Prednisone and prednisolone are corticosteroid medications that are among the most commonly prescribed drugs in veterinary medicine. They are powerful anti-inflammatory and immunosuppressive agents used to treat a wide range of conditions in dogs, from allergies and skin disorders to autoimmune diseases and certain cancers. Prednisone is a prodrug that is converted to its active form, prednisolone, in the liver. Dogs convert prednisone to prednisolone efficiently, so either form is typically effective. However, this is an important species distinction: cats and horses cannot efficiently convert prednisone and should receive prednisolone instead. These medications require a veterinary prescription, careful dosing, and — when used for more than a few days — a gradual tapering schedule when it is time to discontinue.
What Is Prednisone/Prednisolone Used For?
Prednisone and prednisolone are prescribed for a remarkably broad range of conditions in dogs:
- Allergic reactions and allergic dermatitis — reducing itch, swelling, and skin inflammation
- Autoimmune diseases — immune-mediated hemolytic anemia (IMHA), immune-mediated thrombocytopenia (ITP), pemphigus, and other autoimmune conditions
- Inflammatory bowel disease (IBD) — reducing GI inflammation
- Asthma and respiratory inflammation
- Joint inflammation — inflammatory arthritis (not typically for osteoarthritis long-term)
- Cancer treatment support — particularly lymphoma protocols, where prednisone is a key component
- Addison’s disease (hypoadrenocorticism) — during acute crises and sometimes for maintenance
- Allergic bronchitis
- Brain and spinal cord inflammation
- Severe acute allergic reactions — as part of emergency treatment
The dose and duration vary tremendously based on the condition being treated. Anti-inflammatory doses are much lower than immunosuppressive doses. Your veterinarian will tailor the treatment plan to your dog’s specific needs.
How Does Prednisone/Prednisolone Work?
Prednisone (after conversion to prednisolone in the liver) acts by binding to glucocorticoid receptors inside cells, which then regulate the transcription of numerous genes. The key effects include:
- Anti-inflammatory: Suppresses the production of inflammatory mediators including prostaglandins, leukotrienes, and cytokines. Reduces swelling, redness, heat, and pain at sites of inflammation.
- Immunosuppressive: At higher doses, suppresses immune cell activity, reducing the body’s attack on its own tissues in autoimmune diseases.
- Anti-allergic: Reduces the allergic inflammatory response including histamine release and eosinophil activity.
These effects are powerful but come with trade-offs, particularly with long-term use, as corticosteroids affect nearly every organ system in the body.
Species note on prednisone vs. prednisolone: Dogs can convert prednisone to prednisolone efficiently in their liver, so either form works. Cats cannot reliably make this conversion, so cats should always receive prednisolone rather than prednisone. If you have both dogs and cats in your household, be aware that the correct formulation differs between species.
Dosage
Prednisone/prednisolone dosing varies enormously based on the condition being treated. Your veterinarian will determine the exact dose, frequency, and tapering schedule for your dog.
| Condition | Typical Dose Range | Frequency | Duration |
|---|---|---|---|
| Anti-inflammatory (mild allergies, mild inflammation) | 0.25-0.5 mg/lb (0.5-1 mg/kg) | Once daily | Short course, then taper |
| Moderate allergic dermatitis | 0.5-1 mg/lb (1-2 mg/kg) | Once daily | Short course, then taper |
| Immunosuppressive (autoimmune diseases) | 1-2 mg/lb (2-4 mg/kg) | Once or twice daily | Weeks to months, with taper |
| Lymphoma protocols | Per oncology protocol | Varies | Protocol-dependent |
| Addison’s crisis (acute) | Emergency dosing by vet | IV/IM initially | Transition to maintenance |
Weight-based examples (anti-inflammatory dose range):
| Dog’s Weight | Low Anti-inflammatory Dose | High Anti-inflammatory Dose |
|---|---|---|
| 10 lbs (4.5 kg) | 2.5 mg | 5 mg |
| 20 lbs (9 kg) | 5 mg | 10 mg |
| 30 lbs (13.6 kg) | 7.5 mg | 15 mg |
| 50 lbs (22.7 kg) | 12.5 mg | 25 mg |
| 70 lbs (31.8 kg) | 17.5 mg | 35 mg |
| 100 lbs (45 kg) | 25 mg | 50 mg |
Tapering is essential. When prednisone has been used for more than a few days, it must be gradually reduced rather than stopped abruptly. Sudden discontinuation can cause an adrenal crisis because the body’s own cortisol production is suppressed during corticosteroid therapy. Your veterinarian will provide a specific tapering schedule.
How to Give Prednisone/Prednisolone to Your Dog
- Available as tablets (1 mg, 2.5 mg, 5 mg, 10 mg, 20 mg, 50 mg) and liquid suspension.
- Give with food to reduce the risk of stomach upset. Corticosteroids can irritate the stomach lining.
- Give at the same time each day for consistent levels.
- Follow your veterinarian’s tapering instructions exactly. Do not adjust the dose or stop the medication on your own.
- If you miss a dose, give it as soon as you remember. If the next dose is near, skip the missed dose. Do not double up.
- Your dog will likely drink more water and urinate more frequently while on prednisone. Ensure constant access to fresh water and more frequent bathroom breaks.
