Can Infection Cause Hyperthyroidism in Dogs?

Not usually. An overactive thyroid is rare in dogs. It's most often caused by too high a dose of thyroid medication, by raw-meat diets or treats that contain thyroid tissue, or, occasionally, by a hormone-producing thyroid tumor.

Illness and infection more commonly lower thyroid test results, which is why vets avoid testing during illness.

See hypothyroidism in dogs.

This is general information, not a diagnosis. Please follow your own vet's advice.