Graves Disease is an autoimmune disease involving the endocrine (hormone) system, specifically the thyroid, which we see from time to time here at My Pet Nutritionist. It can be a worrisome diagnosis for any pet owner, and it’s important that owners of pets with Graves Disease understand what it is, and how they can tailor their pet’s diet and lifestyle to keep on top of symptoms; which ultimately extends their pet’s comfort. That’s where we come in, to provide you our Ultimate Guide to Graves Disease in Pets. What is Graves Disease? Graves Disease is the non-clinical, or common, name for autoimmune Hyperthyroidism. You may have heard about Hypothyroidism quite regularly on social media and other platforms where pet owners connect, particularly on dog based platforms; but you may not have seen much discussion on Hyperthyroidism. Graves Disease is rare, but possible, in dogs but tends to be more of a frequent trouble for our feline companions. It can be found in us humans, too! So what exactly is Graves Disease? What happens when your pet has it? If you want the short answer, the thyroid gland in your pet is overactive – it’s working over time! We feel it’s important to understand more about it though, so read on! Graves Disease is an autoimmune condition. Autoimmunity tends to occur due to a damaged immune system, or in individuals with a genetically compromised immune system. The body essentially attacks itself, as it recognises various proteins and other substances in the body, as foreign. The thyroid is a gland which produces various hormones, essential for a healthy life. The hormones produced and secreted by the thyroid are called triiodothyronine (T3), and thyroxine (T4) – these help regulate the body’s metabolic rate. When there is a deficiency in these hormones, important bodily processes slow down, which causes a host of health issues. Now, when these hormones are too abundant, effects on the body can be equally as disruptive. We will discuss symptoms next. Symptoms of Graves Disease There are various symptoms of Graves Disease which you may notice in your cat or dog. Let’s take a look at some of the main symptoms: Weight loss, often rapid Diarrhoea Nausea/vomiting Swelling of the neck and face Increased urination Increased drinking Increased appetite Difficulty swallowing Shortness of breath and increases heart rate Change in pitch of bark Reduced eyesight capabilities Behavioural changes, including anxiety depression, and/or hyperactivity. Causes of Graves Disease The cause of Graves Disease is very much unknown. There is very little research into the causes of Graves Disease. It is often describes as ‘idiopathic’, meaning there’s no known cause. Some studies suggest that one known cause of Graves Disease in dogs (though rare) is as a result of a rapidly spreading cancer, called thyroid carcinoma. In cats, some cases of Graves Disease are secondary to a non-cancerous tumour forming on the thyroid gland called Adenomas. Like in dogs, in rare occasions, malignant tumours known as adenocarcinomas can cause the development of Graves Disease by causing the over production of hormones. It is possible that deficiencies in the diet may contribute to onset of Hyperthyroidism, as well as exposure to chemicals and toxins absorbed by the body, including flea and tick products which are toxins, and end up in the bloodstream, which disrupts the normal functioning of the thyroid. Diagnosing Graves Disease The first step in a diagnosis of Graves Disease, is a physical examination of the neck area of your pet. The purpose of this, is to feel for an enlarged thyroid gland. Secondly, the vet will take a blood sample to test for hormone levels in the blood. If the reading comes back with a value higher than the ideal’ threshold for each hormone, it’s very likely your pet has Graves Disease. If the T3 readings are high, but the T4 readings are ideal, more tests may be required, which would be discussed with the vet. These tests may include further bloodwork, and a urinalysis, which will show potential secondary defects to the heart and kidneys. As the thyroid is involved hormonally with the vast majority of the body’s organs, imperfect bloodwork in relation to other organs, could help show a problem with the thyroid. Conventional Treatments As always, here at My Pet Nutritionist, we like owners to be able to make an informed choice with their dog’s health, and encourage the use of conventional treatments where necessary in life potentially endangering situations, and situations where quality of life becomes the biggest importance. This is of course, alongside as much natural support as possible, and feeding a fresh, therapeutic diet. More on this later – let’s take a look at the conventional treatments your veterinarian may offer. There are various approaches which may be taken. As carcinomas are one of the most common, treatable reasons a dog or cat may have Hyperthyroidism, most are based around treating the cancer. Radioactive Iodine Therapy Radioactive Iodine Therapy is fairly common in practices which offer it as a treatment. The radioactive iodine is injected into the bloodstream, which makes its way to the thyroid gland. The thyroid gland takes the iodine up, causing radiation to be emitted. The emitted radiation then destroys any cancerous tissues around the thyroid, but does not cause any damage further afield. This treatment often results in normal levels of hormone production within mere weeks of the injection, making it extremely effective in curing hyperthyroidism. This treatment option has to be undertaken in a specialist veterinary hospital with licencing to carry and use radioactive substances. The pet must also be kept in the surgery until their levels of radiation are safe for handling. Findings Here Findings Here Medication Some drugs may be offered, to inhibit the production and release of hormones from the thyroid. As the thyroid is overactive, slowing it down is imperative to managing Graves Disease. This method will not cure, but can support the pet in reducing flare ups and secondary health implications. Being the
