous system; it increases heart rate, widens eyes in order to assess the threat better and redirects resources in order to deal with it. Once the threat has passed, the parasympathetic nervous system kicks in and re-balances. The chief of the parasympathetic nervous system is the vagus nerve, and chewing, along with licking is considered to activate it. Through the action, attention is redirected and focussed on that particular task, not what is making them stressed. Findings here Licking is also deemed a self-soothing behaviour through its association with oxytocin. Oxytocin is a hypothalamic nonapeptide linked to increased levels of social interaction, well-being and anti-stress effects. Oxytocin is released by sensory stimulation (touch) and promotes the release of dopamine whilst decreasing the cascade of stress response mechanisms throughout the brain and body. Oxytocin also modulates the activity of serotonin which as we know is a key hormone in mood stability, feelings of well-being and reward. An element of this could have also been learned behaviour from their mother. Licking and grooming behaviour is a key feature in determining neural changes and fear responses in offspring. Those from low licking mothers tend to show a greater stress-response and proceeded to be low-lickers themselves (if they were female and had their own litter). The same also occurred for high lickers. Findings here The bottom line? Excessive licking could be a response to stress faced by your dog. Watch out for other signs of stress like: Panting in the absence of exercise Salivating in the absence of food Pacing Inappropriate toiletting Unusual vocalising Out of character behaviour Wide eyes Flat ears Abnormal tail placement Work to remove the trigger and support them with other stress reduction strategies. Also, be mindful that chronic stress can deplete essential nutrient resources. our Calm Complex can help support the above signs of stress. 2) Pain Pain is an uncomfortable feeling that gives us and our dogs an indication that something isn’t as it should. Not only are many breeds incredible at hiding pain (it wouldn’t have helped them in evolutionary terms), but they also lack the ability to converse. Whilst we would all love to think we have this form of communication with our dogs, we can miss things, especially if they are pretty crafty at hiding them! The sensation of pain is a necessary function that warns the body of potential or actual injury. Whilst we may think that dull ache in our lower backs is merely an inconvenience, it’s a rather reliable indication that our office chair possibly doesn’t suit us. Pain occurs when a nociceptor fibre detects a painful stimulus on the skin or in an internal organ. This detection is picked up by other receptors in the spinal cord and brainstem and then transmitted to the various areas of the brain. This is done through the incredible work of neurotransmitters. There exists both inhibitory and excitatory neurotransmitters. Those that make things happen, and those that apply the brakes. Inhibitory neurotransmitters are involved in the modulation of pain; including enkephalins and endorphins, serotonin, noradrenalin, GABA, acetylcholine and oxytocin. Excitatory neurotransmitters acting without an inhibiting system results in pain. Which is why pain killers primarily prevent the release of some excitatory neurotransmitters (and can in fact make you or your dog drowsy). When we look at the neurotransmitters involved, it’s possible to see why our dogs may start licking an area that is painful to them. Through touch they can stimulate the release of oxytocin (a modulator of pain). Not only that but self-trauma (excessive licking) is thought to promote the release of endorphins, which are also pain modulators. Findings here This demonstrates how dogs can get into a vicious cycle, they want to lick to soothe, but the more they lick, the more trauma they cause, resulting in more licking. There is also the possibility, that what could have started as a pain response, could turn into irritation, or what started as irritation, could turn into pain and continue the cycle. 3) Itch Itch is a sensation felt on the skin, which causes the desire to scratch. Although initially it could be as simply as scratching something to remove it, itching can become stressful when excessive. When tissues are stimulated by allergens, histamine is released from mast cells. Histamine makes the blood vessels expand, driving blood to the area creating that common swelling among other responses. Specialised nerve fibres are stimulated; when these are processed, the scratching or rubbing reflex is stimulated. The main mediators for the itch
Help! My dog has a loose stool! Well, you wouldn’t be a true dog owner if you didn’t spend time assessing, talking or even sharing photos about your dog’s bowel movements. Here at My Pet Nutritionist, we’re not averse to a poop pic (we get quite a few in a day), but there are some common reasons why your dog may develop high scores on the Bristol Stool Chart. Technically that’s a chart for humans, but we can learn similar lessons. Here is our Ultimate Dog Stool Guide on colour and consistency. So, let us take a look at some of causes of runny poops in dogs. 1) Infection It goes without saying that a nasty gastro bug can result in runny stools. It can be all sorts of different colours, but more often that not it can be described as like turning a tap on! Infections can be a result of bacteria, parasites or virus and you may notice other symptoms like lethargy, vomiting or abdominal pain. In some cases, due to the irritation in the gastrointestinal tract, you may find specks of blood in the stool too. If nothing sinister, a fast followed by a bland diet will start to show improvements, but if there are other clinical signs or no improvements then its always best to get your dog checked out by your Vet. A vet call is always warranted for young puppies or elderly dogs. 2) Gut Dysbiosis Stool consistency strongly correlates with all known major microbiome markers. What this means is good poops are a sign of a healthy gut. But you knew that! Gut dysbiosis is when there is an imbalance between the good and bad bugs found in the gut. This can be for a number of reasons: Antibiotic use Steroid use Diet diversity Environment – exposure to toxins Birth method Use of flea and wormer treatments Vaccination When we are looking to heal the gut, we follow the 4 R’s. Remove (food antigens that could cause reactivity) Repair (the gut lining/endothelial, possibly known as leaky gut) Restore (the good bacteria in the gut) Replenish (with enzymes if necessary to reduce immediate inflammation) Signs of gut dysbiosis will usually manifest as regular sub-optimal bowel movements, if you think they may be an issue faced by your pet, we are more than happy to help! 3) Food Sensitivities/Allergies Allergies are in fact incredibly rare (at around 10%), but sensitivities are one of the most common issues discussed here at My Pet Nutritionist. An allergy is the result of an over-zealous immune system. It’s like going for the theory part of your driver’s test when you are told you are limited with how many clicks you can make on your hazard perception. Well, in cases of an allergy, the immune system didn’t get the limited clicks memo and gets a little trigger happy! The basic function of the immune system is to get rid of potential threats; it can do this by engulfing parasites, and you guessed it, causing a swift exit in the form of diarrhoea. But diarrhoea is also a sign of a food intolerance. Rather than an immune response per se, an intolerance involves the digestive system; in short, it struggles to process a particular food. This can be due to a lack of enzymes to digest a particular food, a sensitivity to chemicals found in certain foods or health issues like irritable bowel syndrome (which is often linked to bacterial overgrowth, stress, post-infection and genetics). In cases of food sensitivities, an elimination diet is the first port of call, to establish the key offender and we again follow the 4R’s in gut healing. 