The Ultimate Guide to Graves Disease in Pets

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.

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Findings Here


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 cheapest option, this may be the first port of call made by your veterinarian, but it’s important to understand that it does not cure, and there are various potential side effects associated with the drugs used in this approach, including anaemia, high body temperature spikes, rapid and extreme weight loss, and vomiting.

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Surgical Removal

A less common, but still practiced approach to hyperthyroid treatment, is having a thyroidectomy – removal of the thyroid gland entirely. This would cure your pet of Graves Disease, but is an invasive procedure, which is no more successful than the aforementioned Radioactive Iodine Therapy, and could risk damage to other glands in the neck area, such as the parathyroid glands, which are responsible for stabilising blood calcium levels.

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Findings Here

Dietary Changes

Those suffering with Graves Disease should have their diet reviewed; we will cover more on this min more depth next in this blog. Milder cases of Graves Disease may be cured through dietary therapy, but more severe cases would likely only offer conservative management of the disease.

The aim in the dietary review, is to limit the amount of iodine in the diet. Iodine is an essential ingredient nutrient, and it is incredibly important that the correct amount for the individual animal being treated, is consumed so as not to have long term effects on other parts of the body due to iodine deficiency.

You can read more about iodine, and why it is important in the correct amounts, in our blog here!

Supporting the Body Naturally

There are many ways we can be supporting our pets’ bodies as they battle with Graves Disease, or while they wait to undergo treatment.


When you are feeding a pet with Graves Disease, it is important to aim for a fresh option, with whole foods, eliminating any processed foods from the diet. Processed foods like kibble usually contain synthetic vitamins and minerals, which can lead to excess of some vitamins and minerals, or deficiencies in some vitamins and minerals in the body. As a consumer, we do not know exactly what is in each bag, each bowlful, each mouthful – it’s impossible to know! Feeding a fresh diet eliminates this risk, and allows you to control what goes into your dog or cat’s diet! A bespoke recipe may be required for your pet with Graves Disease – a recipe is included with your consultation, so book in today!

With thyroid diseases, we need to take a look at the amount of iodine being consumed, and adjust the levels as necessary depending on the individual pet’s current health status. Those with hyperthyroidism require a very minimal amount of iodine in their diet – consumption of too much iodine can cause major problems as the thyroid uses iodine to make it’s hormones. Too much iodine would cause further overproduction of the hormones, which is already an issue in those with Graves Disease! Avoid sources such as:

  • Seaweeds/kelp (116-6636mcg per 5g)
  • Cod (186mcg per 5g)
  • Oysters (109mcg per 100g)

And limit sources such as:

  • Eggs (26mcg per egg)
  • Beef liver (16mcg per 100g)
  • Prawns (15mcg per 100g)

The final part of tweaking the diet for those with Graves Disease, is ensuring you are on top of any food sensitivities. Hyperthyroid diseases may be worsened by eating allergens due to the strain they put on the body, and potential for delayed effects and responses by the body. Typically, especially in humans, gluten and dairy allergies are major triggers for flares of Graves Disease. Many dogs are intolerant to dairy, so it’s imperative that all dairy is removed from the diet, and gluten is also avoided. Gluten-containing ingredients are not generally recommended for our canine or feline companions regardless, as they’re carnivorous canids, so would struggle to digest these items.

As Graves Disease is an autoimmune disease, we want to keep the gut as healthy as possible as this is where most of the immune system lays. A health gut contributes greatly to a healthy immune system, which reduces the chance of autoimmune diseases developing, or existing autoimmune diseases to worsen.

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Findings Here

Supplements and Important Micronutrients

Now onto supplements. First we will look at gut health. Gut health, as previously mentioned, is essential in reducing the onset of, and effects of autoimmune diseases. You can read more about the link between autoimmunity and leaky gut here, and here.

Gut Heath: So how can we help keep the gut healthy? Some simple supplements are great for this – a mucilage herb for healing, and a good, high quality and clean probiotic to help the gut microbiome flourish, allowing the body a better chance of healing. These supplements are very important in Graves Disease patients, as many have Small Intestine Bacterial Overgrowth (SIBO), Leaky Gut, or other problems with the gut microbiome.

