Thyroid Tumours is a high-severity cancer condition that can affect dogs of all ages and breeds. Canine thyroid tumours are uncommon but often malignant (carcinoma). Moveable non-invasive tumours respond well to surgery; fixed invasive tumours are associated with metastasis. Functional tumours cause hyperthyroidism, unlike the common hypothyroid tendency of inflammatory thyroid disease. It is documented across 3 breeds, though prevalence and severity can differ significantly between them. It typically becomes apparent at 9-11 years. Early signs to watch for include palpable neck mass, difficulty swallowing or breathing, weight loss, and increased activity and appetite (functional tumours). When treatment is required, costs are estimated at £2,000-£8,000 depending on severity, location, and the specific intervention needed. 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 Thyroid Tumours in dogs. If your dog displays several of these signs, consult your vet promptly — early diagnosis typically leads to better outcomes.

• Palpable neck mass
• Difficulty swallowing or breathing
• Weight loss
• Increased activity and appetite (functional tumours)
• Coughing

Treatment Overview

Surgical resection of moveable tumours is curative in many cases. Radioactive iodine (I-131) is effective for functional tumours. Chemotherapy is used for metastatic disease.

Typical onset: 9-11 years

Prevention & Screening

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

• No proven prevention
• Prompt evaluation of neck masses

Breeds Affected by Thyroid Tumours

The following 3 breeds are documented as being susceptible to Thyroid Tumours. Click any breed to view breed-specific information about this condition, including prevalence and recommended screening.

• Golden Retriever (large)
• Beagle (small)
• Boxer (large)