Side Effects
Prednisone side effects are dose-dependent and duration-dependent. Short courses at low doses cause fewer issues than long-term, high-dose use.
| Common Side Effects | Serious / Long-Term Side Effects (Contact Your Vet) |
|---|---|
| Increased thirst (polydipsia) | GI ulceration or bleeding (especially if combined with NSAIDs) |
| Increased urination (polyuria) | Iatrogenic Cushing’s syndrome (with chronic use) |
| Increased appetite (polyphagia) | Diabetes mellitus |
| Panting | Muscle wasting and weakness |
| Restlessness or behavioral changes | Skin thinning, poor wound healing |
| Weight gain | Secondary infections (bacterial, fungal) |
| GI upset | Ligament and tendon weakness |
| Adrenal suppression | |
| Calcinosis cutis (calcium deposits in skin) |
The “three Ps” — polydipsia, polyuria, and polyphagia (increased thirst, urination, and appetite) — are the most common and expected side effects and occur in most dogs on prednisone. These typically resolve after the medication is tapered and discontinued.
Drug Interactions
Prednisone has numerous important drug interactions:
- NSAIDs (carprofen, meloxicam, aspirin): Concurrent use carries a severe risk of gastrointestinal ulceration, perforation, and hemorrhage. A minimum washout period of 5-7 days is recommended between stopping one class and starting the other.
- Insulin: Corticosteroids raise blood glucose and may require insulin dose adjustments in diabetic dogs.
- Diuretics (furosemide): Increased risk of electrolyte imbalances (hypokalemia).
- Phenobarbital: Increases corticosteroid metabolism, potentially reducing effectiveness.
- Vaccines: Immunosuppressive doses may reduce vaccine effectiveness. Discuss vaccination timing with your veterinarian.
- Cyclosporine and other immunosuppressants: Combined immunosuppression increases infection risk.
- Aspirin: Enhanced GI and bleeding risk.
Contraindications
Prednisone/prednisolone should be used with caution or avoided in:
- Dogs with active GI ulceration
- Dogs with systemic fungal infections (corticosteroids can worsen fungal disease)
- Dogs with diabetes mellitus (use only when benefits clearly outweigh risks; requires close glucose monitoring)
- Dogs currently receiving NSAIDs (concurrent use is contraindicated)
- Dogs with active, untreated infections (immunosuppression can worsen infection)
- Pregnant dogs (corticosteroids can induce premature labor)
Storage
- Store at room temperature, 59-77degF (15-25degC).
- Protect from light and moisture.
- Keep in original container.
- Liquid formulations may have specific storage requirements — check the label.
- Keep out of reach of children and pets.
Cost & Availability
Prednisone and prednisolone are available as inexpensive generic medications.
- Approximate cost: $3-$15 per month for most treatment courses
- Available at: Human pharmacies (with veterinary prescription), veterinary clinics, online pharmacies
- Tablet strengths: 1 mg, 2.5 mg, 5 mg, 10 mg, 20 mg, 50 mg
- Liquid suspension available for smaller dogs requiring precise dosing
- Among the most affordable prescription medications in veterinary medicine
Frequently Asked Questions
Why does my dog drink and urinate so much on prednisone? Increased thirst and urination are the most common side effects of prednisone and occur in the majority of dogs. Corticosteroids affect the kidneys’ ability to concentrate urine, leading to increased water loss and compensatory drinking. These effects are dose-dependent and typically resolve after the medication is tapered and stopped. Provide plenty of fresh water and allow more frequent outdoor access.
Can I just stop giving my dog prednisone when they seem better? No. If your dog has been on prednisone for more than a few days, abruptly stopping can cause serious problems including adrenal crisis. The adrenal glands reduce their own cortisol production during corticosteroid therapy, and they need time to resume normal function. Always follow your veterinarian’s tapering schedule.
What is the difference between prednisone and prednisolone? Prednisone is a prodrug that the liver converts to prednisolone, the active form. Dogs make this conversion efficiently, so either drug works well. Cats and horses cannot reliably convert prednisone, so they should always receive prednisolone. If your dog has severe liver disease, your veterinarian may also prefer prednisolone to ensure adequate active drug levels.
Is prednisone safe for long-term use in dogs? Long-term prednisone use can be necessary for conditions like autoimmune diseases and certain cancers, but it carries significant risks including Cushing’s syndrome, diabetes, muscle wasting, secondary infections, and skin changes. When long-term use is needed, veterinarians aim for the lowest effective dose, often using alternate-day dosing and combining with steroid-sparing agents. Regular monitoring is essential. Your veterinarian will work to balance disease control with minimizing side effects.
Can my cat take my dog’s prednisone? No. Cats cannot efficiently convert prednisone to its active form (prednisolone). Cats should always receive prednisolone, not prednisone. Additionally, the dose will differ. Never share medications between pets without veterinary direction.
Sources & References
- Merck Veterinary Manual - Corticosteroids in Animals
- VCA Hospitals - Prednisone and Prednisolone
- PetMD - Prednisone for Dogs
- FDA - Corticosteroid Use in Animals
- American Kennel Club - Prednisone for Dogs
Verification Notes
Prednisone dosing ranges (0.5-4 mg/kg depending on indication) are consistent with standard veterinary pharmacology references and the dosing research compiled for this site. The species-specific guidance that cats and horses cannot efficiently convert prednisone to prednisolone is well established in veterinary pharmacology literature and the research data (human-medicines-for-pets.md: “CATS and HORSES cannot reliably convert — use prednisolone instead”). The NSAID-corticosteroid interaction warning and 5-7 day washout period are supported by the drug interaction data (Category 1: rated SEVERE risk) from the research. Tapering guidance reflects standard veterinary practice for avoiding iatrogenic adrenal insufficiency. This article avoids absolute safety claims and consistently directs readers to consult their veterinarian, per editorial guidelines.