4) Stress Our pet’s stress response is much like ours as a human. Eustress or good stress can improve alertness and motivation and provide a helping hand in performance. But distress is the one we need to worry about, especially if it becomes chronic. Stress is generally known as the fight or flight response. The cascade of changes occurring in the body redistribute resources; blood is directed to the brain and limbs to figure out what to do, and whether to run away or stand and fight. Despite us making evolutionary progress, neither us or our dogs have yet evolved past this response and so even potentially minute stressors result in this redistribution of resources; taking ours and our dog’s ability to effectively digest food with it. Digestive function returns when the parasympathetic system kicks back in; once the stressor has passed (but incases of chronic stress, this doesn’t occur). In times of chronic stress, food is ingested, but not digested properly. This also explains why you may notice your dog has “adrenaline” poops on walks, or when they get particularly excited. As they are doing their zoomies, the body interprets it as stress and so directs resources where they are needed (not to the effective digestion of food). This is short lived and the dog’s next poop that evening has usually returned to its normal presentation but, under long term stress, this lack of digestion demonstrated by recurring loose stools, can result in a range of health issues thanks to the malabsorption of nutrients. If you consider your dog’s loose stools are generally associated with certain stressful events, the key is to remove the trigger where possible. Counter conditioning is often successful in supporting their future stress-responses. Stress does deplete essential nutrients, so opting for a fresh-food diet with excellent bioavailability is vital in supporting your dog during these times. 5) Underlying Malfunction Loose stools are the result of food being passed through the colon too quickly; with less fluid being absorbed by the body, the result being that puddle in your garden. As we mentioned earlier, a lack of digestive enzymes can be a reason for this. The digestive system comprises the GI tract, pancreas, liver, and gallbladder. If there is an underlying malfunction in any of these, you may find abnormal stools. The pancreas
You’re in the middle of your daily grooming session and you notice a thinning patch of hair on your canine companion. Without any obvious recent trauma to result in scar tissue and no replacement hair, your mind starts going to all the places it shouldn’t. A quick google search likely doesn’t help but well here at My Pet Nutritionist, we hope to give you possible solutions. There are in fact a number of reasons why your dog may start losing his hair, or having thinning areas, so let’s look at them in a little more detail. Hair growth occurs in stages: – Anagen – the growing phase – Catagen – the transition phase – Telogen – the resting phase – Exogen – the shedding phase An intact hair coat is maintained by the lifelong cycling of these phases. When a hair follicle has passed the telogen stage and shed it, if it remains empty for a period of time it is deemed kenogen. The anagen phase is restarted when epithelial stem cells are in good form. Stem cell activity is dependent on many complex interactions including: Immune cell function Nerve fibres Hormones Genetics Daylight Nutrition Circadian rhythm And stress 1. Hormones So much of a factor, there is a condition deemed hormonal alopecia in dogs. This can be linked to neutering with many owners reporting hair loss or thinning post neutering. But when we say hormones we are also considering thyroid hormones. The thyroid gland is in fact active in the initiation of hair growth and replacement. Located in the neck near the trachea or windpipe, this gland produces hormones which regulate metabolism. Both hyperthyroidism and hypothyroidism can result in hair loss in the dog although hypothyroidism is likely the more commonly occurring form of hormonal alopecia in dogs. Initially hair loss is patchy, the coat is dry, the hair is brittle and easily pulled out. Quite often hyper pigmentation occurs. In some cases, secondary pyoderma and seborrheic dermatitis may follow. The hair that remains is often stuck in the telogen or resting phase, hence it’s poor condition. Other signs of hypothyroidism includes: Weight gain Lethargy Increased susceptibility to infections Slow heart rate Abnormal nerve functioning which presents as non-painful lameness or lack of coordination Keratoconjunctivitis or dry eye Fat deposits in the corneas of the eyes Thyroid function is easily assessed through screening and if it isn’t running all on cylinders, then it can often be managed. 2. Nutrition It wouldn’t be a My Pet Nutritionist blog without mentioning nutrition now would it. Nutritional status affects hair growth and maintenance. Every cell in every body, including our dog’s, needs basic components to carry out their function. This includes immune cells, stem cells and hair follicles. The root of a hair is made up of protein cells and nourished by nearby blood vessels. As it grows, sebaceous glands near the hair follicles produce sebum which is made up of triglycerides, wax esters and cholesterol. Sebum lubricates the skin and hair to protect it from friction and therefore makes it impervious to moisture and/or pathogens. The hair moves through its phases, but new data is suggesting that even though telogen is defined as the resting phase, hair follicles aren’t doing that much resting. In fact, much cellular activity occurs during this phase so that tissues can regenerate and grow new hair. This means there is a demand for nutrients. Time and time again there has been a link made between nutritional status and hair health and growth. Low vitamin D status has been implicated in cases of alopecia Over-supplementation of Vitamin A is associated with alopecia In a Biotin deficiency signs include hair loss, Folate deficiency can result in hair, skin and nail changes Vitamin C is known to aid iron absorption, the latter being implicated in hair loss Hair loss is a common sign of zinc deficiency Hair loss can be seen in Iodine deficiency, also a mineral that aids thyroid function All things considered we would advocate afresh food diet which includes: Meat protein (haem iron is found in meat, chicken and fish and is more easily absorbed that non-haem iron found in plant foods). Oily fish (source of Vitamin D) Organ meats (good source of biotin) Leafy greens (folate came from the latin folium because it was first found in leaves!) Berries (source of Vitamin C) Meat and shellfish (source of zinc) Be mindful if you are tackling any other health concern which requires the elimination of any of these foods, we can always help you find alternative nutrient sources. 3. Stress Stress, we can confidently say is the bane of everyone’s life, including our pet’s. But what is particularly interesting is that in some cases, hair loss follows months after a traumatic event often making it difficult to connect the dots. As we have mentioned, hair cycles through different phases and all follicles can be at different stages at any onetime. Many will be in the growth phase or anagen phase before hitting telogen and ultimately shedding. But high levels of stress can cause a blanket shift in the phases and bump many of the follicles to telogen, all at the same time. The result? Bald patches or thinning. It makes sense evolutionarily. When facing a threat, what is more important? Brain and muscle function or hair growth? Stress triggers a sort of redistribution of resources, which in the short term is manageable. The issue is when faced with chronic stress. Hair loss as a result of trauma may not appear until the initial stressor has passed, the growth phase has been prematurely stopped, hitting telogen sooner, but then we still have to wait for the shedding to occur. We then need the growth phase to start again, which may or may not happen depending on the recovery from the stressor or in fact whether the host is still experiencing it. Stress also depletes nutritional resources along with impeding the digestion and absorption of them and as