Here at My Pet Nutritionist, we deal with a lot of cases involving thyroid health and disease. These problems can be supported through nutrition; and there are some important vitamins and minerals that contribute to thyroid health. Read on to learn about the importance of vitamins and minerals for thyroid health! What is the Role of the Thyroid? The thyroid is one of the major glands in the body, which can be located in the neck, close to the trachea. It is controlled by another important gland, the Pituitary Gland, which is found at the base of the brain. The thyroid gland released various hormones, which are important for regulation of metabolic rate, heart rate and function, proper muscle function, cognitive development, growth and bone maintenance, and health digestion. Findings Here To find out more about hormones and their role in the body, read our blog: Hormones and Their Role in the Body Thyroid Diseases There are a number of thyroid diseases. Let’s look at a few. Hyperthyroidism When a dog has hyperthyroidism, the thyroid is over-active, meaning it produces too much of the associated hormones. Symptoms of Hyperthyroidism include: Behavioural changes, such as anxiety Restlessness Fatigue Overheating Diarrhoea Increased thirst Muscular weakness Itching Hyperthyroidism can be a dietary illness. Some years ago, thyroid glands were often recommended as part of the offal in a dog’s raw diet, however this was knocked on the head when studies began to show hyperthyroidism was a risk due to the consumption of excess hormones in the thyroid gland being consumed. Findings Here Read more about Hyperthyroidism in dogs here: Ultimate Guide to Hyperthyroidism And in cats here: Hyperthyroidism in Cats Hypothyroidism Hypothyroidism is the opposite of Hyperthyroidism, whereby the thyroid gland is under active. When the thyroid is underactive, it doesn’t produce enough of the thyroid hormones required for so many bodily functions. Hypothyroidism is much more common than hyperthyroidism. Symptoms of Hypothyroidism include: Weight gain Lethargy Low tolerance for cold temperatures Excessive shedding and baldness Dark skin pigmentation Dull coat and dry skin Reduced heart rate Dry eye Read more about hypothyroidism here: Ultimate Guide: Hypothyroidism Goiter These are caused by the lack of signals from the pituitary gland to the thyroid gland, which causes the thyroid gland to function improperly. Clinical presentation of a goiter, is swelling in the neck area, due to the thyroid gland being enlarged. While the goiter itself is not necessarily life threatening, it does signify an underlying condition which needs to be investigated by your veterinarian. Symptoms of goiter include: Swelling of the neck area Rapid weight loss Wheezing and shortness of breath, both at rest and during activity Difficulty swallowing Reduced appetite Goiters are often caused as a result of congenital (from birth) hypothyroidism. Findings Here Cancer The final major potential thyroid related health problem is Thyroid Carcinoma – a malignant tumour of the thyroid. The cause of this condition could be one of may things, and would be difficult to pinpoint unless on a case by case basis. It is, however, suggested that Thyroid Stimulating Hormone (TSH) may play a role in the formation of this cancerous tumour. Read more about the role of thyroid hormones here: Hormones, and Their Role in the Body Some cases are able to be helped through surgery, which is a procedure called thyroidectomy. Dogs undergoing this surgery will require daily medications for life. Some thyroid carcinoma patients undergo therapy with radioactive iodine. The path of treatment very much depends on the condition and placement of the carcinoma. Prognosis of those with thyroid carcinomas is generally good, to excellent. Symptoms of thyroid carcinoma include: Swollen mass in the neck area Difficulty swallowing Noisy/difficult breathing Change in bark Increased thirst and urination Rapid weight loss Findings Here Findings Here Important Vitamins Vitamin D Vitamin D is an essential, fat soluble vitamin, used for metabolic purposes, as well as digestion, heart rate regulation, muscle health, and many other bodily functions. One of the uses of vitamin D, is to reduce the risk of hypothyroidism. There are many links between vitamin D deficiency and hypothyroidism, as proven through various studies, which show a low content of vitamin D in serum samples from patients suffering with hypothyroidism. Sources of Vitamin D include: Egg yolk Salmon Red