Hypothyroidism in dogs isn’t always obvious. You might consider getting your dog tested if you saw some better-known symptoms … like sluggishness, weight gain or hair loss. Those are the signs your conventional vet looks for too. But it’s not always that obvious …
This means your vet may never include thyroid testing in your dog’s blood work. And when your vet does test, she might not do the right tests. That’s a really important mistake many vets make.
So in this post you’ll read about some signs to watch for, what tests you need to ask for, and some effective natural ways to help your hypothyroid dog. But first … what’s the thyroid and what does it do?
The thyroid is a little butterfly-shaped gland at the base of the neck. Its beside your dog’s windpipe, near the voice box.
The thyroid’s job is to regulate the metabolism of the body’s cellular functions. It produces hormones like thyroxine (T4) and triiodothyronine (T3). These hormones affect energy levels, temperature, hair, skin, weight. The thyroid’s an important gland. But it doesn’t work alone. It’s part of the hypothalamus-pituitary-thyroid (HPT) axis.
The HPT Axis
The thyroid works in balance with two other glands … both in the brain. These are the pituitary gland and the hypothalamus. Together with the thyroid … these glands form the hypothalamic-pituitary-thyroid (HPT) axis (1). The HPT axis drives the set point of thyroid hormone production …
- The hypothalamus secretes a hormone called thyrotropin-releasing hormone (TRH).
- TRH stimulates the pituitary to release thyroid-stimulating hormone (TSH).
- TSH triggers the thyroid gland to secrete T4 and T3 (mainly T4, which converts to T3 in the liver and gut).
So … when this process isn’t working properly, hypothyroidism can result.
What Is Hypothyroidism?
Hypothyroidism is the most common endocrine or glandular disorder in dogs. It happens when the thyroid doesn’t produce enough T4 … which lowers your dog’s metabolic rate. There are two reasons for this problem.
Primary Hypothyroidism In Dogs
Primary hypothyroidism is usually an autoimmune disease – autoimmune thyroiditis or lymphocytic thyroiditis.
This happens when your dog’s body mistakes its own thyroid gland and hormones as foreign threats. Then the body produces antibodies to attack and destroy the thyroid gland cells. These attacks cause secondary scarring of the tissue … and that leads to loss of thyroid function.
Dr Jean Dodds DVM is well known as an expert on thyroid issues in pets. According to Dr Dodds, nearly 90% of hypothyroidism in dogs is autoimmune.
Secondary Hypothyroidism In Dogs
This is usually a problem with the hypothalamus-pituitary-thyroid axis (HPT) mentioned earlier. When the HPT isn’t working properly, the thyroid doesn’t get the signals it needs.
If the hypothalamus doesn’t produce enough thyrotropin-releasing hormone (TRH) … the pituitary doesn’t get its “orders.” And then the pituitary doesn’t produce enough thyroid-stimulating hormone (TSH). So it doesn’t tell the thyroid what to do.
This doesn’t mean the thyroid itself is damaged. Dr Marty Goldstein DVM has a good analogy for this.
“If you buy a new toaster and the electrical plug got cut off, you wouldn’t be able to toast your bread, even though there’s nothing wrong with the toaster itself.”
In the same way, your dog’s thyroid can be normal … but doesn’t get the messages it needs to work properly. That’s secondary hypothyroidism.
Can Dogs Be Hyperthyroid?
The opposite of hypothyroidism is hyperthyroidism and it’s very rare in dogs. (It’s much more common in cats.) Hyperthyroidism means the body produces too much T4. This increases the metabolism … sending the body into overdrive. It can cause weight loss, anxiety, diarrhea and more.
Again, it’s very rare in dogs. And when it does happen, it’s often due to thyroid cancer. Or it may happen if your dog gets too much medication for hypothyroidism.
Dog Breeds Prone To Hypothyroidism
Some dogs may have a genetic link to hypothyroidism. Breeds prone to hypothyroidism include …
- Golden Retriever
- Doberman Pinscher
- Irish Setter
- Miniature Schnauzer
- Cocker Spaniel
- Airedale Terrier
If you have one of these breeds, you’ll want to watch your dog for signs of the disease. There can be other causes too.
