Side effects are usually dose dependent. If side effects occur, contact your veterinarian, who may decrease the dosage, frequency, or type of corticosteroid.
The most common side effects are increased appetite, drinking, and urination. Your pet may have more "accidents" and need to go outside or use the litter box more often. Less common side effects include weight gain, panting, diarrhea, vomiting, and behavior changes.
Side effects of daily long-term use include muscle loss, weakness, and the development of diabetes or hyperadrenocorticism (Cushing's disease). The typical signs of these diseases are increased thirst, urination, and appetite. Animals with Cushing's disease may also develop thin skin, a poor hair coat, and a "pot-belly." Side effects may also include activation or worsening of hypothyroidism or pancreatitis.
Immune system suppression may occur at high doses, making a pet more susceptible to infection. Contact your veterinarian if your pet has a fever (over 103° F), painful urination (a sign of urinary tract infection), tiredness, sneezing, coughing, or runny eyes.