Thyroid Stimulating Hormone (Thyrotropin Alfa, TSH)

Thyroid-stimulating hormone
(Thyrotropin alfa, TSH) In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• Binds to specific receptors on thyroid follicular cell membranes.
• Stimulates proteolytic degradation of thyroglobulin.
• Promotes the release of thyroxine (T4) and smaller amounts of tri-iodothyronine (T3).

Uses of Thyroid stimulating hormone
(Thyrotropin alfa, TSH)

• Stimulation of thyroid hormone production in the diagnosis of canine hypothyroidism (not suitable for evaluation of thyroid function in patients receiving levothyroxine).
• The diagnostic value in cats has not been fully assessed.

Dose of Thyroid-stimulating hormone
(Thyrotropin alfa, TSH) in Dogs and Cats

Dogs:

• TSH stimulation test: 50–150 μg (micrograms)/dog.
• Higher doses offer increased discriminatory power in dogs with comorbidities or those receiving thyroid-suppressing drugs.

Cats:

• TSH stimulation test: 25 μg (micrograms)/cat.

Side Effects of Thyroid stimulating hormone
(Thyrotropin alfa, TSH) in Dogs and Cats

• Chemical grade TSH may be associated with anaphylactic responses; do not use.

Contraindications of Thyroid stimulating hormone
(Thyrotropin alfa, TSH) in Dogs and Cats

• Repeated administration is not advisable.

Some Notes:

• Anabolic or androgenic steroids, carbimazole, barbiturates, corticosteroids, diazepam, heparin, mitotane (o, p’-DDD), phenylbutazone, phenytoin and salicylates may all decrease serum T4 levels.
• Fluorouracil, insulin, oestrogens, propranolol and prostaglandins may cause T4 levels to be increased.
• All these drugs will make the TSH stimulation test hard to interpret.