Prednisone, a common glucocorticoid, treats many conditions in both humans and pets, including dogs. It is a fast-acting medication with anti-inflammatory and immunosuppressant properties. Prednisone can be an effective treatment strategy for many pups suffering from a wide range of health issues. However, this popular corticosteroid has numerous possible side effects, risk factors, and potentially dangerous interactions.
Table of Contents
- What is prednisone?
- What is prednisone used to treat?
- Addison’s disease
- Immune suppression
- Anti-inflammatory
- Canine cancer
- How is prednisone administered?
- Potential side effects
- Risk factors
- Not for all dogs
- Proceed with caution
- Interactions with prednisone
What is prednisone?
If your canine companion has ever been prescribed prednisone, you may recognize it by common brand names Prednis-Tab®, Deltasone®, Rayos®, or Pediapred®. You may have also heard prednisone referred to in the same context or interchangeably with prednisolone. According to veterinary experts at VCA Animal Hospitals, prednisone for dogs quickly converts into prednisolone in the liver, so the two are often considered bioequivalent.
Prednisone and prednisolone can generally be used interchangeably in dogs, but if your pup’s liver function is compromised, a veterinarian may prescribe the already converted prednisolone. Additionally, the Veterinary Information Network notes that cats and horses seem to have less efficient activation mechanisms for prednisone and may have more success with prednisolone.
As a glucocorticoid, prednisone falls within the corticosteroid class of medications. Corticosteroids mimic cortisol, a hormone naturally produced in a dog’s adrenal glands that manages inflammation and general homeostasis. Corticosteroids deliver greater concentrations of synthetic hormones than the adrenal glands can produce alone when used to treat many problems, but can be used as replacement to some extent when adrenal glands are not working efficiently.
Classified as a glucocorticoid, the Merck Veterinary Manual notes that prednisone suppresses virtually every component of the inflammatory process, making it “by far the most efficacious” anti-inflammatory drug. At higher doses, prednisone is also immunosuppressive.
What is prednisone used to treat?
Prednisone, notes VCA Animal Hospitals, has several broad uses as a form of replacement therapy for Addison’s disease (adrenal dysfunction), an anti-inflammatory, an immune suppressant, and an antineoplastic for addressing certain cases of cancer in canines. Many of these uses are “off label.” This means that the drug is not approved for that purpose, but healthcare providers often have success using it.
Addison’s disease
Prednisone mimics cortisol, making it an effective tool for addressing hypoadrenocorticism, or Addison’s disease. This disease is characterized by a lack of hormone production by the adrenal glands. Prednisone can be used as replacement therapy when a pup is not producing adequate glucocorticoid hormones on their own. According to VCA, the clinical signs of Addison’s disease are fairly non-specific. These include vomiting, lethargy, electrolyte abnormalities and diarrhea.
Immune suppression
The immunosuppressive properties of prednisone for dogs help treat autoimmune disorders. These are conditions in which the immune system is destructively hyperactive.
Anti-inflammatory
Prednisone’s anti-inflammatory properties can address various inflammatory conditions, including inflammatory bowel disease. The medication is also often prescribed for inflammation that results in joint pain and irritated and itchy skin.
Central nervous system disorders from trauma or disk extrusion are often treated with prednisone. In these cases, the drug is likely to be able to address swelling in the brain or spinal cord.
Canine cancer
Veterinarian Johnny Hoskins notes in DVM360 that prednisone can be used as a chemo-therapy drug for some forms of canine cancer, including lymphoma, leukemia, and mast cell tumors. High doses of prednisone can potentially kill cancer cells, and for dogs with lymphoma, Dr. Hoskins says that approximately half will experience either partial or complete remission for a short period of time.
Prednisone can dramatically improve the clinical symptoms of brain tumors, and can potentially reduce congestion, coughing, and labored breathing associated with nasal tumors and pulmonary metastasis. Pups diagnosed with cancer are likely to experience a lower quality of life with reduced appetite and energy levels. Prednisone is often prescribed to address these cancer-related issues, as well.