meats liver Findings Here Findings Here Vitamin A Vitamin A deficiency has been linked to thyroid issues, particularly hypothyroidism. Vitamin A deficiency is often associated with iodine deficiency; iodine is incredibly important to consume in the correct amounts to avoid hyper- and hypothyroidism. Iodine deficiency contributes largely to hypothyroidism. Sources of Vitamin A include: carrot sweet potato liver spinach kale broccoli oily fish eggs Read more about Iodine here: The Importance of Iodine in Dogs Findings Here Vitamin B6 Vitamin B6 is absolutely essential for healthy thyroid function. It is responsible for utilising iodine in the thyroid to produce thyroid hormones. If the body is lacking in Vitamin B6, the thyroid is unable to produce thyroid hormones, which has a major knock on effect on other bodily functions. Sources of Vitamin B6 include: banana avocado (flesh only) egg spinach liver red meat oily fish Findings Here Findings Here Vitamin B12 Another deficiency common in those diagnosed with hypothyroidism is Vitamin B12. Vitamin B12 is essential for red blood cell metabolism, which is massively linked to the thyroid gland. When the body lacks Vitamin B12, it is at a higher risk of pernicious anaemia. This is found most commonly in patients who have been diagnosed with an autoimmune thyroid disease. Sources of Vitamin B12 include: beef chicken oysters lamb egg turkey pork oily fish Read more about Vitamin B12 here: Why Your Dog Needs Vitamin B12 Findings Here Findings Here Findings Here Important Minerals Iodine As previously mentioned, Iodine is essential for thyroid function as it is the mineral that is used to produce thyroid hormones. Too little iodine can cause hypothyroidism, too much iodine can cause hyperthyroidism. Iodine consumption also highlights the importance of a meat
In Part 1, we discussed what Leaky Gut is, what autoimmunity is, and possible causes and symptoms of both. Read on to find out how they are linked, and more about the autoimmune diseases most commonly affected by Leaky Gut, as well as how we can support the body through diet, and supplements. How are Leaky Gut and Autoimmunity linked? A healthy gut microbiome is incredibly important as around 90% of the immune system is located in the gut! That’s quite a staggering figure, but it shows the importance of keeping the gut healthy and the microbiome strong. Let’s take a deeper look at some of the most common autoimmune diseases, and their link with Leaky Gut. Thyroid Issues One of the main issues with Leaky Gut and Autoimmunity, involves the thyroid. The body attacks the thyroid tissue as it recognises it as a foreign body. The reason the body sees thyroid tissue as a threat, is down to molecular mimicry. When the immune system releases antibodies to get rid of a threat, they bind at what is known as the ‘active site’, or ‘antigen binding site’. Antibodies are Y shaped proteins, and on the tips of the Y, the binding sites are found. These are a specific shape, to match the proteins on the antigens (the threatening particles). Take a look at the diagram at the top of this blog! Despite food particles clearly being very different to thyroid tissue cells, some of the attached proteins are the same shape on both the food particle and on the thyroid tissue cells. Gluten and Casein (dairy) are particularly alike to thyroid tissue cells, so when an antibody detects the protein it fits with, and binds to it, there’s a high chance it may be thyroid tissue instead of its real target; the food particle. Findings Here Findings Here Inflammatory Bowel Disease (IBD) A condition we hear a lot about, particularly on a professional basis as well as on social media posts when people ask advice on their poorly pets, is Inflammatory Bowel Disease. As per it’s name, this involves inflammation in the bowel, which can be as a result of Leaky Gut. When looking at IBD, diet is so important – many processed foods contain emulsifiers, which can include Cellulose Gum, and Polysorbate-80 (though this one is most inhuman foods, not pet foods). These have been found to interrupt interactions between the bacteria in the intestine, and the gut wall; resulting in the gut wall being less protected than it would be without the presence of these substances. This lack of positive interaction, teamed with the already permeable gut wall (due to Leaky Gut) can cause the onset of IBD. Findings Here Small Intestine Bacterial Overgrowth (SIBO), Yeast, and Candida can also contribute to IBD (and are all symptoms of Leaky Gut), which causes inflammation of the bowel, which further increases the risk of IBD onset. Studies show a huge affect on gut permeability when up-regulation of the protein called Zonulin is present. Zonulin helps regulate the permeability of the small intestine, but is detrimental in high numbers as it causes the gut to become more permeable. It is secreted by numerous organs within the body, and can be linked to Leaky Gut and the onset of IBD. Findings Here Findings Here Findings Here Immune-Mediated Haemolytic Anaemia (IMHA) IMHA is one of the more worrying autoimmune diseases, with a mortality rate close to 70%. There are many reasons a dog may be diagnosed with IMHA, including Vaccine Induced IMHA. When a dog has IMHA, the body is attacking it’s own red blood cells, which are important