Species: Canine. feline, equine

Specimen: Serum

Container: Plain (red top) or gel (serum separator) tube

Collection protocol: Standard venepuncture

Special handling/shipping requirements:

Send samples to the laboratory within 12-24 hours of collection.

General information about the disease:

This is a measure of all T4 in the circulation and includes protein-bound and Free-T4 (FT4). Total-T4 (TT4) is generally recognised as the standard screening test used for determining baseline thyroid status in dogs and cats.  As with all endocrine disease, diagnosis is can be complicated by concurrent disease and use of medications, including certain antibiotics, corticosteroids and anticonvulsants. As TT4 predominantly measures protein-bound thyroid hormone, it may be affected by conditions that impact on the patient’s serum proteins. Thus, interpretation of results should always take clinical history into account and may be aided by combining TT4 with FT4 and canine TSH as appropriate. Awanui Veterinary Pathology offers an automated enzyme immunoassay for testing TT4.

See “Diagnosis and monitoring of hypothyroidism” and “Diagnosis and monitoring of hyperthyroidism” for more information.

General information about when this test is indicated:

Screening for the presence of hyperthyroidism or hypothyroidism, and monitoring the treatment of these diseases.

Comparison with other related tests:

See “Diagnosis and monitoring of hypothyroidism” and “Diagnosis and monitoring of hyperthyroidism”