How is prednisone administered?
Prednisone is fast-acting, usually taking effect within one to two hours depending on the dose, dog, and symptoms. The medication is typically delivered by mouth in the form of a tablet or liquid solution. VCA Animal Hospitals recommends that prednisone should be taken with food to aid in absorption. It is also possible for prednisone to be administered as an injection in hospital settings.
Potential side effects
It’s important to keep in mind that all dogs react differently to medications. The most common side effects associated with prednisone include increased drinking, urination, and appetite, and high doses of the drug causes mild salt retention. This can be problematic for dogs with congestive heart failure.
At higher doses and for cases of long-term use, some possible side effects of prednisone can include vomiting, diarrhea, panting, and even some mild behavior changes that can make some dogs more aggressive.
Serious side effects can include gastrointestinal ulceration, which may be characterized by a lack of appetite, black or bloody stools, bloody vomit, or high fever. Dogs experiencing negative reactions to prednisone may also exhibit coat changes, distended abdomen, weight gain, muscle atrophy and weakness, elevations in liver and lipid levels, and even can contribute to insulin resistance (diabetes). The Merck Veterinary Manual warns that because the pharmacologic and physiologic effects of prednisone are so broad, the potential for adverse effects is considerable.
Risk factors
There are several serious, potentially fatal risk factors associated with the use of prednisone in dogs. It’s important to closely follow the guidance of a veterinarian when giving your pup this medication.
Not for all dogs
Dogs can be allergic to prednisone (though very rare), so it should not be given to these pets if a known allergy exists. Experts at VCA Animal Hospitals also warn that prednisone should not be used on animals with systemic fungal infections, viral infections, diabetes, ulcers, tuberculosis, heart disease or Cushing’s disease. As previously mentioned, only pets with proper functioning livers should take unconverted prednisone as opposed to prednisolone.
Proceed with caution
VCA also recommends using caution when administering prednisone to pups with heart of vascular disease, osteoporosis, cataracts, high blood pressure, or kidney disease. It’s also possible for glucocorticoid hormones to stunt the growth of young pets and induce labor and or cause abortion in pregnant dogs.
It’s crucial that prednisone use is not stopped abruptly. Instead, a dog should be weaned off the medication slowly to avoid complications. When a dog is on prednisone, its body perceives these synthetic hormones as an indication that the adrenal glands can stop producing cortisol of its own. Eventually, the glands will atrophy. When prednisone is suddenly discontinued, the dog’s body will not likely be able to respond to stress and a blood sugar crisis can result.
Interactions with prednisone
According to VCA Animal Hospitals, the following medications may either disrupt or be disrupted by the use of prednisone:
- Amphotericin B
- Anticholinesterases
- Aspirin
- Barbiturates
- Bupropion
- Cholestyramine
- Cyclophosphamide
- Cyclosporine
- Digoxin
- Potassium-depleting diuretics
- Phedrine
- Estrogens
- Fluroquinolones
- Insulin
- Ketoconazole
- Macrolide antibiotics
- Mitotane
- Mycophenolate
- Phenobarbital
- Rifampin
- Vaccines
- Warfarin
Mar Vista Animal Medical Center warns that glucocorticoid hormones should not be used in combination with non-steroidal anti-inflammatory drugs (NSAIDs). This combination could lead to bleeding and or ulceration in the stomach or intestine. It could also cause a dog to have liver compromise.
Glucocorticoids, including prednisone, may also interfere with laboratory skin testing for allergies, as well as testing of thyroid function, cholesterol, urine glucose, and potassium. The Merck Veterinary Manual suggests that dogs should be off prednisone for at least one month prior to having any of these tests conducted. Many veterinarians will still have blood testing performed while your dog is on prednisone and understand the potential influences of prednisone when interpreting blood results.
Any health or medical information in ElleVet blogs is from a variety of public and reputable sources. This information is intended as an education resource only and is not a substitute for expert professional care.
