Recombinant human thyrotropin stimulation test in 114 dogs with suspected hypothyroidism: a cross‐sectional study

Objective To evaluate the performance and define cut‐offs for the interpretation of a thyroid‐stimulating hormone (TSH) stimulation test with a recombinant human TSH dose of 75 μg/dog administered intravenously in dogs with suspected hypothyroidism. Materials and Methods Cross‐sectional study. Medical records of dogs presented for suspected hypothyroidism were retrospectively reviewed. Animals were included if a TSH stimulation test with a recombinant human TSH dose of 75 μg/dog was performed and follow‐up was available. Dogs with a post‐TSH serum total thyroxine (T4) level of ≥2.2 μg/dL were considered euthyroid. Dogs with a post‐TSH T4 level of 1.7 μg/dL had a negative predictive value of 100%. Post‐TSH T4 levels of 1.7 μg/dL is suggestive of normal thyroid function.