Prednisone and Prednisolone

Stephanie Howe, DVM
By Stephanie Howe, DVM on Jul. 7, 2022

In This Article


PetMD’s medications content was written and reviewed by veterinary professionals to answer your most common questions about how medications function, their side effects, and what species they are prescribed for. This content shouldn’t take the place of advice by your vet

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What is Prednisone and Prednisolone?

Prednisone and prednisolone are types of steroid medications called corticosteroids. They are also further classified as glucocorticoids, which are steroids that occur naturally in the body.

Either prednisone or prednisolone can be used in dogs because a healthy canine liver can convert prednisone to its active metabolite, prednisolone. Cats, however, cannot absorb and convert prednisone as well as other animals, so prednisolone is preferred. Veterinarians often prescribe prednisolone to cats and to dogs with liver failure.

Glucocorticoids are medications that have many functions depending on how they are administered. They can act as anti-inflammatories, treat immune mediated diseases, severe allergic reactions, deficiencies of natural body steroids (Addison's disease).

In certain circumstances, your vet may recommend a compounded formulation of prednisone or prednisolone. Compounded medications are prescribed if there’s a specific reason your pet’s health can’t be managed by an FDA-approved drug. Compounded medications are not FDA-approved. They are created by either a veterinarian or a licensed pharmacist on an individual basis to best suit a patient’s particular needs. You can learn more about compounded medications here.

How Prednisone and Prednisolone Work

Prednisone and prednisolone are steroids that are also hormones. They have effects on almost every type of cell in an animal’s body and can function in a variety of ways. The action of either medication also depends on the amount given—your veterinarian will prescribe the dose that is appropriate for your pet’s medical condition.

At lower doses, prednisone or prednisolone can reduce inflammation and have broad anti-inflammatory effects. At higher doses, they can suppress the immune system response, which may be helpful in treating certain forms of cancer.

Prednisone and Prednisolone Directions

Follow the directions on the drug label and as provided by your veterinarian. Check the label closely, as the recommended dosage often changes over the course of treatment.

Treatment with prednisone or prednisolone for more than one to two weeks may interfere with their bodies’ production of their own steroids. To account for this, veterinarians usually recommend that the dose be slowly decreased over time until your pet is no longer on this medication. Make sure to follow all tapering dosing directions closely.

Do not stop the medication before the end of treatment without first discussing it with your veterinarian. Abruptly stopping long-term treatment without tapering the dose can cause serious side effects.

Missed a Dose?

If you forget to give a dose of prednisone or prednisolone, give it when you remember. However, if it is almost time for your next dose, skip the missed dose and resume your normal dosing schedule. Do not give extra or double doses.

Prednisone and Prednisolone Possible Side Effects

Prednisone or prednisolone may cause side effects, which are dependent on the dose the pet is receiving and how long they have been on the medication.

The most common side effects include the following:

  • Increased thirst

  • Increased urination (increased amount and frequency, may cause pets to have accidents inside the house)

  • Increased appetite

  • Panting

  • Vomiting/Diarrhea

Additional side effects can occur, especially when the medication is given long-term or at higher doses. These additional side effects may include:

  • Weight gain

  • Poor haircoat or hair loss

  • Muscle wasting (atrophy)

  • Decreased energy level or weakness

  • Stomach or intestinal ulcers (sores) - may present as bright blood in vomit

  • Bleeding into the digestive tract – may present as black and tar-like stools

  • Triggering or worsening of diabetes mellitus

  • Increased risk for infections

  • Pot-belly appearance (distended abdomen)

  • Behavior changes (aggression, depression, lethargy)

Prednisone or prednisolone can suppress the immune system response at higher doses. This may cause pets to be more susceptible to infection. Abruptly stopping prednisone or prednisolone can cause serious side effects. Contact your veterinarian before prematurely discontinuing prednisone or prednisolone. Your veterinarian can recommend a gradual reduction in dosing to reduce the likelihood of serious side effects.

Human Side Effects

While this medication is used in humans, it may be given differently and have different side effects. If you accidentally ingest this medication, call your physician or local poison control center.


Your veterinarian is likely to recommend routine testing while your pet is on this medication. Testing may vary depending on your pets' individual needs, any other medications they may be on and/or the issue that initially caused your pet to be placed on this medication. Most common recommendations for monitoring on this medication is blood work, encompassing a complete blood cell count and chemistry panel, urinalysis and blood pressure monitoring.

Call Your Vet If

  • Severe side effects are seen (see above) or if you see or suspect an overdose

  • Call your vet or pharmacist if you have additional questions or concerns about the use of prednisone or prednisolone

Prednisone and Prednisolone Overdose Information

Overdoses of prednisone or prednisolone can cause digestive upset, especially in dogs. Signs may include vomiting, diarrhea, decreased appetite, blood in the vomit or black, tar-like stools. If you suspect an overdose, immediately contact your veterinarian or an animal poison control center. Consultation fees often apply.

Pet Poison Helpline (855) 764-7661

ASPCA Animal Poison Control (888) 426-4435

Prednisone and Prednisolone Storage

Prednisone should be stored at controlled temperatures between 68-77°F and brief exposure to temperatures 59°-86°F are acceptable, but always confirm storage requirements by reviewing the label. Keep the container tightly closed in order to protect from moisture and light.

Compounded medications should be stored according to the compounding pharmacy’s label.

Keep out of reach of children and pets.

Prednisone and Prednisolone FAQs

Is prednisone a diuretic for dogs?

Diuretics are medications that stimulate the kidneys to release water and electrolytes from the body. This reduces the amount of fluid in the blood vessels and ultimately the body. Prednisone is not used as a diuretic in dogs, but it can affect the balance of water and electrolytes in the body. Both diuretics and prednisone can cause an increase in thirst and urination in dogs.

Is prednisone a painkiller for dogs?

The short answer is no. The long answer is that prednisone can be an anti-inflammatory drug. For dogs that have pain caused by inflammation, prednisone can decrease the inflammation and relieve the pain associated with the inflammation. Depending on the cause of your dog’s pain, safer and more effective pain medications may be a better option.

How long does it take for prednisone to work in dogs?

Prednisone will start working within one to two hours of treatment. Your dog’s symptoms will likely start to improve shortly after that. Talk to your veterinarian if you do not see signs of improvement within a few days of starting treatment.


Does prednisolone make cats sleepy?

Cats tend to tolerate prednisolone well, however, a reduced energy level may sometimes be observed. If your cat is very sleepy, this is unusual, and your veterinarian should be contacted.

No vet writer or qualified reviewer has received any compensation from the manufacturer of the medication as part of creating this article. All content contained in this article is sourced from public sources or the manufacturer.


Featured Image: iStock/Chalabala

Stephanie Howe, DVM


Stephanie Howe, DVM


Dr. Stephanie Howe graduated from the University of Florida College of Veterinary Medicine in 2011, after receiving a Bachelor of Science...

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