Causes Of Hypothyroidism In Dogs
The Merck Veterinary Manual says the two most common causes of primary hypothyroidism in dogs are:
- Lymphocytic thyroiditis. (This means it’s immune-mediated disease.)
- Idiopathic atrophy of the thyroid gland. (Idiopathic means they don’t know what causes it.)
Merck says secondary hypothyroidism in dogs is usually due to a large tumor that takes space away from the pituitary. This can cause malfunction and stop it from producing hormones.
But these explanations don’t really explain the causes. Holistic vets will give you some different answers.
What Can Lead To Hypothyroidism
Let’s look at what a few holistic vets have to say …
1. Drugs, Vaccines And Food
Dr Marty Goldstein DVM blames these pharmaceutical products (in addition to genetics):
- Chemical flea, tick and heartworm products
- Vaccines – remnants of tissue cultures and other chemicals in vaccines
Vaccines in particular can trigger many kinds of autoimmune disease. Heavy metals and other ingredients in vaccines are especially dangerous. When you inject something into the body, you bypass skin and mucous membranes that normally form a barrier against toxins.
Dr Richard Pitcairn DVM PhD believes several factors cause immune disorders like hypothyroidism:
“All of these things have greatly weakened the immune system of animals over several generations” says Dr Pitcairn.
2. Herbicides And Pesticides
According to Dr Patricia Jordan, herbicides and pesticides can be another big problem when it comes to hypothyroidism in dogs. Pesticides and herbicides contaminate our food, water and air.
Dr Jean Dodds warns that choke, prong or chain collars can do permanent damage to the thyroid. Even a hard braided leather collar can cause a problem. Trauma and sudden pressure from a dog who pulls or lunges on leash can damage the thyroid … as well as the neck and trachea.
It’s much safer to use a harness to walk your dog. Make sure the front of your dog’s harness sits across the chest, not his neck. This can help prevent hypothyroidism in dogs.
4. Environmental Toxins
Dr Tamara Hebbler CiHom DVM (“Doctor AMara”) believes many environmental toxins cause hypothyroidism in dogs:
- Too much estrogen in the body (often caused by toxins like plastics and pesticides)
- Electromagnetic frequencies (EMFs)
- Heavy metal toxicity
- Fluoride in drinking water – which ends up in packaged foods as well
Just about any chemical in your dog’s environment can cause endocrine disorders. Here are a few that research shows can impact the thyroid.
- BPA (bisphenol-A) from plastics (water bottles, food containers, canned food liners) (3).
- Phthalates – bottled waters, food storage, food wraps, cosmetics … and many dog toys! (4
- PCBs (polychlorinated biphenyls) – still in the environment even though banned in the 1970s (5).
- PBDEs – flame retardants.
- Triclosan – antibacterial agent in soaps and creams (6.
- Phenols – in detergents, pesticides and plastics (7.
- Perchlorate* – in soil and groundwater. Also found in milk, produce, bottled water, wine and beer (8).
*In the 50s, perchlorate was used to treat hyperthyroid cases. So that tells you why it might cause hypothyroidism in dogs!
So … you can see that many products in your dog’s environment could disrupt his thyroid function. Dr Tamara Hebbler estimates that 80-90% of urban middle-aged dogs have some hypothyroidism.
Signs Of Hypothyroidism In Dogs
According to Dr Jean Dodds … classic hypothyroid symptoms don’t show up until 70% of the thyroid is already damaged. So it’s important to recognize the early symptoms of thyroid disease in your dog.
These are the classic symptoms of hypothyroidism in dogs that you may know about:
- Weight gain
- Hair thinning or loss
- Bad skin
- Cold intolerance
But there are some other early symptoms that might suggest hypothyroidism.
Early Symptoms Of Hypothyroidism
These are some of the less obvious symptoms mentioned earlier.
A key early symptom of thyroid disease is a behavior issue … like grumpiness, anxiety, fear or phobia, aggression, or depression. If your dog shows these problems, don’t assume it’s “just a behavior issue.” It could be caused by hypothyroidism, so get your dog’s thyroid tested.
