What is Canine Hypothyroidism and What Causes It?

What is Canine Hypothyroidism and What Causes It?

Posted by Volhard Dog Nutrition on Apr 11th 2022

How much do you actually know about thyroid problems in dogs? Is your dog exhibiting:

  • Skin disease?
  • Neurological disorders?
  • Behavior issues?

If you're relatively new to the topic of thyroids, you're probably not aware of the connection between these common issues. Or that you should address the thyroid as a component of managing them.

In fact, we believe you should look at the thyroid for ALL chronic inflammatory conditions.

And that's why we want to talk about improving thyroid function. That way, you can help prevent and resolve thyroid problems in your dog.

The first thing you should know is that there are two main types of thyroid diseases.

  • Hypothyroidism: this is the most common condition in dogs. It happens when your dog doesn't produce enough thyroid hormones.
  • Hyperthyroidism: very rare in dogs. It happens when your dog produces too many thyroid hormones.

Most neurologic, skin, ear, and joint conditions have a significant hypothyroid component, and many go undiagnosed. Dogs with seizures as well as phobias, anxiety, or depression also need to have a full thyroid panel. The goal is to catch hypothyroidism signs early, which could be the key to intervention for other disease relationships. We have found the most effective ways to understand hypothyroidism disease relationships are:

  • Muscle testing
  • Prioritization protocols
  • Effective dosing therapies

What is Canine Hypothyroidism?

Hypothyroidism is a typical canine endocrine disorder resulting in the hyposecretion of the thyroid hormone in the thyroid gland, located close to the larynx. When affected, the thyroid gland gradually shrinks and cannot produce the necessary amount of thyroid hormone. As the secretion of the thyroid hormone decreases, the canine metabolism gradually slows down, thus causing several symptoms such as lethargy and hair loss.

Canine hypothyroidism distinguishes itself into four syndromes:

  • Lymphocytic thyroiditis (primary form)
  • Atrophic hypothyroidism (primary form)
  • Pituitary-dependent hypothyroidism (secondary form)
  • Euthyroid sick syndrome (secondary form)

Types of Canine Hypothyroidism

#1: Lymphocytic Thyroiditis

Lymphocytic thyroiditis is an immune-mediated response to the infiltration of lymphocytes (i.e., a type of white blood cells produced by the immune system). Lymphocytic thyroiditis is the most common type of canine hypothyroidism. Causes that precipitate the onset of lymphocytic thyroiditis are the body's response to medications, vaccinations, viral infections, and heavy metal toxicity from water or food sources. The most telling signs of lymphocytic thyroiditis are the elevation of the T3 and T4 autoantibodies on the thyroid profile.

#2: Atrophic Hypothyroidism

Atrophic hypothyroidism occurs when the thyroid gland becomes atrophied, and glandular tissues called the parenchyma are replaced by adipose tissue (i.e., fat). Atrophic hypothyroidism manifests itself through the decrease of synthesis and secretion of the T3 and T4 autoantibodies on the thyroid profile.

#3: Pituitary-Dependent Hypothyroidism

Pituitary-dependent hypothyroidism is caused by the pituitary gland's insufficiency in secreting thyroid-stimulating hormones or TSH. Through this hormone, the pituitary gland communicates to the thyroid gland the need to create and release more thyroid hormones into the bloodstream. Several factors can determine an impaired pituitary gland activity, such as:

  • Drug reactions
  • Illnesses
  • Malnutrition
  • Congenital malformations
  • Tumors
  • Infections
  • Hemorrhage involving the pituitary gland

Low levels of TSH, coupled with low resting levels of TT4 and FT4 (corrected by TSH stimulation), are the most telling sign of pituitary-dependent hypothyroidism in your dog.

#4: Euthyroid Sick Syndrome

The euthyroid sick syndrome calls for more attention because its symptoms can be confused with other diseases. In many severe or chronic diseases, such as debilitating diseases, kidney failure, diabetes mellitus, and hyperadrenocorticism (i.e., Cushing's disease), the TT4 and FT4 levels decrease in order to counter the reduced caloric intake. A drop in TSH might point towards hypothyroidism when, in reality, it is not the thyroid gland that's suffering. By correcting or controlling the aforementioned diseases, your dog's thyroid will gradually return to normal.

