Hypothyroidism in dogs: signs and diagnosis

Signs of hypothyroidism can also occur with other conditions. Diagnosis requires a clinical history, examination and coordinated interpretation of test results.

Possible but non-specific signs

Changes in weight, activity, skin or coat may guide the investigation, but they do not confirm hypothyroidism on their own. Age, medicines and concurrent diseases can alter the results.

It is therefore important to avoid self-diagnosis based on a single symptom.

The diagnostic process

The veterinarian selects and interprets tests in their clinical context. A single value is not always sufficient, and other causes may need to be ruled out.

Additional tests are chosen for the individual case rather than applied automatically to every dog.

Treatment and monitoring

Once the diagnosis is confirmed, the medicine and monitoring plan are prescribed individually. Do not change the product, timing or management without consulting your veterinarian.

Sources and document updates

This information is general and does not replace diagnosis, prescription or instructions from a veterinarian. For a medicine, the summary of product characteristics or package leaflet for the specific presentation is authoritative.

• AAHA — 2023 selected endocrinopathies guidelines (accessed 24/07/2026)
• Union Product Database — Veterinary medicines authorised in the European Union (accessed 24/07/2026)

Editorial transparency: sources are provided to allow the documents to be checked. Professional review is only declared after genuine approval by a qualified, identifiable person.