Another one of the most common issues brought to us here at My Pet Nutritionist is Atopic Dermatitis. Most commonly seen in dogs, it can also occur in the cat. Atopic dermatitis is a multifactorial disease process, but it is defined as a genetically predisposed inflammatory and pruritic allergic skin disease often associated with IgE (immunoglobulin) against environmental allergies. The prevalence of AD is thought to be 10-15% of the canine population. Symptoms will include: Scratching Chewing Licking Recurrent skin, ear and anal gland inflammation and infections Hair loss Thickening of the skin It is thought that genetic abnormalities, along with an altered immune system and skin barrier defects all play a role. So, lets take a look at AD in a little more detail. Where it comes from and what, if anything, we can do about it. Genes Multiple gene expressions involved in skin barrier function and inflammation have been seen to go awry in canine atopic dermatitis. They have been both up and down regulated. Gene expression is like the instruction pamphlet that comes with your washing machine. Issues in gene expression is like you being sent an instruction manual in a different language and inadvertently using the 60-degree wash on your cold wash items! It’s not going to end well. Well, cheeky genes who aren’t doing what they’re supposed to, often doesn’t end well either. In dogs suffering with atopic dermatitis, data has shown: 361 genes that instruct inflammation, wound healing or immune response were up regulated. 226 genes that affect skin barrier function showed decreased mRNA. mRNA is a messenger; so low concentrations result in fewer messages. Findings here This is why certain breeds are known to suffer with AD, specifically, German Shepherds, Labradors, Boxers, West Highland White Terriers, French Bulldogs, Bull Terrier, Lhasa Apso, Springer Spaniel, Poodle, Dachshund, Miniature Schnauzer and Pugs. That said, these predispositions are also linked to geographical area, which also demonstrates how the environment can interact with genes. There is much attention being paid to the idea of epigenetics; how behaviour and the environment can affect how genes work. This is why, even if your dog is genetically predisposed, you shouldn’t throw in the towel, just yet. Skin Barrier Defects The skin is the first line of defence in our trusty immune system. This goes for our dogs too. If the skin isn’t as robust as it needs to be, then pesky allergens or irritants can get in and start to knock on doors of our second line of defence; inflammation. It is believed that part of the defects found in the skin barrier in AD cases is due to decreased concentrations of filaggrin. Not only can this be due to a genetic encoding error, but certain enzymes in the skin can breakdown filaggrin. The more enzymes, the more filaggrin gets broken down. Filaggrin is a protein found in the skin, and it binds to keratin filaments. This forms a structure within the skin cells. Filaggrin is essential to skill cell maturation, and in forming the outermost protective layer. It also forms part of the natural moisturising substance found in the skin; without it,cells dry out. This is why low levels of filaggrin result in dry, cracked skin. There is also evidence that filaggrin associated atopic eczema is more likely to lead to food sensitisation and inhalant allergens. Findings here Despite there being a genetic cause for filaggrin deficiency, the importance of maintaining a robust skin barrier is essential. Please take a look at our top tips for promoting skill health here. Altered Immune Response As we have mentioned, if pesky allergens or irritants get past the first line of defence, they soon feel the full wrath of the immune response. What starts with inflammation, will venture to a targeted attack in order to eradicate the invader. In the case of a defective skin barrier, the system will regularly be exposed to potential threats, of which the immune system must deal with. This constant state of firefighting ensures a steady level of inflammation throughout the body, which is why cases of dermatitis are often paired with food sensitivities. This is why tackling chronic inflammation is a key part of a dermatitis plan. As you have likely gathered, ensuring a robust skin barrier is essential in managing atopic dermatitis, but so is modulating the immune response and inflammation. Here are our top tips in tackling those three areas. Polyphenols Polyphenols are known to interfere with pro-inflammatory mechanisms. They have been seen to act upon keratinocytes which attenuate skin inflammation. Not only that but they have been seen to hamper toxicity of bacteria which regularly colonises the skin of atopic dermatitis affected patients. Polyphenols have been seen to inhibit the activation, proliferation, and function of Th2 cells which are key players in allergic reactions. Specifically, in the inflammatory response in allergic reactions. This has also been demonstrated during re-exposure to the allergen, suggesting that offending allergens may even be reintroduced at a later stage. Polyphenols are micronutrients found in certain plant foods; they are packed full of antioxidants. Their original role in the plant is to protect against UV radiation and of course aggression by pathogens. For that reason, they tend to contribute bitterness, astringency, colour, flavour, odour and oxidative stability. Under the umbrella of polyphenols, you will find phenolic acids, flavonoids, stilbenes and lignans (and a few more). Along with being anti-inflammatory and anti-microbial, the antioxidant capacity of phenolic compounds is also key to skin health. Oxidative stress is the imbalance between free radicals (the exhaust fumes of work) and antioxidants. Oxidative stress can damage the structure of the skin and negatively influence immune system function. Interesting, polyphenols have been seen to alter certain gene expression in the dog. Findings here So, all things considered, they are pretty nifty things to offer in your dog’s fresh food diet. Phenolic Compounds for The Dog Blackberries Raspberries Strawberries Blueberries Apple Pear Curly Kale Broccoli Green Tea (organic and decaffeinated) Parsley Chamomile Pomegranate Be mindful
Another particularly common issue we see here at My Pet Nutritionist is yeast! More technically known as candida, it is actually harmless when kept in check. The issue is when our dog’s system goes a little awry and can’t keep those little blighters from colonising. Whilst it sounds like a military operation, the dog’s system functions very much like that. Let’s take a look at yeast in a little more detail and how we can armour dog’s defences for a fighting chance! What is Yeast? Candida is an opportunistic fungal pathogen. It is a normal part of the gastrointestinal flora and genital tracts. Healthy systems are more than capable of keeping it in check with their beneficial bacteria. The issue arises when there aren’t enough good guys to keep the bad guys in check. The good bugs we find in our dog’s gastrointestinal tract will compete with the bad bugs for food sources and attachment sites. As we know there are a number of factors that can skew the microbial community found in our dog’s system. Antibiotics Broad spectrum antibiotics target all bugs,so whilst they get rid of the ones running amok, they also wipe out the beneficial ones too. Whilst the microbiome can recover to some extent, eventually; this takes time and there’s evidence which suggests key species are never fully repopulated. Findings here Stress There are clear links that stress, whether physical or emotional, affects the composition of the gut. On many occasions, stressor infliction significantly reduces the good guys. This has been associated with increased inflammation in the gut, which then continues the cycle. Findings here The Environment There is a huge amount of data which shows exposure to environmental pollutants significantly alters the gut microbiome. This includes bisphenols, phthalates, organic pollutants, heavy metals and pesticides. Bisphenol is an industrial chemical used to make hard, clear plastic. It is also found in epoxy resins which is often used as a protective later in some metal food and beverage cans/tins. Bisphenol has been linked to reduced microbiome diversity, and a significant decrease in protective bacteria. Phthalates are plasticisers and stabilisers found in vinyl flooring, clothing, detergents, personal care products, toys, medical equipment, and plastic packaging. Because