for transportation of oxygen from the lungs to all parts of the body for healthy muscle usage. IMHA can be caused in some rare cases, by a deficiency in Vitamin B12, which can be linked back to Leaky Gut. IMHA is also often as a knock on effect of other autoimmune diseases like Systemic Lupus Erythematosus. Findings Here Findings Here Diabetes Largely linked to Leaky Gut, Diabetes mellitus often requires lifelong medication. Similarly to the mimicry of thyroid tissues by antigens like Gluten and Casein, the onset of diabetes can be facilitated through normal cells being attacked incorrectly by the antibodies circulating the bloodstream. With diabetes cases, the immune reactions affect, and damage pancreatic beta cells (responsible for producing and secreting insulin), which then causes the over-production of cytokines, which in turn causes insulin resistance within the body. Healing the gut, and decreasing gut permeability may help relieve sufferers of diabetes symptoms. Studies show Type 1 Diabetes can be caused as a result of gut damage, but can also cause gut damage. Findings Here Findings Here Findings Here Findings Here Immune-Mediated Trombocytopenia (ITP) ITP is a platelet disorder, in which sufferers are unable to properly clot blood due to low platelet counts. Pathogenesis of ITP as a result of leaky gut has been proven to be due to imbalances in the gut microbiota, and the presence of cytokines which interfere with metabolism of fats. Patients with Leaky Gut, as we know, have a very imbalanced microbiome as bacteria leaks out through the channels in the gut wall. Certain strains of bacteria play an essential role at keeping ITP at bay, but are found to be of low levels in those diagnosed with ITP. When these helpful bacteria are leaked from the gut, cytokine production is increased, which then affects the metabolism of fats, which in turn causes pathogenesis of ITP because the lack of fat metabolism causes a lack of available fatty acids to enable the blood to clot. Findings Here Findings Here Findings Here Rheumatoid Arthritis The previously mentioned protein called Zonulin plays a part in Rheumatoid Arthritis (RA); a joint related autoimmune condition. Just like in IBD, when Zonulin is over-represented, the gut permeability cannot be controlled, and allows useful and harmful substances to enter the blood stream, which are then detected as threats by the immune system. The upregulation of
Iodine is an extremely important mineral to include in your dog’s diet. It has many uses in the body and is the backbone of many bodily functions. At My Pet Nutritionist, we understand the importance of micronutrients, and strive to educate pet owners in how to feed their pets with maximum health benefits. Let’s look at what roles iodine plays in the body, and where it can be found. The Role of Iodine in the Body Iodine is a trace mineral which cannot be made by the body. As it is so important, and cannot be produced by the body, it must be consumed in the diet of all mammals. Iodine is essential for healthy functioning of the thyroid. The hormones used by the thyroid, thyroxine and triiodothyronine, cannot be made without iodine. These hormones support a healthy metabolism, as well as protein creation and keeping enzymatic functions under control in the body. Linked to the support of enzymes, an iodine rich diet enables the body to use calorific intake as energy instead of being stored as fat. While doing this, iodine also helps rid the body of harmful heavy metals like Mercury. Iodine can also aid cancer prevention by causing a process called ‘Apoptosis’ to occur. Apoptosis is the self-destruction of cancerous cells. Acting as an antioxidant stimulator is another of iodine’s roles in the body, and in turn helps keep the immune system strong. If we compare canines to humans with regards to iodine turnover in the thyroid, the turnover of iodine in the canine is far more rapid than that in the human. Dogs are not as good at conserving iodine stores as humans are, and also deposit more in faecal waste, making iodine consumption extremely important. Findings Here Findings Here Sources of Iodine Iodine is found in the highest amounts in sea dwelling vegetation, and animal based proteins. The amount of iodine in different sea vegetable based supplements varies, so it’s important to choose one with a good amount of iodine, but not too high an amount. Findings Here Kelp Seaweed – dried – 6635mcg per 5g Wakame Seaweed – dried – 210mcg per 5g Nori Seaweed – dried – 116mcg per 5g Cod – cooked – 186mcg per 100g Oysters – cooked – 109mcg per 100g Eggs – cooked – 26mcg per egg Beef Liver – cooked – 16mcg per 100g Prawns – cooked – 15mcg per 100g Leafy greens – steamed – 8.8mcg per 100g Low Fat Fish Iodine Deficiencies There are numerous health issues caused by a lack of sufficient amounts of iodine in the diet. Let’s explore those. Hypothyroidism Hypothyroidism is caused by a deficiency of the thyroid hormones, which is caused by a deficiency of iodine in the diet. Iodine is a huge part of the synthesis of thyroxine and triiodothyronine, so with a lack of it, these hormones cannot be produced in the amounts required by the thyroid to avoid hypothyroidism. Symptoms of hypothyroidism include weight gain due to decreased metabolic rate, difficulty regulating body