Guide to Pet Medications: Prednisone (Steroids) and Your Pet

Prednisone, and its close relative prednisolone, are among the most widely prescribed drugs in veterinary medicine. Due to the ring-like shape of their molecular structure, these compounds are called steroids. However, they are dramatically different from the anabolic steroids of bodybuilding infamy. A more appropriate term for drugs in this family is “glucocorticoid,” because they affect the regulation of glucose and are derived from a substance called cortisol (also known as hydrocortisone). 

Cortisol is produced in the adrenal glands, tiny organs that sit on top of the kidneys. We need cortisol to keep our energy high in times of stress. This substance can minimize inflammation at high doses.  At even higher doses, it can suppress the body’s immune response. Obviously, there are many medical uses for such a drug.

Why Is Prednisone Prescribed?

Your veterinarian might prescribe low-dose prednisone for “physiologic replacement,” which is when your pet can’t make enough glucocorticoid on his own.

A far more common use for prednisone is for its anti-inflammatory properties. Steroids minimize the body’s ability to create inflammation at the site of damage. They can be used to treat asthma, allergies (including those that manifest as itchy skin), certain inflammatory gastrointestinal conditions, arthritis, and orthopedic injuries.

At high doses, glucocorticoids can be used to suppress a hyperactive immune system (auto-immune diseases such as lupus) or as a comfort measure in treating cancer. 

How Are Steroids Like Prednisone Prescribed?

Steroids come in oral compounds, topical creams, and injectable formulations. There are short-acting and long-acting versions. Commonly prescribed glucocorticoids include prednisone, prednisolone, dexamethasone, triamcinalone, methylprednisolone, and many others. Your veterinarian will choose the drug and formulation that is most appropriate for your pet’s illness.

What Happens After Prednisone Or A Similar Steriod Has Been Prescribed?

If your pet has been prescribed prednisone or a similar steroid compound, it is very important that you follow your veterinarian’s instructions and do not deviate.

1. Hopefully, your veterinarian was able to obtain a diagnosis prior to starting treatment.  Why does this matter?  It is important to remember that glucocorticoid therapy does not cure disease!  It simply masks symptoms so that the patient feels better.  For example, prednisone does not cure allergies or asthma, it makes their symptoms tolerable. It does not cure cancer, but it can help the patient feel better and (temporarily) shrink certain tumors. Initiating treatment without a diagnosis might make it more difficult to obtain one later on…  
2. When first prescribed, there is typically a loading dose given until desired results are achieved. Then the dose is tapered down to the lowest effective level. It is common to decrease the frequency of administration until the medication is given every other day or every third day. Why? When the body detects prednisone taken externally, the adrenal gland won’t make any extra cortisol. Every other day dosing prevents the body from “forgetting” how to make its own cortisol. On the day when no drug is detected it will prompt the adrenals to get to work.  
3. Don’t ever stop your prescription cold-turkey or there could be life-threatening complications! Always ask your veterinarian how to properly taper the medication off.   
4. Your veterinarian will need to draw your pet’s blood on a regular basis while he is taking this medication. She might also recommend a urine culture to check for a urinary tract infection.  
5. Ask your veterinarian if your pet should be given any supportive medication, such as antacids to soothe any gastrointestinal side-effects of steroid use.  Some veterinarians recommend feeding the pet prior to dosing them to limit the potential for upset stomach.

Possible Short-Term Side-Effects of Glucocorticoids (Steroids)

The most common side-effect experienced is that of increased thirst, which leads to frequent or excessive urination. Your pet might also be hungrier and dogs might pant.

Steroid use can also lead to infections of the urinary tract or upper respiratory tract due to their effects on the immune system. Unfortunately, they can also cause a borderline diabetic pet to actually become diabetic.

Other possible adverse effects include gastrointestinal ulceration, bruising, calcium deposition in the skin, thin skin, hair loss, and weight gain.

Chronic Use and Contraindications

Long-term usage of steroids should be avoided due to the possibility of your pet developing hyperadrenocorticism, also known as Cushing’s syndrome. Glucocorticoids should not be used in pregnant animals and should be used with caution in diabetic animals and pets with cardiac disease.  Avoid using steroids concurrently with non-steroidal anti-inflammatory drugs (NSAIDS) in patients who are already immunocompromised or those who are currently healing from an infection.

Prednisone is an extremely useful and versatile drug.  It can be anti-inflammatory at moderate doses or it can be immunosuppressive at high doses. It can help treat a wide variety of illnesses but it also has the potential to harm if used inappropriately.

Follow your veterinarian’s instructions and report any and all side-effects you witness. Remember, the goal is to use the lowest possible dose for the shortest possible amount of time and then to taper the drug off completely.