they are non covalently bound to materials, they can leach into the environment. Phthalate exposure induces microbiota changes and has been known to inhibit the synthesis of certain short-chain-fatty acids. Heavy metals are associated with reduced microbiota diversity along with the altered metabolism of vitamin E and bile acid. Findings here Pesticides are renowned for altering the gut microbiome. This not only includes the pesticides administered to pets (flea and tick treatments), but also those found in the environment, particularly those sprayed on public footpaths. What is also worth considering is that antibiotic use has been seen to increase bioavailability of pesticides within the body. Findings here You are what eat! Of course, nutrition also plays a part in modulating the gut microbiome. But we always knew that. We are all pretty selfish in evolutionary terms, and this includes the bugs we find throughout our body. Our ultimate aim, and theirs, is to survive. So, we just need to modify how many of them actually do. This means keeping the colonies of good bacteria strong, so offering our dogs a diet full of pre and probiotic foods! Prebiotics are like the fertilisers in the garden, they help to feed and grow the beneficial bacteria in our garden. Probiotics however contain live organisms which can contribute to the population of the garden. Findings here There are a number of prebiotic foods suitable for dogs and they include mushrooms, chicory root, garlic and dandelion greens. Probiotics include fermented food, but supplements are available; soil-based are a good call for your canine friend (hold off on the fermented food until later, if your dog has already developed an overgrowth). Yeasts seem to like sugar as fuel, so diets high in grains, starches and other carbohydrates seem to contribute to an overgrowth. Generally, certain beneficial bacteria will metabolise these sugars, keeping candida in check by disrupting its food supply, but in the absence of good bacteria, candida is partying it down at the all-you-can-eat buffet! Immunity A weakened immune system is also a huge risk factor for developing a candida overgrowth. Whether this has been a natural progression over a period of time for a range of factors, or even due to medications like steroids. Immune function has natural peaks and troughs, young dogs and ageing dogs naturally have a lower function, but pre-existing conditions along with a range of medications can affect it too. The immune system is like a nosey neighbour. It keeps tabs on everything going on in the body and knows when something isn’t quite right. When it identifies something as non-self, it sends the army to fight the foreign invader and, all being well, wins, before sitting back down with its cup of tea. The issue arises when it can’t get up from its chair and so the foreign bodies are left to invade. There are a number of factors which can compromise immune function from sleep, to stress and nutritional status; there are several key nutrients essential to its performance. So, supporting this is essential in the prevention and treatment of any bacterial overgrowth. Top Tips: Adequate rest Reduced exposure to stress Nutrient dense diet withVitamins A, C, D and B’s, along with Zinc, Selenium, and Iron Address any pre-existing issues like inflammation in the digestive system or poor pancreas function which can contribute to poor nutritional status Findings here Careful use of medications like antibiotics, NSAIDs and steroids Findings here on Vitamin D Findings here on Zinc What if your dog has already got an overgrowth? If indeed your dog has developed a candida overgrowth, you will notice symptoms like: Ear infections Greasy coat Sores Odour (yes, that cheesy type of smell) Green/yellow discharge Crusty/flaky skin Hair loss Itching/scratching Incessant licking/grooming of an area due to irritation Rust
Halitosis, as it’s more technically known, in dogs, can be a symptom of a range of health concerns. Ranging from dental disease to some cheeky gut bugs overworking, bad breath is often the first sign things may not be as they should, so lets take a look at the more common reasons and what options are available to you. 1) Periodontal Disease Periodontal disease begins when bacteria in the dog’s mouth forms to create a substance called plaque. The plaque sits on the surface of the teeth and with the help of saliva, it hardens to form tartar. Not only does it sit on the teeth, plaque and tartar seeps into gum lines which causes inflammation. Over a period of time, this inflammation and presence of bacteria causes damage to the structures surrounding the teeth; causing receding gum lines and eventually tooth loss. Not only are the mouth and teeth a concern, but the bacteria found in the mouth of your dog can be released into the circulatory system, which then travels through the body. It has been found to damage cardiac tissue causing endocarditis (infection and inflammation in the heart). Studies have also shown that periodontal disease is linked to increased insulin resistance, kidney and liver issues. Findings here The mouth is full of bacteria, primarily to form a first line of defence to protect us and our pets from the bad bugs, but the bad bugs can use carbohydrates, known as starches, as fuel, and subsequently thrive. These bacteria destroy enamel which further develop into cavities, or holes. This is why, in most human literature we are told to avoid sugars for the benefit of our oral health. It stands to reason that we would want to avoid starchy food for our pets too. A fresh food diet is as standard, low in starch, but the inclusion of raw meaty bones, if appropriate, can also create friction when eaten and contribute to the prevention of build-up on the teeth. Please note common dry foods on the market, although not marketed contain between 18-60% carbohydrates. So, if your dog’s breath could keep a vampire away, you may want to check his oral hygiene. Look for build-up, grey/brown deposits, and any breakdown of teeth. 2) SIBO Whilst it sounds like a mission to outer space, SIBO is actually a little more common than that. Small intestine bacterial overgrowth is getting increasingly common in the pet world. Whilst we usually define the microbiome as the microbial community found in the whole of the digestive tract, abundance generally increases from the stomach to the colon So, we would generally find more microbes the further down we go. SIBO occurs when we get more than we bargained for in the small intestine. It is more commonly associated with surgery, or rather a complication of surgery, but it can also occur as a result of any disease which slows the passage of food and waste products down. This means they stay in the wrong place for too long, and we all know what happens when you’re in the wrong place at the wrong time. SIBO is often associated with cases of IBD or IBS, but there must also be consideration given in times of chronic stress as we know motility is affected here. Symptoms of SIBO include loss of appetite, abdominal pain, nausea, bloating, diarrhoea, and weight loss. Due to the overgrowth of bacteria, bad breath is often a symptom. Unfortunately, there are a number of complications associated with SIBO. It can result in poor digestion and absorption of fats, proteins and carbohydrates. Bile salts that are usually required to digest fats are often broken down by the bacteria, leaving few left to digest the fat in the diet. This then leads to reduced absorption, transport and utilisation of any of the fat-soluble vitamins, A, D, E and K. The overgrown bacteria also utilise the B12 marked for host use, subsequently leading to B12 deficiency. SIBO is also indicated in cases of immune deficiency, cirrhosis, and pancreatitis. Findings here Nutritional management plays a huge role in SIBO, so if you are concerned your dog may be showing symptoms, then please book a consultation here. Gut Guardian 3) Liver Disease When the liver isn’t performing to its fully capacity, it can result in potential toxins still circulating in the body. This includes the lungs. On exhale, this can present as a strong faecal smell (be mindful we are dealing with dogs, and some of them do perform coprophagy: eating poop). However, in cases of liver disease you would notice other