Get the facts on prednisone and prednisolone for dogs and cats from petMD. prednisone or prednisolone does not often result in serious side effects in dogs and cats. Cushing's disease; Vomiting; Diarrhea; Ulceration of the digestive tract. This is because this medication can cause stomach upset but also dampen the immune system making dogs more vulnerable to infections. Therefore, we do not . Prednisone is often prescribed to dogs who suffer from arthritis, inflammation Although helpful for your pet, prednisone could cause side effects that . These may include vomiting, diarrhea, muscle weakness, joint pain, and.