Maybe your dog has allergies, or perhaps he's been diagnosed with Addison's disease -- whatever the reason, the vet has prescribed prednisone as part of his therapy. As a corticosteroid, it works to keep his body from producing substances that prompt immune and inflammatory responses. It comes with a variety of side effects, ranging from mild reactions, such as panting, to more serious consequences, such as diabetes.
Minor to Serious Side Effects
Prednisone has a variety of uses, helpful as an anti-inflammatory when your dog's suffering joint pain, useful for improving circulation in a shock situation and beneficial in treating mast cell tumors as part of a chemotherapy regimen. However, there are short-term and long-term consequences when using the drug. Prednisone affects a dog's kidneys, resulting in his body's conservation of salt, leading to the most common side effect to prednisone: excessive thirst and urination. Other effects of prednisone include lethargy, panting, diarrhea, vomiting, delayed healing, aggression, changes in behavior, decreased growth rate in young dogs and ulceration in the digestive tract. Long term use of the drug can result in diabetes and Cushing's disease. Due to its effect on blood sugar, diabetic dogs should avoid taking prednisone; pregnant dogs shouldn't take it since it can cause a dog to abort her puppies. It may react with nonsteroidal anti-inflammatory drugs, some antibiotics, antacids, anticoagulants and other steroids, so be sure to keep your vet up to speed on any medication your dog is taking.