temperature/warming up, baldness/excess shedding, lethargy, and other skin related issues. One study also suggests a link between hypothyroidism and behavioural changes, but this is an avenue not fully explored yet. Some commercially prepared diets have been shown to lack the correct amount of iodine a dog needs, vs home cooked with and without suitable iodine supplements added, so no matter what you feed, if any of the symptoms above are present in your dog, you may wish to book a consultation with one of our team. Read more about Hypothyroidism here. Findings Here Findings Here Cancer Iodine deficiency seems to stimulate follicular cell-derived thyroid cancer. It may not be the base cause of the cancer itself (known as the ‘initiator’) but certainly stimulates carcinogenesis. Thyroxine therapy is often used in thyroid cancer cases, to suppress the cancer. Studies show carefully supplemented diets with sufficient iodine content result in less serious cases of thyroid cancers. Findings Here Findings Here Studies also show links between cancers of the breast and iodine deficiency. Treating canine mammary cancer with iodine alongside antineoplastic drugs is proven to be very effective. Findings Here Goiters Goiters are swellings of the thyroid gland, which present clinically as a lump in the throat. Often a direct result of an iodine deficiency, goiters can be rectified by increasing the amount of iodine in the diet. Goiters can also be caused by hypothyroidism, hyperthyroidism, or even thyroid disease, so its important to seek veterinary attention. Findings Here Can You Give Too Much Iodine? The short answer is … yes! There are numerous studies on dogs given too much iodine, and iodine toxicity is a condition to be mindful of. At My Pet Nutritionist, of course we recommend a well balanced fresh diet, whether that is raw or cooked, as per our recipes, however if you are feeding a commercially prepared dry food, be mindful that the food may either lack, have the correct amount of, or even exceed the required amount of iodine for your dog; we just don’t know! Hyperthyroidism is a risk when the dog has too much iodine in the diet. Symptoms of hyperthyroidism include weight loss due to a vast increase in metabolic rate, swelling of the neck/thyroid gland, excessive urination, excessive thirst, excessive defecation, and choking/vomiting. Read more about Hyperthyroidism here. Findings Here If you have any worries about your pet’s diet, or want to improve their diet, please don’t hesitate to book a consultation with one of our team! Team MPN x
If you have followed us here at My Pet Nutritionist for any length of time, you’ll know that we’re great advocates for the inclusion of veggies for their prebiotic and fibrous benefits. But there are also times where we would avoid certain veggies. Keen to learn more? Read on. Nightshade Vegetables and Arthritis Some believe that the solanine contained in nightshade vegetables like bell peppers, tomatoes and potatoes may increase levels of inflammation in the body. Whilst there is disagreement over the mechanism, humans suffering with arthritis often report a worsening of symptoms after eating nightshade vegetables. There is one school of thought that it could be more to do with a sensitivity to the food, which results in an inflammatory response, contributing body wide circulating cytokines. Whilst nightshade veggies are a great source of certain nutrients, there are other foods which can provide these and so if you notice a worsening of arthritic symptoms, it’s an easy change to make. Natural Arthritis Guide Lectins and Should My Dog Eat Them? Goitrogenic/Cruciferous Veggies in Thyroid Issues The thyroid gland produces three important metabolic hormones, thyroxine, triiodothyronine, and calcitonin. Thyroid stimulating hormone (TSH) produced by the anterior pituitary gland controls the production of these hormones. Iodine, derived mainly from sea-foods or consumed in the form of iodised salt, is utilised for producing T3 and T4 hormones. T3 and T4 hormones affect every cell and organ in the body. They regulate the rate at which the body uses energy, which subsequently affects weight loss or gain. They raise or lower body temperature. These hormones influence the speed at which food moves through the digestive system. They affect brain development and also control the way muscles contract. Common thyroid disorders in our pets include hypothyroidism and hyperthyroidism, meaning the thyroid is either under-active or overactive. Ultimate Guide: Hyperthyroidism Ultimate Guide: Hypothyroidism Goitrogens are plant chemicals that can decrease the production or activation of thyroid hormone, meaning they slow thyroid function. These foods are commonly known as goitrogenic, which means they contain substances which slow the thyroid’s ability to uptake iodine. If eaten in excess, these foods interfere with the efficient function of the thyroid gland. The strongest goitrogens are soy products, but moderate inhibitors include: Broccoli Cabbage Kale Cauliflower Brussels sprouts All/Starchy Veggies in Yeast Issues Around 150 strains of yeast are thought to utilise starch as a sole carbon source for aerobic growth. In short what this means is starch is food for yeast! Starch, or amylum, is a complex carbohydrate that exists in many