symptoms such as loss of appetite, weight loss, increased thirst, increased urination, jaundice (yellowing of the gums and eyes), weakness and loss of stability and in some cases seizures. Liver disease can occur as part of ageing, or there are genetic predispositions. However, oxidative stress is a significant contributor to liver complications. Risk factors associated with oxidative stress include: Obesity Diets high in processed foods Exposure to radiation Pollution Exposure to pesticides Not only that, but the body’s natural immune system can also trigger oxidative stress. This is a normal process that is swiftly managed in a healthy system. The concern is when your dog’s immune system is regularly being called to duty, over not-so-threatening threats. This state of chronic inflammation can result in higher levels of oxidative stress, putting pressure on many body systems. A diet high in antioxidants can help modulate oxidative stress, but if you are concerned about your dog’s liver function, then it’s best to speak to a qualified practitioner. If you would like to read more about liver disease, then check out our blog here. Liver Guard 4) Kidney Disease Another part of the detoxification system, when the kidneys aren’t doing what they’re supposed to, excessive urea can end up in the bloodstream resulting in a halitosis. This odour is described as ammonia smelling and having a metallic taste – but as our dogs can’t talk, we’ll just have
We first started becoming interested in bugs when germ-free mice, those born and raised in sterile environments showed exaggerated responses to stress compared to normal controls. What is particularly interesting is that the use of pro and prebiotics were able to reverse the abnormal reactions found in germ-free mice. Not only that but the faeces of depressed mice could be transplanted to “happy” controls and subsequently make them depressed and vice versa. So, we started wondering, can bugs really affect our behaviour? The short answer is yes. The long answer needs a sit down with a coffee. The gut microbiome comprises of all microorganisms and their genomes inhabiting the intestinal tract. These microorganisms perform important functions in the immune system and basic metabolism by providing essential inflammatory mediators, nutrients, and vitamins. But, as we established, they also affect behaviour, and they do this through this thing called the gut-brain axis. This occurs through multiple pathways such as endocrine, immune, metabolic, and neural, specifically the vagus nerve. The vagus nerve is the longest nerve in the body and has countless branches from the brainstem all the way down to the lowest part of the intestines, touching most organs along the way. This is why it is also called the wandering nerve. The vagus nerve modulates the parasympathetic nervous system which counterbalances the sympathetic nervous system. In short, stress inhibits the vagus nerve. This effect is seen when gut motility is altered during stress. What surprised most was that brain-gut communication is bidirectional. This is why the jury is still out on whether cases of IBD or IBS are a cause or a consequence of abnormal gut-brain processing. The vagus nerve contains fibres. 80% of them carry information from the body to the brain and 20% from the brain to the body. These fibres are distributed in all the layers of the digestive wall and they sense the diffusion of bacterial compounds and metabolites. The bacterial sequences identified in the canine gastrointestinal tract fall into five phyla: Firmicutes Fusobacteria Bacteroidetes Proteobacteria Actinobacteria In an ideal world, we want balance, but there are several factors which can affect the composition of the intestinal microbiota which is subsequently known as gut dysbiosis. This composition, as we have established then influences behaviour, for better or worse. The Effect of Diet Several studies have demonstrated that diet composition, especially those with large differences in macronutrient composition (carbohydrate, protein, and fat) largely affects gut microbiome profiles. Dogs fed a raw diet have demonstrated a richer and more balanced microbiome when compared to kibble-fed controls. Raw fed dogs show an overall decrease in the abundance of firmicutes and Bacteroidetes. This isn’t surprising as these genera are associated with the digestion of dietary fibre, indicating a decrease in the fermentation of carbohydrate (raw diets are general lower in carbohydrate). Adding fresh meat to a bowl of kibble has also demonstrated a decrease in faecali bacterium and an increase in clostridiaceae. One of these clostridiaceae strains was later identified as being associated with normal bile acid metabolism which is an important pathway for lipid digestion and regulation of intestinal inflammation. Clostridiaceae is also associated with improved fecal health score (firmer). And yes, the bit you have been waiting for, clostridiaceae is associated with normal cognitive function. Findings here Biologically appropriate diets have also demonstrated increased levels of faecal GABA, which is an inhibitory neurotransmitter implicated in anxiety and mood disorders. Findings here In short, what is abundantly clear, the more diverse the diet, the more diverse the microbiome. This gives us a better shot at having beneficial bacteria to influence our health and behaviour. Birth Regardless of the species, GI colonisation starts before the new-born exits the birth canal. In humans the delivery method of the baby isa clear influence on microbiome development. But in the canine world, it is considered that the new-born puppy is exposed to vaginal and faecal microbiota through the dam’s tongue and therefore the delivery method, whilst still applicable, is likely less pronounced. It does however highlight that the Mother’s microbiota is a clear influence on the developing new-born, so her diversity will subsequently affect her offspring. Disease Dogs with gastro-intestinal disease regularly present with significantly decreased faecal bacterial diversity. The microbial communities differ massively between sick and healthy dogs. Findings here Manipulations of the microbiome are often included as part of the treatment of GI disease, most commonly antibiotics, probiotics, and faecal transplants. The aim of antibiotics is to remove pathogenic bacteria, however many antibiotics are broad spectrum, so they take the good guys with them too. They rapidly cause significant drops in taxonomic richness and diversity and there turn to the initial composition is rarely fully achieved. The link between bacteria and behaviour is again highlighted in human data reporting anxiety, panic attacks and in some cases depression as side effects to antibiotic use. Manic episodes have also correlated with antibiotic use. Findings here Turning this on its head, there is increasing attention being paid to using antibiotics as a possible treatment for psychiatric conditions like schizophrenia. Findings here Pathogenic bacteria have been seen to affect behaviour in other species than humans too. Rabies for example is largely associated with aggressive behaviour because biting is an effective form of transmission. Low serotonin levels are associated with aggressive behaviour, so it is considered that the rabies infection impairs serotonin neurotransmission. Findings here Not only that, but rat infection of toxoplasma gondii removes a rat’s natural aversion to cats and produces a pheromone to attract the rat to the cat. This gives the parasite a better chance at survival but is very unfortunate for the rat. Findings here Other mice studies have demonstrated that sub-clinical infection of campylobacter jejuni produced anxiety-like behaviour despite the fact there was no overt immune system activation. Findings here It would be easy here to say that the solution is to eradicate all bacteria, but the issue isn’t that the bacteria exist, the issue is the balance. For example,