Canine Hypothyroidism Symptoms

The range of canine hypothyroidism symptoms is broad and comprehensive. Most dog breeds manifest hypothyroidism symptoms around the ages of four to six, whereas giant breeds exhibit symptoms from an earlier age, at two or three years of age. Furthermore, hypothyroidism symptoms require anywhere between six months to a year to become manifest. However, current research pointed out behavioral changes as the earliest sign of hypothyroidism in dogs. Other symptoms that dogs with hypothyroidism regularly exhibit are:

  • Weight gain;
  • Lethargy;
  • Slow hair growth;
  • Dull, dry coat;
  • Bradycardia (i.e., slow heart rate);
  • Infertility;
  • Bilateral alopecia (i.e., hair loss located in the trunk);
  • Hyperpigmentation;
  • Skin thickening.

Any hypothyroidism diagnosis requires a careful assessment of the dog's overall health since this disease shares multiple of its symptoms with other diseases. Therefore, ensure that you avoid overdiagnosis before starting your dog on a treatment for hypothyroidism.

Breeds Predisposed to Hypothyroidism

The breeds with higher chances of developing hypothyroidism are:

  • Dachshunds
  • Golden Retrievers
  • Irish Setters
  • Schnauzers
  • Dobermans
  • Cocker Spaniels
  • Airedale Terriers

Diagnosing Hypothyroidism

Diagnosis modalities such as a chemistry profile, complete blood count (CBC), and thyroid function screening can unearth hypothyroidism in dogs with no preliminary symptoms and confirm the disease in dogs with visible symptoms. The most common hypothyroidism tests available are: total T4, free T4, total and free T3, and TGAA (i.e., Thyroglobulin Autoantibody).

The reason behind the various testing modalities lies in hypothyroidism's array of symptoms. Hypothyroidism is a regularly overdiagnosed canine disease, which is why a correct diagnosis requires extra attention to symptoms and flawless interpretation of test results. Each hypothyroidism test responds to a specific suspicion of this disease.

The most telling signs of hypothyroidism present in test results are normocytic, normochromic, nonregenerative anemia (40%-50% of cases), as well as hypercholesterolemia (80% of cases). The latter plays a crucial role in the early detection of hypothyroidism since cholesterol levels quickly respond to thyroid abnormalities. Other imbalances, such as high triglycerides, alkaline phosphatase, and creatine kinase, are also considered in a hypothyroidism diagnosis.

The TT4 (i.e., total thyroxine) test is an efficient early screening test for hypothyroidism, with a diagnostic sensitivity of 90%. The TT4 test measures the main thyroid hormone in a blood sample. While T4 levels within range are a telling sign of a healthy thyroid, subnormal basal T4 levels do not automatically mean a hypothyroidism diagnosis; your dog might be healthy or suffering from a disease with symptoms similar to hypothyroidism. Therefore, the TT4 test is more appropriate to help differentiate between euthyroid dogs and hypothyroid dogs. The free T4 (i.e., free thyroxine) test, with its increased sensitivity, will help determine the hypothyroidism type your dog is suffering from.

Another auxiliary method to strengthen your dog's hypothyroidism diagnosis is determining his TSH concentration. Normal to high concentrations point towards a primary hypothyroidism diagnosis, whereas high TSH concentrations point towards dogs with the euthyroid sick syndrome. Comparing TSH concentrations with TT4 and FT4 levels will help deliver a more hypothyroidism diagnosis.

How to Improve Thyroid Function

There are ways to dramatically improve thyroid hormone use and enhance healing. These include:

  • Enhancing critical thyroid cofactors
  • Reducing fluoride exposure
  • Mitigating EMF exposure
  • Regular detoxification (especially from chemicals and heavy metals)
  • Treating co-infections
  • Low dose natural hormone replacement
  • Glandulars
  • Homeopathy

And that's just a few things you can do to help a dog with thyroid problems. Let's look at some of these in more detail.

How to Treat Hypothyroidism in Dogs

Modern medicine knows numerous ways of treating hypothyroidism, the most common medical treatment being Soloxine. But dogs are not only in need of reactive treatment modalities; they also require a healthier lifestyle and a healthier diet in order to keep their thyroid glands healthy.

#1: Treatment With Soloxine

Soloxine is a synthetic hormonal drug that acts as a replacement for the T4 hormone. Most dogs receive two doses of Soloxine per day, although the dosage can be reduced to one dose per day as the T4 hormone levels gradually return to normal. Most veterinarians recommend thyroid response profiles every 10th week to ascertain the medicine’s effectiveness. Once T4 levels are back to normal, thyroid profiles can be reduced to a yearly occurrence.

#2: Acupuncture

Veterinarians recommend acupuncture as an auxiliary treatment to treating hypothyroidism. When paired with other treatment modalities, acupuncture allows a reduction in Soloxine supplementation. However, this treatment modality is not enough to cure hypothyroidism, nor should it replace proper medication.