A change in your dog’s appearance could also mean thyroid problems. Weight gain (especially without a diet change) is one possibility. But your dog’s face could even look different! Dr Dodds recommends taking regular photos of your dog so you can see the changes. You may see your dog’s brow look furrowed. Or there could be a cleft above the eyes.
These may include things like slow healing wounds, poor immune function, dry or dull coat, change in coat color, seizures or tremors (9)
Hypothyroidism can be an underlying element in many other chronic health issues. Consider the thyroid if your dog has …
- Skin issues
- Neurological issues (9)
- Ear problems
- Joint conditions
- Frequent injuries
- Digestive issues like acid refux or regurgitation
- Dry cough
- Leaky gut syndrome
- Acquired (not hereditary) laryngeal paralysis
- Eye problems – cataracts, cherry eye, corneal ulcers
- Premature aging changes – vision or hearing loss
- Lipomas, skin tags
- Heart issues
- Blood sugar issues
- REM Behavior Disorder
- Other autoimmune endocrine disorders like Addison’s, diabetes, IBS
- Other autoimmune non-endocrine problems, like autoimmune hemolytic anemia
If your dog has one of these issues, testing for hypothyroidism is a good idea. Don’t let your vet talk you out of it.
Testing For Hypothyroidism In Dogs
If you ask a conventional vet to test your dog’s thyroid … most of them will just get a T4 test. But that’s not enough …
Why The T4 Test Alone Isn’t Enough
All holistic vets will tell you the T4 test alone is useless. T4 can be affected by many other factors. Even the Merck Veterinary Manual says … hypothyroidism is “one of the most over-diagnosed diseases in dogs.” And that’s likely because the diagnosis of hypothyroidism is often based on T4 alone. Countless dogs are diagnosed with hypothyroidism … and medicated, based on T4.
Dr Dodds says T4 is inadequate because it …
- Over-diagnoses hypothyroidism – especially with non-thyroidal illness or use of certain drugs
- Doesn’t detect autoimmune thyroiditis
Thyroid Tests To Ask For
Dr Dodds recommends a full thyroid panel to diagnose hypothyroidism in your dog:
- Total T4 – Total amount of T4 (thyroxine) hormone that circulates in the blood. More than 99% of T4 hormone is “bound,” meaning it attaches to proteins in the blood and never reaches the tissues.
- Free T4 – Free T4 level tells the pituitary gland whether it needs to produce more TSH.
- Total T3 – both the bound and unbound forms of T3 circulating in the blood. Serum T3 alone is not accurate as it’s often influenced by secondary non-thyroidal illness.
- Free T3 – free T3 level tells the pituitary gland whether it needs to produce more TSH.
- Canine Thyroglobulin Autoantibody (TgAA) – dogs with autoimmune thyroiditis will have elevated TgAA.
Hemopet has added a new measurement as well. This is the T4:Free T4 ratio. It helps distinguish between a thyroid disorder and another underlying disease.
Conventional Drugs For Hypothyroidism
If your dog’s tests show he’s hypothyroid, your conventional vet will want to prescribe a synthetic thyroid hormone called levothyroxine. The FDA says “there is no cure for hypothyroidism.” They say this drug is your only option. But this isn’t true! There are many dogs whose hypothyroidism can be managed or even reversed with the natural remedies described below.
Levothyroxine Side Effects
Be aware of these known side effects of levothyroxine, and contact your vet if you see any of them in yoru dog.
- Not eating
- Skin problems – red, inflamed skin
- Decreased activity level
- Increased drinking and urination
- Increased activity level
Your vet will need to also need monitor your dog’s reaction to dosing. Too much medication can cause thyrotoxicosis. If you see some of these signs when your dog’s taking levothyroxine, your dog’s dose will need lowering.
- Rapid pulse
- Increased drinking and peeing
- Weight loss (despite increased appetite
Don’t use this drug if your dog has Addison’s disease … or in breeding, pregnant or nursing dogs.
Instead of immediately resorting to synthetic hormone medication, there are many natural therapies you can try first.