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Mucilage herbs include slippery elm, marshmallow root, and deglycyrrhizinated liquorice. A soil based probiotic would be ideal as these are the most clean available, and most therapeutic. Some owners use kefir for their dog’s probiotic, however if this is what you choose, aim for a kefir water, as traditional kefir is dairy based (albeit fermented). Our mucilage and probiotic mix, Gut Guardian, may be the perfect supplement for your canine companion – and you can purchase it here!

Selenium is one of the important micronutrients for all mammals, and has great effects on those with Graves Disease, as studies show that it reduces symptoms, and reduces the rate of potential relapse of Graves Disease. It has also been proven by ophthalmologists, that selenium reduces the risk of eyesight loss due to Graves Disease. Chicken, fish, turkey, pork and mushrooms are all great sources for our furry friends!

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Findings Here

Lemon Balm is a non-toxic herb which can be used in dogs, cats, horses and other mammalian species. It can be a powerful part of heloping your pet cope with Graves Disease, as it is known to protect the heart from potential damage caused by the disease, and also to inhibit the production of Thyroid Stimulating Hormone (TSH) which is what promotes production of T3 and T4 hormones.

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Findings Here

Those this Graves Disease, often have a Vitamin B12 deficiency. This is partly what causes muscular weakness and lethargy in pets with Graves Disease. Our supplement, Gut Guardian, contains B12 alongside the other beneficial ingredients. Vitamin B12 also aids absorption in the gut, so it’s a win-win! Other sources of Vitamin B12 include salmon, beef, shellfish, fish, chicken, lamb and pork.

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A study suggests that Vitamin D deficiency may also increase the chances of a Graves Disease relapse, post treatment. Vitamin D is said to be useful for both hypothyroid diseases, and hyperthyroid diseases.

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L-Carnitine is an essential amino acid, which is heavily involved in metabolism. Studies show that it blocks thyroid hormones from entering some cells in various parts of the body, which brings some relief of symptoms to those with Graves Disease, and also helps protect other organs from secondary infection.

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Upping the Omega 3 is also important, as with many health conditions, the anti-inflammatory effect of omega 3 is great to help support healthy immune function. autoimmune diseases can go into remission if the immune system is correctly modulated, and the gut is kept healthy, and free from inflammation. Omega 3 also decreases oxidative stress, which helps protect major organs in the body from secondary infection. Oily fish, fish oils, and algal oils are great sources of omega 3. Raw eggs are also excellent, though we need to be mindful that they’re relatively high in iodine, so should be given sparingly.

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There are a few lifestyle changes which can help those with Graves Disease. These simple changes can help the pet in so many ways.

Switching your flea and worm treatments to natural alternatives, and regularly testing for intestinal parasites can help not only keep your pet from the potential neurological dangers of over the counter or prescribed products, but also eliminate the risk of such products damaging the gut. As mentioned above, gut health is incredibly important when dealing with any autoimmune disease.

You can learn more about switching to natural prevention here!

Increasing your pet’s exercise may help reduce secondary health concerns such as diabetes. Studies also show that structured exercise can help reduce relapses in Graves Disease sufferers post treatment. When it comes to increasing exercise, this is by no means encouraging strenuous exercise, but regular walking is essential – it also benefits the next, and final point about stress!

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Findings Here

Finally, reducing stress in your pet’s life is very important. Since one of the symptoms of Graves Disease is an increased heart rate, and secondary cardiac disease is very possible if your pet’s Graves Disease is not treated, it is ever so important to promote calmness and reduce stress in your pet’s life. Regular, suitable exercise, teamed with lots of chances to sniff the environment, could be life changing for a pet with Graves Disease. Studies show that stress encourages the onset of relapses in those with Graves Disease, and other hyperthyroid diseases.

You can read more about the link between stress, and disease in pets here.

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Findings Here

We hope this comprehensive guide has helped you look at alternative avenues to a healthier, and more comfortable life for your pet with Graves Disease. If you feel some tailored 1-2-1 help would benefit you and your pet, please don’t hesitate to book in with one of our team for a consultation. Our Personalise Package would be ideal for you!

Team MPN x

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