From Cat

Dexamethasone is a potent anti-inflammatory and immunosuppressant corticosteroid used extensively in cats.

Dexamethasone is a synthetic analogue of prednisolone, having similar but more potent anti-inflammatory therapeutic action and diversified hormonal and metabolic effects. The dosage of Dexamethasone required is markedly lower than that of prednisone and prednisolone. Dexamethasone has approximately 20 times the anti-inflammatory activity of prednisolone and 70 to 80 times that of hydrocortisone. Dexamethasone does not cause significant sodium or water retention in cats.

Dexamethasone is used as a short-term drug for acute allergies in cats followed by oral supplementation with prednisolone.