foods, including grains, vegetables, and fruits. Sources of starch are primarily: Maize Tapioca Wheat Potatoes The extraction of pure starch from food produces a white, tasteless, and odourless powder that doesn’t dissolve in cold water or alcohol. Starch is a natural polymer, or polysaccharide, meaning that it is a long chain comprising one type of molecule. Starch consists of glucose molecules. It can occur in two forms: amylose and amylopectin. You may be familiar with this wording as amylase is a digestive enzyme which helps break down starch. Yeast or candida is an opportunistic fungal pathogen but a normal part of the gastrointestinal flora and genital tracts. The issue is when there’s an overgrowth. If we are tackling an overgrowth, the last thing we want to do it continue feeding it and as you’ve now realised, starch is a great food source for yeast! Is Your Dog A Yeasty Beasty? All Veggies in the Case of An Elimination Diet When we are supporting a dog with digestive issues, we need to know exactly what is contributing to their symptoms. For this reason, we would avoid feeding all vegetables when running an elimination diet. Just like a dog can have a sensitivity to a certain meat type like chicken or beef, they can also have a sensitivity to fruits and vegetables. It’s important to remember that an elimination diet is a diagnostic tool – not a long-term lifestyle and in some cases, a means to give the immune system a welcomed break. In running an elimination diet, we follow the 4 R’s. – Remove – remove offending foods, one at a time and note changes in symptoms. Quite often, even offending foods can be reintroduced at a later stage. – Repair – support immunity and gut healing with ingredients like slippery elm, de-glycerised liquorice, glutamine, and N-acetyl-glucosamine. It is also important to consider how existing medications are affecting gut healing for example, steroid use impairs intestinal absorption which is linked to several gastrointestinal dysfunctions. – Restore – as the microbiome is key in the development of the immune system, supporting this is essential, however, the introduction of specific pre and probiotic foods is often best left whilst we get to the root cause. – Replenish – indigestibility of food proteins can also contribute to their antigenic nature, so consider any long-term medication use including proton pump inhibitors which affect gastric acid secretion. Ensuring HCL, pepsin and digestive enzymes are in good supply will help get the digestive system back to doing what it does best! Elimination Diets For Dogs We can’t deny the fibrous benefits of many vegetables along with their nutrient content, but when we are tackling a specific health issue in a pet, we must prioritise. We can often get those benefits in other ways if we think outside of the box. If you would like any support with your pet’s health and some outside of the box thinking, then please check our services to see how we can help. Thanks for reading, MPN Team
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
Hyperthyroidism is commonly accepted as the most common feline endocrine disorder. These are the words found in a Journal of Feline Medicine and Surgery. Here at My Pet Nutritionist, this worries us for two reasons. 1) That hyperthyroidism is such a common disorder 2) That it is accepted Being noted as an epidemic, we think it deserves a little attention. So, let’s explore hyperthyroidism in a little more detail, and what, if anything we can do about it. Until the late 1970’s, there appear few references to hyperthyroidism in the cat. Were there sudden developments in veterinary science, or was something else afoot? What is the thyroid? The thyroid gland is part of the endocrine system. It is a small butterfly shaped gland in the neck. One of the main functions is to produce hormones to regulate the body’s metabolism (the process that turns food into energy). These are more commonly referenced as T3 and T4. Hyperthyroidism is when the thyroid is hyperactive – there is an increased production of thyroid hormones. Symptoms of Hyperthyroidism: Weight loss Increased appetite Increased thirst Increased activity Increased heart rate Poor coat condition Mild/moderate diarrhoea (yet some cats can demonstrate generalised weakness lethargy and loss of appetite) Many cases of hyperthyroidism can be medicated, and so complications are rare, but they can include: Cardiovascular changes High blood pressure Kidney damage (more commonly asa result of treating hyperthyroidism) Diagnosis is usually based on enlargement of the thyroid glands, but this is not always visible. A blood test will confirm levels of thyroid hormones. Treatment is generally with thioamides, which in short act as anti-thyroid medication. They do not cure, simply control, but they must be administered daily. Side effects of this medication can include poor appetite, vomiting and lethargy. Although in some cases, the thyroid gland has been removed. So, what causes hyperthyroidism? So far, there are two main categories of risk factors for hyperthyroidism in the cat. – Nutritional deficiencies – Exposure to thyroid-disrupting compounds There are too genetic risk factors associated with hyperthyroidism, for example Siamese or Persian cats are less likely to suffer with the condition where as