7 Natural Solutions For Hypothyroidism In Dogs
It’s best to work with your holistic vet, herbalist or homeopath for professional guidance with this chronic condition. Find an expert rather than trying these remedies by yourself.
Many herbs play an important role in supporting thyroid and immune function. Here are a few possibilities.
- Ashwaganda (10)
- Coleus forskohlii (Forskolin) (11)
- Schisandra Berry (12)
- Bladderwrack (13)
- Kelp (14)
Dosing of these herbs must be individualized for your dog. Consult your herbalist or a holistic vet experienced in herbs.
Many homeopathic remedies can support hypothyroidism in dog. But again … you’ll need to work with an expert practitioner. An experienced homeopath will analyze your dog’s individual symptom and health picture.
Homeopathic veterinarian Dr Jeff Feinman BA VMD CVH estimates there are more than 60 homeopathic medicines that are associated with hypothyroidism treatment in dogs.
“It really is individual,” says Feinman. “So one medicine that we treat one animal with may have nothing to do with what the other one has.”
3. Nutraceuticals And Glandulars
Your holistic vet may prescribe nutraceutical or glandular supplements. Some supplements she may consider are iodine, selenium or zinc. These nutrients all support thyroid health. Selenium and zinc help convert T4 to T3 and iodine is important for proper thyroid function.
But again, talk to your vet about your dog’s individual needs. Not every dog needs all these nutrients!
Here are some commonly used supplements you can ask your vet about for hypothyroidism in dogs. Many holistic vets like the products from these companies.
Standard Process (only sold through practitioners)
The supplements below contain natural dessicated bovine or porcine thyroid. These can boost your dog’s thyroid health and may avoid the need for synthetic hormone drugs.
- Ancestral Supplements Grass-Fed Natural Dessicated Beef Thyroid (also contains liver)
- Nutri-Meds Bovine Thyroid Health
- Nature-Throid (prescription)
- Armour Thyroid (prescription)
You may also want to ask your holistic vet about doing a Metabolic Nutritional Analysis via Smith Ridge Veterinary Center. Once the analysis is done, they’ll make up a glandular supplement tailored to your dog’s results. (Disclosure: This therapy reversed my own dog’s hypothyroidism.)
4. Traditional Chinese Veterinary Medicine (TCVM)
Like homeopathy, Traditional Chinese Medicine takes a “whole patient” approach to thyroid disease (15). Your TCVM vet will identify any imbalances or deficiencies in your dog. Treatment will usually involve a combination of food energetics, Chinese herbs, and acupuncture.
So you’ll need to find a TCVM practitioner to work with on an individualized approach for your dog’s hypothyroidism. You can look for a TCVM vet at The Chi Institute’s directory.
Even though this is the last point, diet is probably the most important aspect of your dog’s health … no matter what condition you’re dealing with. Try to feed your dog a fresh, whole food, preferably raw-meat diet. And if your dog has hypothyroidism, there are many foods you can add to support his thyroid health.
Vegetables should be pureed or mulched, or lightly steamed for digestibility.
A note about cruciferous veggies …
Some believe that dogs (and people) with thyroid problems should avoid cruciferous veggies … like kale, cauliflower and broccoli. This is because they are “goitrogenic.” That means they can cause the thyroid to enlarge.
Dr Jean Dodds has commented on this issue. She says …
“Erring on the side of caution is prudent but, in this instance, the antioxidant and vitamin K benefits definitely outweigh the risks. The goitrogenic properties in these green leafy vegetables are minute and should not cause concern if fed in moderation.”
Other Helpful Foods
Dr Hebbler suggests small amounts of the foods below may help prevent early hypothyroidism symptoms in your dog:
Because of chemicals in the water supply … always make sure you give your dog fresh spring or filtered water.
7. Other Support For Hypothyroid Dogs
Here are a couple of other changes that can support your dog’s overall health.
Remember how many chemicals can affect your dog’s thyroid? So to help your dog’s thyroid and overall health … consider a regular detox. This will support all of your dog’s organs … including the thyroid. For information on detox, check out Dr Dee Blanco’s advice on detoxing your dog.
