Hypercortisolism in a Cat

Hypercortisolism in the cat can be iatrogenic, pituitary-induced, or due to an adrenal tumor. Iatrogenic causes are allegedly rare in cats because of their apparent innate resistance to catabolic effects of glucocorticoid drugs; however, this was not the case for a 7-year-old, spayed female domestic longhair cat that received an injection of triamcinolone acetonide for suspected skin allergies.

The cat showed various adverse effects from the drug, including dry and very friable skin; unique pathologic folding of the ear tips; short hair coat; and several abnormal serum biochemistry measurements, including glucose (165 mg/dL), cholesterol (606 mg/dL), alkaline phosphatase (548 U/L), aspartate transaminase (598 U/L), and alanine transaminase (2551 U/L). The cat was also lethargic, polydipsic, and polyuric.

Fine-needle aspiration of the liver showed hepatocyte vacuolization. A periodic acid-Schiff stain was positive, identifying the vacuoles as glycogen. Results of both the resting and post-ACTH stimulation tests were 0.2 µg/dL, which is compatible with iatrogenic hypercortisolism. The physical and serum biochemical abnormalities resolved over the next 8 weeks.

HYPERCORTISOLISM IN A CAT • Michael Schaer

Reference1. Hyperadrenocorticism in cats (Cushing's syndrome). Feldman EC, Nelson RW (eds). Canine and Feline Endocrinology and Reproduction,3rd ed-St. Louis: Elsevier Saunders, 2004, pp 359-392.