Hypothyroidism in Dogs

Low Risk Endocrine Hereditary

Hypothyroidism is a low-severity endocrine condition that can affect dogs of all ages and breeds. Hypothyroidism is the most common endocrine disorder in dogs, caused by reduced thyroid hormone production — most often from immune-mediated thyroiditis or idiopathic follicular atrophy. It affects metabolism, skin, and coat quality. It is documented across 6 breeds, though prevalence and severity can differ significantly between them. It typically becomes apparent at 4-10 years. Early signs to watch for include weight gain without diet change, lethargy, cold intolerance, and bilateral symmetrical hair loss. When treatment is required, costs are estimated at £300-£800/year depending on severity, location, and the specific intervention needed. Hypothyroidism has a hereditary component, so health-screening certificates from the breeder are strongly recommended for predisposed breeds. This page covers symptoms, treatment options, and preventive steps — along with breed-specific information where available.

Signs & Symptoms

The following symptoms are commonly associated with Hypothyroidism in dogs. If your dog displays several of these signs, consult your vet promptly — early diagnosis typically leads to better outcomes.

Weight gain without diet change
Lethargy
Cold intolerance
Bilateral symmetrical hair loss
Thickened skin
Ear infections

Treatment Overview

Daily oral thyroxine (levothyroxine) supplementation is highly effective and required for life. Dosing is adjusted based on thyroid level monitoring every 6-12 months.

Typical onset: 4-10 years

Prevention & Screening

While not all cases of Hypothyroidism can be prevented, the following steps reduce risk or enable earlier intervention:

No proven prevention
Regular blood screening in at-risk breeds from age 4

Estimated Treatment Cost

Treatment for Hypothyroidism is estimated at £300-£800/year, depending on severity, the specific intervention required, and your location. Costs may be higher for surgical procedures or ongoing management. Comprehensive pet insurance covering hereditary conditions is strongly recommended.

Breeds Affected by Hypothyroidism

The following 53 breeds are documented as being susceptible to Hypothyroidism. Click any breed to view breed-specific information about this condition, including prevalence and recommended screening.

Looking for more information? Browse all dog health conditions or explore the health guides for in-depth breed care advice.