domestic shorthaired are the more commonly affected. Findings here Nutritional Deficiencies As claimed in the Journal of Feline Medicine and Surgery, “the feeding of commercially prepared cat food is one leading candidate as a major risk factor for the development of thyroid pathology and hyperthyroidism in cats.” It claims that all epidemiological studies to date have identified feeding an increased proportion of commercially prepared cat food is a risk factor. There are arguments that in the last few decades, the cat food industry has been on a bit of a rollercoaster with iodine. First, they considered high iodine was implicated in hyperthyroidism, so they significantly dropped levels, and since, iodine content has ranged from non-detectable to extremely high, depending on the manufacturer. Iodine is a key element in the synthesis of thyroid hormones. Low iodine results in low thyroid hormone,which spurs the pituitary gland to increase its secretion of thyroid stimulating hormone (we all want to survive after all). Persisting high TSH leads to enlarged thyroid glands. Interestingly, when studied, cats fed a commercially prepared diet who were relatively deficient in iodine, were four times more likely to develop hyperthyroidism than cats supplemented with iodine. Findings here Simple iodine supplementation is not the answer to the question, as is it considered merely a co-factor in a range of causes. Others include, exposure to thyroid-disrupting compounds in the environment, drinking water or diet. Interest in this first appeared with the introduction of fire-retardant chemicals in many household items. The rates of hyperthyroidism seemingly increased with the introduction of these products. Findings here Cats are hyper-carnivorous and have lower activity of certain enzymes involved in both phase I and phase II detoxification pathways. These phases are responsible for breaking down toxic substances in the body (both internally produced and externally exposed). This therefore limits their ability to metabolise toxins. This poor metabolism of xenobiotics is thought to alter the structure and function of the thyroid gland, not only that but there are considerations that it too effects the elimination of T4 hormone, of which leads to high circulating levels. There is evidence which correlates high levels of toxic compounds with feline hyperthyroidism, these compounds are also higher than found in humans that the cats live with (suggesting issues in metabolism). There is a risk associated with commercial food that contain isoflavones and phthalates coming from soy and corn. Both of these compounds are known as endocrine disrupters. These vegetable substrates are detoxified by a particular pathway which is known to be slow in cats. Findings here Being an indoor cat is seen as a risk factor because of the exposure to persistent organic pollutants. Dust is a matrix collecting a range of volatile chemicals released from indoor products like flooring, textiles, furniture, and of course human skin (containing beauty or cleaning products). The heightened exposure is thought to be due to cat grooming behaviour – licking the dust off their coats and ingesting it. Findings here Certain flame-retardant compounds have also been found in commercial cat foods, and data has suggested that the cat liver struggles to metabolise these compounds. These PBDEs (polybrominated diphenyl ethers) contain bromine atoms which mimic iodine and so they may interact with thyroid binding proteins. Cats with hyperthyroidism have also demonstrated higher levels of PFAS which are polyfluoroalkyl substances which are found in products with grease repelling functions, like surface sprays, and floor polishes. Findings here Interestingly, there is a correlation between litter use and hyperthyroidism in cats. Those that use litter boxes more often, are more likely to receive a diagnosis. That along with receiving treatment for ectoparasites. Findings here BPA exposure has also been linked to hyperthyroidism in cats. As we know BPA is found in food, air and soil! Again, cats have a slower pathway in eliminating it. BPA binds to thyroid receptors, competitively displacing hormones. So, what can we do
The main forms of thyroid diseases are auto immune Thyroiditis (Hashimoto’s), Hypothyroidism (Non autoimmune), and Hyperthyroidism (Graves’ Disease). To find out more about Hypothyroidism, please click here Graves’ Disease is an autoimmune disorder that causes hyperthyroidism. As with us humans, your dog’s thyroid gland is located at the front of the neck. It is part of the endocrine system, butterfly-shaped and consists of two lobes located either side of the windpipe (trachea) that controls metabolism. Metabolic processes are activities that occur in cells, involving the release of energy from nutrients your dog eats. Microscopically, thyroid tissue is made up of two types of cells: follicular cells and parafollicular cells. Most of the thyroid tissue consists of follicular cells. The follicles store and secrete iodine –containing hormones called thyroxine. Thyroxine (T4) and tri-iodothyronine(T3). Thyroid hormones are important in the maintenance of normal, healthy activity levels of many different organs in the body: the heart, brain, liver, kidney and skin. All of which are vital for normal