What is Prednisone and Why is it Prescribed for Cats?
Prednisone is a synthetic corticosteroid that mimics the effects of cortisol, a hormone naturally produced by the adrenal glands [1.3.6]. It is a powerful medication used in veterinary medicine for its potent anti-inflammatory and immunosuppressive properties [1.3.2, 1.3.4]. At low doses, it reduces inflammation, swelling, and itching, while at higher doses, it suppresses the immune system [1.3.1].
Veterinarians commonly prescribe corticosteroids for a wide range of feline health issues, including [1.2.2, 1.3.2, 1.3.5]:
- Allergic reactions and skin conditions (e.g., itching, hives)
- Asthma
- Inflammatory Bowel Disease (IBD)
- Autoimmune diseases (e.g., lupus)
- Arthritis and joint pain
- Certain types of cancer, such as lymphoma
- Adrenal gland disorders like Addison's disease
How Will Prednisone Make My Cat Feel? The Immediate Effects
For many cats, the initial feeling after starting prednisone can be one of significant relief. Because the medication acts quickly to reduce inflammation, a cat suffering from painful joints, itchy skin, or breathing difficulties may feel better within hours or days [1.2.6, 1.3.2]. This can manifest as a return to normal activity levels, improved mobility, and a better overall demeanor.
However, this relief is often accompanied by a distinct set of behavioral and physical changes. The most commonly reported effects are a noticeable increase in thirst, urination, and appetite [1.2.2, 1.2.5]. While these can be startling, they are expected side effects.
Common Behavioral and Physical Changes
- Increased Thirst and Urination (Polydipsia and Polyuria): This is one of the most frequent side effects [1.2.4]. The drug affects how the kidneys handle salt, leading to increased water retention and, consequently, thirst [1.2.4]. You'll need to provide plenty of fresh water and ensure the litter box is cleaned more frequently [1.7.5].
- Increased Appetite (Polyphagia): Prednisone can trigger the hunger center in the brain, making your cat seem constantly hungry or ravenous [1.2.4, 1.8.4]. While this can be beneficial for a cat that has lost its appetite due to illness, it requires careful management to prevent significant weight gain [1.2.4].
- Behavioral Shifts: Owners may notice changes in their cat's personality. Some cats become lethargic or depressed, losing interest in play or their usual routines [1.5.1, 1.5.4]. Others might exhibit restlessness, anxiety, or even aggression, although this is less common in cats than in dogs [1.5.2, 1.5.3, 1.5.5].
- Panting: While more common in dogs, some cats on prednisone may pant [1.2.2, 1.3.2].
Prednisone vs. Prednisolone: A Crucial Distinction for Cats
It is critical for cat owners to understand the difference between prednisone and its counterpart, prednisolone. Prednisone must be converted by the liver into prednisolone, which is the active form of the medication [1.4.2, 1.4.5]. Cats are known to be very inefficient at this conversion process [1.4.2, 1.4.3, 1.4.6]. Because of this poor absorption and conversion, veterinarians almost always prescribe prednisolone directly to feline patients to ensure the medication is effective [1.4.5].
| Feature | Prednisone | Prednisolone |
|---|---|---|
| Form | Inactive drug that requires liver conversion [1.4.5] | Active form of the drug [1.4.2] |
| Bioavailability in Cats | Poor; cats cannot metabolize it effectively [1.4.4, 1.4.6] | High; readily absorbed and utilized by cats [1.4.4] |
| Veterinary Preference | Rarely used in cats [1.2.2] | The standard choice for feline patients [1.4.5] |
| Use in Liver Disease | Avoided; puts stress on the liver [1.3.2] | Preferred choice for pets with liver conditions [1.4.2] |
Understanding Long-Term Side Effects and Risks
While effective, steroids are ideally used for the shortest duration possible at the lowest effective dose [1.2.2]. Long-term use (several months or longer) increases the risk of more serious health issues [1.2.1, 1.2.6]:
- Suppressed Immune System: Steroids weaken the immune response, making a cat more susceptible to bacterial, fungal, and viral infections, especially urinary tract infections (UTIs) [1.2.1, 1.2.4].
- Diabetes Mellitus: Corticosteroids can increase blood sugar and cause insulin resistance, potentially triggering diabetes, particularly in predisposed cats [1.2.2, 1.2.4].
- Iatrogenic Cushing's Disease: Prolonged high doses can lead to a condition that mimics Cushing's disease, with signs like a "pot-belly" appearance, thin skin, and hair loss [1.2.4, 1.8.2].
- Gastrointestinal Ulcers: Steroids can irritate the stomach lining, increasing the risk of ulcers and bleeding [1.2.2, 1.2.5]. It's often recommended to give the medication with food to minimize this risk [1.3.5].
- Muscle Wasting: Chronic steroid use can lead to the breakdown of muscle tissue, causing weakness [1.2.2, 1.5.3].
Safely Administering and Weaning Off Prednisone
NEVER stop prednisone or prednisolone abruptly. The medication suppresses the adrenal glands' natural production of cortisol. A sudden stop can cause a life-threatening withdrawal, sometimes called an Addisonian crisis [1.6.2, 1.6.5, 1.6.6]. Your veterinarian will provide a specific tapering schedule to slowly reduce the dose, allowing the adrenal glands to resume normal function [1.7.1].
Close monitoring and communication with your vet are essential throughout treatment. Keep a log of your cat's appetite, water intake, urination, energy levels, and any new symptoms [1.7.1, 1.7.2]. Regular blood work may also be necessary to check for impacts on the liver and blood sugar [1.7.2].
Conclusion: A Balancing Act for Your Cat's Health
So, how will prednisone make your cat feel? Initially, it is likely to make them feel much better by relieving the symptoms of their underlying condition. However, this powerful medication introduces a new set of physical and behavioral changes that must be carefully managed. The benefits of inflammation control must be weighed against the risks of side effects, especially with long-term use. Working closely with your veterinarian to monitor your cat's health, adhere to dosage schedules, and properly taper the medication is the key to using it safely and effectively.
For more information from an authoritative source, you can visit the VCA Animal Hospitals page on Prednisone/Prednisolone.
