Prednisone for dogs: Dosage, side effects, and safety

Prednisone is a synthetic corticosteroid used widely to treat numerous problems in dogs. Corticosteroids are hormones created within the pituitary gland that regulate the functions of cells and hormones throughout the body. They affect practically every cell and system in the dog’s body. Among veterinarians, prednisone is commonly used as an anti-inflammatory drug to reduce inflammation, control autoimmune disease, treat certain types of cancers, and as hormone replacement therapy in dogs with hormone (endocrine) disorders. Prednisone is the inactive form of prednisolone. It is converted to prednisolone in the body after a dose is given. Veterinarians often use the two drugs interchangeably at equivalent doses.

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What is prednisone used for in dogs?

Prednisone has a wide range of effects on the body, so veterinarians prescribe prednisone for a wide variety of uses:

• To reduce inflammation due to conditions such as arthritis, allergies, or injuries
• To suppress the immune system in dogs with autoimmune diseases such as lupus
• To treat certain types of cancers such as lymphoma, mast cell tumors, or multiple myeloma, as well as treat conditions associated with cancer or cancer treatment
• To replace glucocorticoid hormones in dogs that are deficient in those hormones

Inflammation

Most pet owners most likely will be prescribed prednisone when their dog is suffering from joint pain, allergic reactions, skin reactions, or injuries. Low doses of prednisone significantly reduce swelling and any associated symptoms like pain or stiffness. Arthritis, allergic reactions, asthma, itching, injuries, and some tumors are all conditions that can benefit from the anti-inflammatory effects of short-term prednisone or prednisolone therapy.

Inflammatory conditions

Like humans, some dogs have autoimmune conditions such as lupus, rheumatoid arthritis, inflammatory bowel disease, and autoimmune hemolytic anemia. In these cases, the immune system overreacts and mistakenly attacks and damages healthy tissues. At high doses, prednisone, prednisolone, or other corticosteroids block the immune system to control flare-ups of these conditions. 

Cancer

Corticosteroids such as prednisone or prednisolone can stop the growth of certain types of cancers that involve lymph cells, such as lymphomas, leukemia, and multiple myeloma. Of the lymphatic cancers, lymphoma is common, representing about 15% to 20% of cancers diagnosed in dogs every year. Lymphatic cancer cells have corticosteroid receptors that induce those cells to die. Prednisone is usually used as an add-on treatment to chemotherapy drugs or as a palliative treatment for advanced cancers. For other cancers, low doses of prednisone or prednisolone may be used to treat other conditions associated with cancer to help the dog feel better.

Hormone replacement

When dogs don’t produce enough corticosteroids naturally, veterinarians call this condition adrenal insufficiency or Addison’s disease. It’s relatively rare, affecting less than 0.5% of dogs. It’s not easy for an owner to spot because the symptoms are vague, but signs include lack of appetite, vomiting, diarrhea, and lethargy. Dogs with adrenal insufficiency will be given low doses of a glucocorticoid like prednisone and a mineralocorticoid as hormone replacements, About 50% of dogs with low cortisol levels will be put on daily prednisone.

Is prednisone safe for dogs?

Prednisone is safe for dogs provided it’s given under the direction of a veterinarian. However, there are potential problems a dog may experience. 

According to Plumb’s Medication Guides, prednisone is never safe to give to dogs:

• Allergic to the drug
• With a fungal infection inside the body called a systemic fungal infection
• With gastrointestinal ulcers
• With excess cortisol levels (Cushing’s syndrome)

Although not prohibited, prednisone may cause problems in dogs with certain medical conditions, including:

• Bacterial infections
• Diabetes
• Heart failure

Prednisone should be avoided in pregnant dogs since it can cause them to go into labor prematurely and has been linked to birth defects in their puppies. Long-term use of prednisone can stunt the growth of puppies younger than 6 months.