Anxiety…the word that gets 337,000,000 hits on google. Many of us and our dogs would say, around that many things make us anxious in any one day, but anxiety for the dog can sadly be very life-limiting. Common signs include panting in the absence of exercise, pacing, salivating in the absence of food, inappropriate vocalisation, hyper-arousal, or lethargy and repetitive or compulsive behaviour. Not only that, but there are recognised cases of separation anxiety in the dog where they will dig at exit points, toilet inappropriately and the above behaviours become worse when separated from their guardian. Causes of anxiety are vast, what some dogs will find exciting, others will find stressful. This is where a better understanding of anxiety lies. In humans, anxiety is defined as a fear or worry, whereas stress is a response to a threat or situation. In the dog, if we consider separation anxiety, whilst dogs may respond to the trigger of you picking your keys up, or getting your coat, they exhibit a stress-response. Seeing as bonfire night is upon us, we thought we would talk about how to support and modulate this stress response. Stress is a response in the autonomic nervous system. The sympathetic nervous system primes for flight or flight. The parasympathetic nervous system then comes along to balance it all out, and primes to rest and digest. Whilst this is a very generic overview of the stress-response, there are many processes that are going on, on the inside. To this end, certain nutrients can support and modulate stress responses and help to maintain a balanced system. Magnesium Often noted as the ultimate chill pill, magnesium is an essential nutrient that many are deficient in. Its low levels are regularly established incases of depression in humans, so it is clear it plays a role in mood modulation and the stress response. Findings here Magnesium affects a number of neurotransmitter systems. Firstly, it inhibits excitatory neurotransmitters. Excessive excitation can lead to the death of brain cells, which affects the overall structure and functioning of the brain. Magnesium also acts as a cofactor in the serotoninergic system. As we know serotonin is the happy chemical, and low levels of magnesium are regularly linked to low serotonin levels. Not only that, but magnesium excretion is increased during times of stress. Catecholamines and corticosteroids enhance the shift of magnesium from inside the cell to outside of the cell leading to increased urinary excretion. In turn, low magnesium levels increase the release of stress-associated hormones. This unfortunately creates a cycle of a reduced resistance to stress. Magnesium is found in leafy greens, nuts and seeds. The ones packing the highest punch are spinach and pumpkin seeds. Magnesium is also necessary for calcium absorption, so balancing these levels is key. High levels of calcium increase the need for magnesium. High dosages of vitamin D can also induce magnesium depletion. As an aside, magnesium competes with fluoride in the body and will decrease absorption, minimising the impact of fluoride in the body. Knowing that magnesium is a key player in many of the systems necessary for balanced mood and can be depleted further in times of stress, it pays to add magnesium rich foods to your dog’s diet. L-Theanine An amino acid found in tea leaves; its relaxing effects have been noted in humans for a while now. This is appearing to be true for our canine companions too. In mammals, L-Theanine can cross the blood-brain barrier within an hour after administration. It appears to remain in the plasma and brain for several hours after. L-Theanine isseen to facilitate the generation of alpha waves which are indicative of a relaxed but awake and alert state. L-Theanine helps regulate the usual stress responses like increased blood pressure, heart rate and cortisol secretion. In dogs, L-Theanine treatment has been seen to reduce anxiety scores during storms in fear of humans. Findings here There is also evidence for L-Theanine improving cognitive function and performance in test situations. Findings here It is thought that because of its similarity to glutamate, it can interact with the same receptors, therefore playing a role in neuroprotection against glutamate toxicity. There are also reports of increased GABA activity in the brain following L-theanine administration and we know that GABA is the brakes of the brain. Findings here Green tea contains the highest L-theanine content, and in moderation is perfectly safe to offer to your dog. Alternatively, there are a number of L-theanine supplements available. Findings here Vitamin D Every tissue in the body has vitamin D receptors, but it is the ones in the brain we are most interested in. Vitamin D activates genes that regulate the immune system and release neurotransmitters. In humans, vitamin D receptors are found in the same brain regions that are linked with depression, so we know it has an impact on mood; seasonal affective disorder ties in with this. It is thought that vitamin D plays a role in calcium balance in neurons, which helps to balance excitatory and inhibitory pathways in the brain. Not only that but vitamin D is linked to the regulation of nerve growth factor which is essential in neuronal survival. Offspring of vitamin D deficient mothers often experience learning and memory problems with altered grooming behaviours, and we know that grooming in most mammals is calming and comforting. Findings here The long and the short of it, vitamin D deficiency is regularly noted in cases of anxiety. Findings here Dog’s don’t have the same ability to synthesis vitamin D from the sun as we do, so they rely solely on dietary sources. Sources of vitamin D include oily fish, red meat, liver, and eggs. There are several health issues that affect absorption of vitamin D, like IBD and exocrine pancreatic insufficiency along with having a low-fat diet. Supplementation is an option but being fat soluble be mindful of levels. Magnesium assists in the activation of Vitamin D, so ensure adequate levels of Mg before you
Whilst carbs are generally demonised in human and pet health, if you want to reap the rewards of fibre, you’ll have to play fair with carbohydrates. So, let’s look at carbs for what they really are. A carbohydrate is a molecule made up of carbon, hydrogen, and oxygen, which is why you may often see them noted CHO. Their primary function is to provide energy. Carbohydrates are made up of three components, fibre, starch, and sugar. Sugar is a simple carb. Having fewer molecules to digest and breakdown, it sends an immediate burst of glucose into the blood stream. This is the one that tends to cause a ruckus. Fibre and starch, however, are complex carbs, having longer chains of molecules. Starch takes longer to digest, having a more gradual effect on the body and fibre is a non-digestible complex carbohydrate. So, whilst fibre possibly doesn’t get the attention it deserves, and carbohydrates are routinely demonised, the heath benefits are often overlooked. Fibre, you may be surprised to learn, can be a key player in maintaining absolute gut health and supporting anxious behaviours. 1) Fibre to support your dog’s gut barrier If fibre and resistant starch can’t be digested, what happens to it? It gets fermented by the bacteria living in the gut. This produces short-chain-fatty acids, also known as SCFAs. The most common SCFAs produced are acetate, butyrate and propionate and they all have unique roles. They provide fuel for intestinal epithelial cells, which strengthen the gut barrier and butyrate is known for its role keeping the junctions of the barrier nice and tight. Not only that but SCFAs are able to stimulate mucus production, which is vital for creating a barrier between the external environment and the underlying gut epithelial layer. Mucin production plays an important role in protection from harmful pathogens and immunity. Findings here 2) Fibre to support your dog’s well-bein As you have seen, non-digestible fibre gets fermented into SCFAs in the gut. SCFAs also exert effects on the brain. Not only have all examples of SCFAs been found in the brain, suggesting they can cross the blood-brain-barrier, they appear to modulate neurotransmitters and neurotrophic factors. Neurotransmitters are chemical messengers used by the body’s nervous system. Acetate has been shown to affect levels of glutamate and GABA. Glutamate is an excitatory neurotransmitter and is involved in virtually every major excitatory brain function. GABA is the brakes; it is an inhibitory neurotransmitter. GABA facilitates sleep and reduces both mental