Manage EMF Exposure
Most holistic vets agree that electromagnetic frequencies contribute to many chronic diseases. You can reduce your dog’s EMF exposure by:
- Using a wired internet source instead of Wi-Fi
- Turning off Wi-Fi at night and when you leave the house
- Turning off your cellphone at night, and keeping it outside the bedroom
- Keeping phones in airplane mode when not in use
- Keeping cellphones at least 3 feet away from your dog at all times
- Removing cordless phones from your home
- Not letting your dog sit too close when you’re on your computer
Plenty of good exercise supports your dog’s overall health. If you live in a city, try to get out into nature with your dog sometimes. Even just a weekend outing will be therapeutic for both of you!
This information can help you find natural solutions for your dog’s hypothyroidism. There are lots of things you can before resorting to pharmaceuticals!
- Ortiga-Carvalho T, Chiamolera M, Pazos-Moura C, Wondisford F. Hypothalamus-Pituitary-Thyroid Axis. PubMed.Gov. PMID: 27347897 DOI: 10.1002/cphy.c150027
- Gasnier C, Dumont C, Benachour N, Clair E, Chagnon MC, Séralini GE. Glyphosate-based herbicides are toxic and endocrine disruptors in human cell lines. PubMed.Gov.
- Moriyama K, Tagami T, Akamizu T, Usui T, Saijo M, Kanamoto N, Hataya Y, Shimatsu A, Kuzuya H, Nakao K. Thyroid hormone action is disrupted by bisphenol A as an antagonist. J Clin Endocrinol Metab. Nov 2002. 87(11):5185-90.
- John D. Meeker, Kelly K. Ferguson. Relationship between Urinary Phthalate and Bisphenol A Concentrations and Serum Thyroid Measures in U.S. Adults and Adolescents from NHANES 2007-08. Environmental Health Perspectives, 2011
- Turyk M, . Anderson H, Persky V. Relationships of Thyroid Hormones with Polychlorinated Biphenyls, Dioxins, Furans, and DDE in Adults. Environ Health Perspect. August 2007. 115(8): 1197–1203. Published online 2007 May 31.
- Ha NY, Kim DH, Ryu JY. Relationship between triclosan exposure and thyroid hormones: the Second Korean National Environmental Health Survey (2012–2014). Ann Occup Environ Med. 2019; 31: e22. Published online 5, Sep 2019.
- Amira M. Aker, Deborah J. Watkins et al. Phenols and parabens in relation to reproductive and thyroid hormones in pregnant women. Environmental Research, Volume 151, 2016.
- Leung A, Pearce E, Braverman L. Perchlorate, iodine and the thyroid. Best Pract Res Clin Endocrinol Metab. Feb 2010; 24(1): 133–141.
- Jaggy A, Glaus T Jr, Tipold A. Neurologische Ausfallserscheinungen im Zusammenhang mit Hypothyreose beim Hund: Literaturübersicht und Fallbeschreibungen [Neurologic symptoms in relation to hypothyroidism in the dog: review of the literature and case reports]. Schweiz Arch Tierheilkd. 1994;136(8):257-64. German. PMID: 8091179.
- Sharma AK, Basu I, Singh S. Efficacy Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial. J Altern Complement Med. March 2018. Epub 22, Aug 2017. 24(3):243-248.
- Laurberg P. Forskolin stimulation of thyroid secretion of T4 and T3. EBS Lett. 1984 21, May 1984. 170(2):273-6.
- Panossian A, Wikman G. Pharmacology of Schisandra chinensis Bail.: an overview of Russian research and uses in medicine. J Ethnopharmacol. 23 July 2008.
- Catherine Ulbricht, Ethan Baschet al. Alternative and Complementary Therapies. Seaweed, Kelp, Bladderwrack. Aug 2013.217-230.
- Clark C, Bassett B, Burge M. Effects of kelp supplementation on thyroid function in euthyroid subjects. Endocr Pract. Sep-Oct 2003. 9(5):363-9.
- Malikov D (2017) Traditional Chinese Medicine Approach to Hypothyroidism. Int J Complement Alt Med 5(1): 00142.