#3: Feeding a Natural Diet

Aside from medicine, what your dog requires in his battle with hypothyroidism is a hydrated, natural diet to support the medication and ensure his thyroid gland's health.

How Food Affects Thyroid Problems in Dogs

When it comes to improving your dog's thyroid function, you need to change what your dog is eating and drinking. Some of the first changes you should make (if you haven't already) are adding:

  • Fluoride-free filtered water
  • Fermented foods
  • Exercise in nature
  • High-quality natural foods (start with gluten-free and then identify top inflammatory sensitivities)

These changes can make a huge difference in the quality of life for your dog and overall health and vitality.

You also need to address:

  • The microbiome (the community of bacteria and other microorganisms living in and on your dog)
  • Digestion
  • Absorption of key nutrients

The gut and the entire microbiome are crucial for the immune system. Taking care of them will help with any underlying infections and systemic inflammation.

The gut and microbiome also directly relate to the degree of brain inflammation. And this can affect behavior and seizures. Science has proven there's no separation; a leaky gut equals a leaky brain, even in cases that affect the central nervous system. You still need to address gastrointestinal pain and inflammation. If your dog has ulcers, it can dramatically lower tremor or seizure thresholds. And Helicobacter pylori is a stomach pathogen that may be at play in more cases than we know.

Food sensitivities will reduce once you start managing your dog's digestive tract. Some steps that are important for overall health include:

  • Regular fasting
  • Scheduled gentle detox (We will talk more about detox later on)
  • Liver support

Incorporating some natural fibrous nutrients is also an excellent start:

  • Asparagus
  • Green beans
  • Beetroot
  • Cooked broccoli
  • Cooked Brussels sprouts
  • Carrots
  • Celery (also good for eradicating retroviruses – go slowly)
  • Cucumber
  • Garlic
  • Lettuce
  • Mushrooms
  • Cooked spinach

It can also be very beneficial for the prevention of early hypothyroidism symptoms to add small to moderate amounts of:

You also want to research and avoid the top glyphosate-containing foods. You may find it surprising that most kibbles are likely contaminated. A lot of these vegetables can be found in the Volhard Rescue Diet, minimizing what you need to add every day.

Time to Detox

Our favorite detoxifiers are milk thistle and homeopathy or homotox­icology drainage. Later, when you stabilize your dog's thyroid, you can introduce more detoxifi­cation. Other gentle and effective detoxifiers include:

  • Thyroid flower essences
  • Low potency homeopathy (such as Thyroidinum 6C,12C, 6X or 12X or Calcarea carbonica 30C)
  • Glandular supplements (Standard Process Thytrophin PMG or Thyro Complex and other cofactor combinations)

Herbal combinations may be an excellent place to start if there are severe symptoms. Try herbs such as:

  • Ashwagandha
  • Coleus forskohlii
  • Turmeric

They can be very beneficial. Mushrooms may also play a key role in immune support and thyroid function. When detoxing, you also want to support general immune functions and treat co-infections. This is critical as significant symptoms may present when detoxification processes are underway.

And don't forget about inflam­mation. It can show up anywhere in or on the body during the healing process. If this happens, don't stop but get experienced advice. Another reason to use Rescue as it is an anti-inflammatory, hypoallergenic diet and has herbs and other ingredients to battle inflammation issues.

There's evidence that the cortisol pathway may need support in many hypothyroid cases. I find low doses of natural hydrocortisone assist the body, and it dramatically improves the quality of life for those with inflam­matory cascades. (Especially in neurologic and skin cases.) The key is to go slow and steady and pay attention; only you know your pet best.

A Parting Reminder

Although it is the primary canine endocrine disorder, hypothyroidism does not have to affect your dog's well-being. With the proper detection methods, treatments, and diet, your dog's thyroid issues can be managed. In the meantime, you, the dog parent, can shorten your dog's recovery by keeping him away from EMF (i.e., electromagnetic field) sources such as WiFi and cell phones. Furthermore, try to limit your dog's leash time since research has found a correlation between dogs pulling on their leash and hypothyroidism. For more advice on dog nutrition, health, and training, make sure that you contact us and check out our blog!


To help more dog parents discover why, what, and how to feed their dogs the healthiest of foods, Volhard Dog Nutrition and its nutritionists are now offering online consultations! Speaking to a Volhard nutritionist will help you understand the inseparable relationship between healthy food, a healthy body, and a healthy mind. If you're interested in contacting one of our Volhard nutritionists, don't hesitate to check out our consultation page!

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