Hyperthyroidism Diagnosis

If your cat exhibits some symptoms of hyperthyroidism, consult your vet for diagnosis.


The Process

Diagnosing feline hyperthyroidism begins with a physical examination by your veterinarian.  The process will take into account:

  • Medical History
  • Symptoms, such as weight loss, increased appetite, and others
  • Blood tests to pinpoint the issue and rule out any preexisting conditions
  • Technetium scan to verify the diagnosis, and to precisely pinpoint the abnormal tissue
  • Advanced testing on the heart and other organs to analyze how much damage has already been sustained

Diagnostic Testing

A physical examination is performed by your vet.  In most cases, a tumors can be felt on the thyroid glands.

A blood test is taken to check T3 and T4 levels.  Over 90% of cats with hyperthyroidism show elevated hormone levels. Normal T4 levels in cats range from 12.87 nmol/L – 38.61 nmol/L.

A technetium scan can be done at specialized veterinary practices. A contrast agent is injected allowing the functioning part of thyroid glands to easily be seen.

If results are inconclusive, advanced imaging can be used.  An example is thyroid scintigraphy, which provides a visual look at function and structure of the thyroid glands.