Side effects of prednisone in dogs

The most common side effects of prednisone in dogs include:

• Increased appetite
• Thirstiness
• Frequent urination
• Behavior changes
• Panting

Other potential side effects include:

• Dry or dull-looking coat
• Vomiting
• Diarrhea
• Elevated liver enzymes

Serious side effects include:

• Stomach or intestinal ulcers
• Gastrointestinal bleeding
• Gastrointestinal perforation
• High blood sugar or diabetes
• Infections, particularly urinary tract infections
• Muscle wasting
• Severe changes in behavior, such as aggression

A dog can’t tell its owner about stomach ulcers, infections, high blood sugar, or similar severe adverse reactions. Instead, owners should watch for signs of these effects and call the veterinarian:

• Blood in the stools
• Black and tarry stools
• Bloody vomit
• Loss of appetite
• Weight loss
• Excessive thirst
• Excessive urination
• Lethargy
• Fever
• Pain when urinating
• Urinary accidents

Interactions of prednisone with other pet meds

Steroids affect nearly every system in the body, so several types of drug interactions can cause problems:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) increase the risk of gastrointestinal problems such as ulcers and bleeding. They aren’t prohibited, but veterinarians will try to avoid them.
• Prednisone increases blood sugar, so dogs on insulin may require higher doses of insulin.
• Diuretics increase the risk of low potassium.
• Live vaccines should be avoided because prednisone weakens the immune system.
• Some drugs speed up the body’s metabolism of prednisone, making it less effective.

Prednisone can affect the results of many important tests such as allergy tests, cholesterol tests, blood sugar tests, potassium levels tests, and thyroid hormone tests. 

Prednisone dosage for dogs

For prednisone, the goal in veterinary medicine is to give the dog the lowest possible dose for the shortest period of time. Veterinarians may start at a recommended dosage and decrease or increase the dose as necessary.

• Recommended prednisone dosage in dogs for inflammation: 0.5–1 mg/kg taken as a single or divided dose daily
• Recommended prednisone dosage in dogs for autoimmune disorders: 1.5–4 mg/kg per day
• Recommended prednisone dosage in dogs for cancer (neoplasia): 2 mg/kg daily for three to four weeks before receiving a tapering dose
• Recommended prednisone dosage for adrenal insufficiency: 0.1 mg/kg daily 

Corticosteroids suppress the ability of adrenal glands in the dog to make corticosteroid hormones. If the drug is stopped too suddenly, the dog will experience adrenal insufficiency. It could be life-threatening. When it’s time to stop prednisone, the veterinarian will prescribe a steadily decreasing dose of prednisone.

Can dogs overdose on prednisone?

Dogs can overdose on prednisone. If an owner suspects or knows that a dog has taken too much prednisone, call the veterinarian or an animal poison control center. 

Mostly, however, most overdoses occur because the dose is too high. This is called medication-induced Cushing’s disease. It will take a while for problems to manifest. Look for signs such as:

• Weight gain
• Pot-bellied appearance
• Weakness
• Thin skin
• Thin coat or hair loss
• Excessive urination
• Excessive thirst

Can I give my dog prednisone every day?

Veterinarians will prescribe prednisone daily or every other day. Dogs can take prednisone daily over the long-term, but when therapy lasts for longer than four months, serious problems are possible. 

How to give your dog prednisone

Prednisone is given to dogs by mouth. Because prednisone has such powerful effects on the dog’s body, it’s important to dose the dog carefully. 

• Follow the veterinarian’s dosage instructions carefully.
• Give prednisone tablets or oral solution with food.
• Give it at the same time each day. The veterinarian may suggest dosing dogs in the morning.
• Do not skip doses. 
• If a dose is missed, give it as soon as it’s remembered. If it’s almost time for the next dose, skip the missed dose. Never give the dog extra prednisone or a double dose.
• Do not stop giving the dog prednisone until told to do so by the veterinarian. When it’s time to quit, the dog may need to have a steadily decreasing dose.
• Store prednisone tablets at room temperature.

Prednisone alternatives for dogs

Prednisone and prednisolone are appropriate drugs for many conditions, but they may not be appropriate for your dog. Veterinarians do have alternative treatments for many of the conditions prednisone is used for:

• Other corticosteroids, including topical steroids
• NSAIDs to manage pain or reduce swelling
• Other pain medications
• Antihistamines for allergic reactions or itching
• Chemotherapy for cancer
• Other types of immunosuppressive drugs, such as cyclosporine

Alternative or complementary treatments for some of the conditions treated by prednisone include:

• Omega-3 fatty acid supplements
• Glucosamine-chondroitin for joint pain
• Probiotics for inflammatory bowel disease

Summary

Prednisone and prednisolone are widely used to treat a number of conditions in dogs. Although prednisone can cause serious problems, veterinarians take great care to minimize the risks. Long-term use is problematic, so veterinarians regularly examine the animal and do blood work to make sure there aren’t problems. Prednisone should be safe and effective if pet parents follow the veterinarian’s instructions, watch for side effects, and contact the veterinarian when problems occur.