Hyperthyroidism and Your Dog's Diet
Affecting up to 1% of all dogs, hyperthyroidism is a common endocrine disorder in canines. It occurs when the thyroid gland produces an excess of the hormone thyroxine. Although hyperthyroidism can occur in dogs of any age, it is most commonly seen in middle-aged to senior dogs. Fortunately, with early diagnosis and treatment, most dogs with hyperthyroidism can lead happy, healthy lives.
HWhen your dog starts slowing down, gaining weight, or losing hair, you might think it’s just aging. But often, there’s a deeper reason—especially in certain breeds. Hypothyroidism is one of the most common endocrine disorders in dogs, and when left unchecked, it can affect everything from mood and metabolism to skin and immune health.
Let’s talk about what’s really going on… and how you can support your dog naturally.
What Is Hypothyroidism in Dogs?
Hypothyroidism occurs when the thyroid gland doesn’t produce enough hormones—specifically thyroxine (T4) and triiodothyronine (T3). These hormones play a critical role in regulating metabolism, energy, body temperature, and more. When hormone production slows, the whole system lags behind.
Why It Happens (And Why It Matters)
The most common cause is autoimmune thyroiditis, where the immune system attacks the thyroid itself. But that’s not the only trigger. Other contributors include:
Genetic predisposition (especially in Golden Retrievers, Labradors, Dobermans, Boxers, and Cocker Spaniels)
Highly processed diets that lack essential nutrients
Environmental toxins, including fluoride, pesticides, and heavy metals
Chronic gut issues or inflammation
Over-vaccination or poor detoxification ability
When the thyroid is underperforming, your dog may feel tired, moody, or just “off”—but it often gets missed until symptoms get worse.
Symptoms to Watch For
Some of the signs overlap with other issues, which is why many pet parents don’t catch it right away:
Weight gain (without an increase in food)
Low energy, reluctance to exercise, or general sluggishness
Dry, flaky skin or thinning coat
Frequent ear or skin infections
Cold intolerance (seeking warmth, shivering)
Behavioral changes (more nervous, withdrawn, or even aggressive)
Slow heart rate
Thickened, darkened skin—especially on the belly or armpits
See your veterinarian for an official diagnosis. Then you and I can collaborate on a wellness strategy to support your dog.
How Vets Diagnose It
A standard thyroid panel typically includes:
Total T4
Free T4
Total T3
TSH (thyroid-stimulating hormone)
TgAA (thyroglobulin autoantibodies, if autoimmune disease is suspected)
It’s important to understand: a low T4 alone isn’t diagnostic. Illness, stress, medications, and poor nutrition can all suppress T4 levels temporarily. A full panel gives the clearest picture.
Conventional Treatment Options
Most veterinarians prescribe levothyroxine, a synthetic version of the missing hormone. This can help regulate thyroid levels, but it doesn’t address why the thyroid is off balance in the first place.
Some dogs do well on the medication. Others may develop:
Excessive thirst or urination
Restlessness or anxiety
Digestive changes
A dependency that masks deeper health issues
That’s where natural support can make a real difference.
Natural Ways to Support Thyroid Function in Dogs
Holistic support focuses on restoring balance—not just replacing hormones. Even if your dog is already on meds, these strategies can complement conventional care.
Species-Appropriate Nutrition
A fresh food diet supports endocrine function more effectively than kibble, which is often high in carbs and lacking in key nutrients. Focus on:
High-quality proteins
Healthy fats
Low-starch veggies
Thyroid-Friendly Nutrients
Certain nutrients are essential for healthy thyroid function:
Iodine – found in small amounts in certain fish and sea vegetables (too much can be harmful, so balance is key)
Selenium – supports hormone conversion
Zinc – important for hormone production and immune health
Reduce Inflammation
Chronic inflammation can fuel thyroid problems. Consider:
Functional mushrooms (like reishi or turkey tail)
Omega-3 fatty acids from fish or algae
Anti-inflammatory herbs and whole foods
Detox Gently
Toxins burden the thyroid. Common culprits include:
Fluoride in tap water
Household cleaners and lawn chemicals
Heavy metals in food and environment
Regular, safe detox support helps your dog eliminate stored toxins without stressing the body.
Essential Oils and Herbs
Natural remedies can support both the thyroid and immune system:
Adaptogenic herbs to balance endocrine responses
Essential oils that encourage healthy metabolism and lymphatic drainage
Nervine herbs to calm the system if anxiety is present
Want help choosing which ones are right for your dog? That’s where I come in.
Top 5 Things to Do if Your Dog Has (or May Have) Hypothyroidism
Switch to a fresh, species-appropriate diet—limit starchy carbs
Avoid fluoride—use filtered water and fluoride-free toothpaste
Include iodine-rich, selenium-rich, and zinc-rich whole foods
Support liver detox with food-based and herbal options
Watch for behavior or skin changes—and track them!
Need Help With the Details?
Let’s get you on the schedule!