body function. The thyroid requires iodine to produce the hormones. Iodine is an essential trace element absorbed in the small intestine, it is an integral part of T3 and T4. Sources of iodine include iodised table salt, seafood, seaweed, and vegetables. However, too much iodine can actually activate thyroiditis, so if you supplement, (kelp being one of the most popular for dogs), please use with caution. Hyperthyroidism in dogs is a condition caused by the thyroid over producing thyroxine, increasing your dog’s metabolic rate to dangerous levels. It is much more common in older cats but when it does effect dogs it is usually serious. In some cases tumour growths in dogs can be benign and therefore easier to manage and may respond well to treatment, but malignant tumours can often spread to vital organs in the neck and risk further complication. ‘Hyper’ thyroidism (overactive) is rarer in dogs than ‘hypo’ thyroidism (underactive) and is usually a result from aggressive thyroid tumour called carcinoma (malignant) it begins in the epithelial tissue or the tissue that lines the gland. Thyroid tumours are commonly seen in middle aged to older larger breed dogs such as boxers, beagles, golden retrievers, and Siberian huskies. Hyperthyroidism can also be caused by an error in medications, which usually includes a synthetic form of thyroxine. An over correction of low thyroxine levels can sometimes result in hyperthyroidism. Graves’ disease in humans is often hereditary and between 25 and 50 percent of people have eye abnormalities, which are known as Graves’ ophthalmopathy. A small percentage of people with Grave’ disease develop a skin abnormality called pretibial myxoedema or Graves’ dermopathy. The primary cause of this disease is due to the increased metabolism, the body goes into overdrive that has an impact on the overall function of the body. Most commonly, the condition results in weight loss, despite an increase in appetite. Other possible signs and symptoms Hyperactivity Increased heart rate Swelling of the throat – goitre Anxiety Excessive panting, heat intolerance Increased thirst Increased urination Vomiting Diarrhoea Increased volume in stool Irritability or aggression Skin lesions, dry, greasy, matted coat Heart murmurs Congestive heart failure Cardiomegaly (enlarged heart) Dyspnoea (shortness of breath) Unfortunately, the majority of these aren’t necessarily specific to thyroid disease and signs and symptoms can vary from case to case. A visit to the vets as soon as you notice any signs is the best option. The checklist for thyroid disease A fresh and unadulterated fresh food diet Adrenal, liver, digestive immune and thyroid support Omega fats and antioxidants Vitamin deficiency test Diet for thyroid disease Fresh real food is advised for dogs with hyperthyroidism, preferably lightly cooked or raw. This is the most natural diet for dogs. Highly processed food is not recommended for dogs who have thyroid disease as they contain a very high percentage of carbohydrates, imbalanced omega 6-3 ratios and inappropriate ingredients, all of which cause inflammation in the body. They put huge pressure on the digestive system, pancreas and liver. Feeding whole fresh foods that provide a wide variety of nutrients will ensure a better chance of living a longer and healthier life. Hyperthyroidism has been linked to pet foods (raw commercially prepared) that include the thyroid glands of slaughtered animals. Exogenous hyperthyroidism, a result of excessive intake of thyroid hormones is rarely recognised but is the only other recognised cause. If you are concerned, contact your raw food supplier and ask them what parts they are using or home prepare your own food to be sure – for example chicken necks or trachea. Findings here Foods containing iodine should be avoided, some are listed here Processed food containing grains, cereal and soy Seafood Dairy products High amounts of poultry or beef Egg yolks Supplements such as kelp Seaweed Cruciferous Vegetables such as broccoli, cauliflower, kale and brussels sprouts may stop the thyroid from using iodine properly. Findings here Veterinary approach to thyroid disease ‘Outdated or incomplete information taught in veterinary schools perpetuates inaccurate screening for canine thyroid disorder, since many vets are still applying outdated diagnostic methods. Tests used to determine thyroid disease include T4, free T4, T3, free T3, TgAA, T4AA, T3AA, and TSH their usage and importance depend on the situation of the dog being tested. T4 alone is not a reliable method’ – Dr Jean Dodds, DVM – The Canine Thyroid Epidemic 2011 Treatment depends on the underlying cause. Hyperthyroidism is often treated with antithyroid drugs, which stop the overproduction of thyroid hormone. Depending on the severity, treatment may entail partial removal of the tumour or removal of the entire thyroid gland. Chemotherapy or radioactive iodine (I-131) treatment or medications to counteract the excess hormone levels in which case the dog will be on replacement therapy for the rest of his life. If left untreated the condition can cause heart and kidney failure. Therefore, the best approach to hyperthyroidism is to help prevent it by providing a wholesome natural diet and avoiding unnecessary chemicals or environmental hazards which are all