and physical stress, creating a calm mood for your dog. In the same strand, it seems all SCFAs can affect levels of tryptophan which is the enzyme involved in the synthesis of serotonin and we all know that serotonin is the happy chemical! Generally, the inclusion of dietary fibre has been deemed a highly appealing approach, which is simple and relatively low risk if you are looking to help support your dog’s mental well-being. Findings here 3) Fibre as a prebiotic for your dog Here is another word you may have come across, but along with probiotics and synbiotics, not really understood which one is which, or whether either even does anything! Well, prebiotics were first defined as “non digestible food ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one or limited number of bacteria in the colon, thus improving host health.” So, possibly without even knowing, if you included non-digestible fibre in your dog’s diet, you were likely including prebiotics already. All prebiotics are fibre. But not all fibre is prebiotic. Prebiotic substances have demonstrated the ability to manipulate the gastrointestinal ecosystem of the dog, improving the composition of their microbiota and overall improving immune system function in dogs. Short-chain-fructooligosaccharides and oligofructose seem to modulate the intestinal microbiota and aid absorption of certain minerals, whereas mannooligosaccharide exhibits a positive effect on immune system function. Yet is it noted that supplement studies are carried out on healthy dogs; little evidence exists considering the role in canine disease. That said, there are a range of foods that contain naturally occurring prebiotics including dandelion greens, berries, bananas, flaxseed, apples, carrots, asparagus and of course mushrooms! 4) Fibre for your dog’s heart Cardiovascular disease is an inflammatory disease and diet is often considered the cornerstone for CVD treatment. Many studies have demonstrated that high amounts of dietary fibre can significantly reduce the risk of CVD. It is thought that fibre reduces cholesterol and fatty acid absorption and reduces glucose absorption along with decreasing insulin secretion. SCFAs, which are fermented from dietary fibre, also have anti-inflammatory properties and inflammation is central to complications associated with CVD. Findings here 5) Fibre for your dog’s overall health Dietary fibre adds bulk to the stool, which can alleviate cases of constipation. Not only that, but healthy bowel movements are essential to anal gland health in the dog. On its journey, dietary fibre attracts water and turns it to gel during digestion, this not only slows the absorption of glucose but can trap potentially harmful substances. In the same strand, it can speed the transit of food through the digestive system which facilitates regular bowel movements. Findings here Commonly Used Fibre Although fibre is generally an umbrella term, there are fibres within fibres. Cellulose consists of glucose units bound by linkages that can only be broken down by microbial enzymes, those found in the colon. Cellulose is an effective stool bulking agent. Pectins are found in the skins of fruits, being water soluble and rapidly fermentable. Gums are viscous and sticky polysaccharides found in the seeds of plants; they tend to have a variable fermentation rate. 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. Fructo-oligosaccharides are polymers than contain up to nine sugars. FOS enters the colon intact and then is fermented by bifidobacterial and lactobacillus. FOS is fermented into SCFAs. This fermentation also reduces intestinal pH which can inhibit the growth
Whilst dogs do demonstrate emotions, and you’ve probably seen images doing the rounds on the internet, dogs don’t cry. They have tear ducts like us humans, but when we are balling at the dog dying in, I am Legend, our dog is probably still dreaming of squirrels, KO’d in front of the fire. Not only do our tear ducts allow us to cry, but they form part of a larger system which has a nifty function. This function applies to our dogs too. The Tear System The tear system in the eye keeps it wet enough to be comfortable; you may have come across certain breeds of dog with a condition known as dry eye. This is exactly what it says on the tin, the eye is simply too dry. Tears contribute to eye defences as they contain antimicrobial factors and wash away foreign bodies and dirt. Not only that, but because the cornea has no blood vessels, tears also provide a way of brining nutrients to its cells. The tear system has glands that make the tear fluid, openings that let the tears out and ducts inside of the nose that lets the tears drain through. After washing over the corneal surface, tears flow into the nasolacrimal system, draining into the nasal or oral cavity. The nasolacrimal duct begins with two small openings in the eyelids near the nose, one on the upper eyelid and one on the lower eyelid. Tears are composed of water, electrolytes,proteins, lipids, and mucins; between 60 and 500 different proteins have been identified in tear film. They are seen to have three layers. The mucous layer contains mucins, immunoglobulins, salts, urea, enzymes, glucose, and leukocytes. Mucins form a barrier which protect against pathogens and debris. The gel-like barrier also facilitates the movement of particles, preventing shearing damage. The aqueous layer consists of water, electrolytes, proteins, anti-microbial agents, cytokines, vitamins, immunoglobins, peptide growth factors and hormones. It lubricates, washes away foreign bodies, and nourishes the cornea with oxygen and proteins. Growth factors, vitamins and electrolytes are key to epithelial (cells that line the surface) integrity. The lipid layer, the outermost layer, contains a range of lipids. It reduces evaporation from the underlying aqueous layer and limits contamination from dust and bacteria. Tears are crucial to eye health. Tear secretion is complex. It responds to the conditions faced by the eye, but also influenced by a range of hormones and cytokine balance. Cytokine is derived from two Greek words, cyto meaning cell and kinos meaning movement. Cytokines are cell signalling molecules that aid communication in immune responses. They stimulate the movement of cells towards sites of inflammation, infection, and trauma. Cytokines are agents that modulate or alter the immune system response. Cytokines are classified into: – Lymphokines which are cytokines secreted by T cells and regulate the immune response – Pro-inflammatory cytokines which amplify and perpetuate the inflammatory process – Growth factors which promote cell survival and result in structural changes – Chemokines which stimulate migration of cells – And anti-inflammatory cytokines which negatively modulate the inflammatory response It makes absolute sense that when faced with an ocular threat, cytokine levels increase, presenting as the usual immune response, water and itchiness which is common with seasonal allergies or intolerances. But what is also interesting is that that the rest of the body can also influence tear production. Inflammation is an immunological defence against injury, infection, and allergy. Acute inflammatory response is short lived, levels are altered, the body is primed, the body fights, wins and returns to homeostasis. When there is a prolonged persistence of an antigen, chronic inflammation occurs and can have body wide ramifications. The most considered is how chronic inflammatory diseases of the gut can cause various health issues; inflammatory bowel disease for example is caused by cytokine-driven inflammation of the gut. This leads us to why, no matter what you apply to your white dog’s face, you can’t get rid of those stains. Tear Staining Epiphora as it is technically known is a condition which causes the abnormal overflow of tears. It results in reddish staining around the eyes. The physical shape of your dog can contribute to the development of it; their head shape and where their eyes sit. Some breeds of dogs can over-produce tears due to a turning in of the eyelashes or eyelid. Turning out of the eyelid is also known in Great Danes, Bloodhounds and Spaniels. There may also be congenital abnormalities resulting in too large an opening of the eyelids, common in brachycephalic