Your veterinarian might prescribe prednisone for any one of a wide range of ailments, from cancer to allergic reactions. Prednisone, a glucocorticoid and corticosteroid medication, is very effective for controlling inflammation and pain. Like any drug, prednisone has side effects. Most are relatively mild, but you should be aware of them, especially if your dog is taking prednisone over a long period of time.
Prednisone makes dogs very thirsty, so you'll likely notice your dog drinking a lot more. Naturally, your pet will need to urinate more frequently. VetInfo's Dr. Mike Richards notes that increased thirst and urination may be more noticeable after a prednisone injection as compared to oral prednisone, and that this side effect should last for only a few days.
Prednisone increases appetite; it is sometimes given to canine cancer patients to help encourage them to eat and prevent cachexia, or cancer wasting, according to the University of Georgia College of Veterinary Medicine's oncology department. Generally, though, you don't want your dog to gain weight. Give it low-calorie snacks instead of increasing its food rations. Discuss feeding options with your veterinarian if your dog is going to stay on prednisone for a long time, so it can remain at a healthy weight.
Prednisone suppresses immune response--this is one reason it's prescribed for severe allergies. Your dog may be more susceptible to bacterial infections, cautions Dr. Richards. For long-term prednisone use, make sure your dog is on the lowest effective dose, or talk to your veterinarian about giving prednisone every other day instead of daily.
Hair Loss and Skin Problems
If your dog is on only a short course of prednisone or receives a single injection, it shouldn't affect its skin or coat. However, Dr. Richards states that dogs on long-term prednisone therapy often start losing fur and having skin problems. Prednisone makes the skin thinner and prone to sores called calcinosis cutis.
A dog on prednisone becomes less tolerant of higher temperatures and may pant a lot. Make sure your dog has a cool place to rest and avoid strenuous activities or play when it's hot.
Side Effects with Other Medications
Many dogs are prescribed prednisone to ease the inflammation and pain associated with arthritis. Prednisone in conjunction with aspirin or non-steroidal anti-inflammatory arthritis drugs such as carprofen or etodolac can cause gastrointestinal problems such as diarrhea and stomach ulcers, warns the University of Georgia.