breeds. Blockage of the nasolacrimal system can also result in the overflow of tears. This can be hereditary but can also be caused by inflammation of infection and in some cases tumour. There is also the risk of a foreign body lodged within the duct. However, inflammation, resulting in the overflow of tears can be infectious or immune-mediated. Supporting your dog’s immune system could be the missing piece of the puzzle when tackling tear staining. Immune Response and Inflammation There are many things that can kick start an inflammatory response in your dog: Untreated acute inflammation such as infection or injury Long term exposure to irritants (chemicals, polluted air etc) Chronic stress Over-nutrition and obesity (increased metabolic processes) Malnutrition But there are changes that can be made. Nutrition and Inflammation Dietary patterns high in refined starches, sugar and saturated and trans fatty acids have been linked to the activation of the innate immune system, resulting in an excessive production of pro-inflammatory cytokines. The consensus is that a less processed diet is associated with reduced markers of inflammation. However, calcium, magnesium, Vitamin D and Omega-3 Fatty Acids are thought to protect against inflammation. Findings here Add foods like green leafy vegetables and fatty fish like salmon, sardines, and mackerel to your dog’s diet. Beef liver is a great source of Vitamin D too! Antioxidants too help counter oxidative stress which is a key player in inflammation. Astaxanthin is a powerful antioxidant found in microalgae. It
Trillions of bacteria, viruses and fungi live on or inside of us. Maintaining a balanced relationship with them is to ours, and our pet’s advantage. Together they form the gut microbiome; a rich ecosystem that performs a variety of functions in the body. These bacteria can digest food, produce important nutrients, regulate the immune system and protect against harmful pathogens. A range of bacterial species is necessary for a healthy microbiome, but there are many things that affect our microbiome, including the environment, medications like antibiotics, and even the method of delivery when our pets were born. Diet is emerging as one of the biggest influences on the health of our gut, and subsequently our overall health. Whilst we can’t control everything that influences the composition of our gut, we can pay attention to what we eat. And probiotics are one of those things. Probiotics are live microorganisms that provide health benefits to the host when ingested in adequate amounts. They are not to be confused with prebiotics which are selectively fermented ingredients that result in specific changes in the composition and/or activity of the gut microbiota. Synbiotics are products that contain both. The term probiotics was first introduced in 1965; in contrast to antibiotics, probiotics are deemed to stimulate growth of other organisms (antibiotics are used to kill). Probiotics are live microbes that can be formulated into many different types of products from food to supplements. The most common probiotics you’ve come across will likely be lactobacillus and bifidobacterium. Probiotics are reported to suppress diarrhoea, alleviate lactose intolerance (in humans), exhibit antimicrobial activities, reduce irritable bowel symptoms and prevent inflammatory bowel disease. With a rap sheet like that, we need to explore these functions in a little more detail. Probiotics in Gut Barrier Health The intestine possesses a barrier. It acts as a selectively permeable barrier permitting the absorption of nutrients, electrolytes and water but providing an effective defence against toxins and antigens. This barrier consists of a mucosal layer, antimicrobial peptides, and tight junctions. The mucosal layer has an important role in regulating the severity of infections. An altered mucosal integrity is generally associated with inflammatory bowel disease. There is evidence that certain strains of the commonly deemed bad, Escherichia coli can prevent the disruption of the mucosal layer and can in fact, restore it when damaged. Findings here Mucin glycoproteins are large components of epithelial mucus and several lactobacillus species have been seen to increase mucin production in humans. This mucin is key in preventing the adhesion of potential pathogens in the gut. Probiotic microorganisms expressing antimicrobial peptides could also be efficient in bacterial control. Findings here Tight junctions are key to barrier formation and certain strains of bacteria, lactobacilli for example, modulate the regulation of several genes encoding adherens junction proteins. The gut is maintained by the expression of both adherens junction and tight junction proteins. Findings here There are also links between inflammation and intestinal permeability. Certain probiotics have been seen to prevent cytokine-induced epithelial damage. Findings here Competitive Microorganisms A healthy gut is when the balance is tipped in favour of the good bugs. The issue is that every microorganism’s purpose in life is to survive. To survive in the intestinal tract, species must compete for receptor sites. To do this,they have a few tricks up their sleeve. Species will create a hostile environment for other species, they will eliminate receptor sites, produce, and secrete antimicrobial substances and deplete essential nutrients other species need to survive. Lactobacilli and bifidobacterial have been shown to inhibit a range of pathogens including E. coli, Salmonella, Helicobacter pylori and Listeria. Findings here Gastrointestinal Disorders where probiotics have shown benefit: Antibiotic associated diarrhoea– several randomised controlled trials have demonstrated AAD may be prevented by administration of probiotics. Colitis – Studies are somewhat inconclusive, but it is recommended to follow antibiotic treatment in these cases, with a course of probiotics. Infectious diarrhoea-significantly shortened using probiotics. IBS – Bifidobacterium demonstrates significant effect in reducing IBS symptoms. Findings here Probiotics and the Immune System Probiotics play a role in the delicate balance between necessary and excessive defence mechanisms in the innate and adaptive immune systems. One mechanism in which they do this is through gene expression. Certain strains of bacteria have been seen to regulate genes mediating immune responses. It was clear that the administration of certain strains modulated inflammation (L. acidophilus), wound healing,cellular growth, proliferation, and development (L. Rhamnosus). Other strains of bacteria have been seen to modulate Th1 and Th2 balance. These are cytokines which are hormonal messengers, responsible for most of the biological effects in the immune system. Th1 cytokines tend to produce inflammatory responses, responsible for killing intracellular parasites and for perpetuating autoimmune responses. However, excessive inflammatory responses can lead to tissue damage, so it needs to be balanced. This is where Th2 cytokines come in. Th2 include interleukins which have more anti-inflammatory responses. Th2responses help regulate Th1 responses. Findings here The importance of immune modulation at a gut level can be understood easily when you consider that approximately 70% of the entire immune system is found here and the thin layer of connective tissue known as the lamina propria contains around 80% of all plasma cells responsible for IgA antibody production (IgA is the first line of defence in the resistance against infection). Findings here Not only that but several bacterial strains are known to synthesise vitamins. Bacteroides, Bifidobacterium and Enterococcus are known to synthesise thiamine, folate, biotin, riboflavin, pantothenic acid and vitamin K. Not only that, but bacteria play a role in their absorption! Findings here Probiotics and Obesity Gut microbes play a major role in the energy extraction from food, through a variety of mechanisms. Many plant polysaccharides and complex carbohydrates cannot be digested by the host; however, the gut microbes can metabolise them to short chain fatty acids like acetate, butyrate and propionate. Butyrate provides an energy source for colonic epithelial cells and also plays an important role in modulating immune and inflammatory
