CORTICOSTEROIDS
Corticosteroids are used to treat a wide variety of diseases. Common examples of corticosteroids include:
A. Prednisone/Prednisolone
B. Dexamethasone
C. Methylprednisolone
These drugs may be prescribed as tablets, oral suspensions, or as injections. Corticosteroids may cause a variety
of side effects. While these adverse effects are generally not serious, we feel you should be aware of them.
Potential Adverse Effects
A. Increased thirst & urination
a. Your pet will likely drink more water than is typical for him/her. As such, s/he will likely need to
urinate more frequently. This is normal for dogs receiving corticosteroids.
b. Marked increase in thirst is unusual in cats  should you observe this, please contact as soon as
possible.
c. Do NOT limit your pet’s water intake  this restriction may cause severe dehydration,
potentially adversely affecting the kidneys.
B. Increased appetite
a. Corticosteroids will likely significantly increase your pet’s appetite. However, unless your pet is
underweight, do NOT feed him/her more than usual. Should you feel you need to supplement
your pet’s diet and your pet has not been prescribed a strict diet, you may offer vegetables, lowfat rice cakes, and/or pieces of bran cereal.
C. Increased panting (Dogs)
a. This is very common for dogs, and is NOT a concern unless your dog has increased respiratory
effort.
D. Behavioral changes
a. Many dogs are lethargic are high doses of prednisone / prednisolone  it is important you are
aware of this potential effect, so you don’t ascribe the lethargy to underlying disease and/or
lack of response to therapy.
b. Uncommonly, pets may become restless and/or irritable.
E. Gastrointestinal ulcers (Dogs)
a. This adverse effect is more common with high doses of corticosteroids, in patients with
underlying gastrointestinal disease, and/or in those patients receiving certain concurrent
medications, particularly non-steroidal anti-inflammatory medications.
b. Monitor your pet closely for loss of appetite, nausea (evidenced by excessive drooling), vomiting
blood and/or “coffee-ground”-like material, and/or defecating tar-like feces. Should you
observe any of these signs, please contact a veterinarian for appropriate medical advice as soon
as possible.
F. Secondary infection(s)
a. As high doses of corticosteroids may suppress the immune system, animals receiving these
medications may have an increased risk for infection, especially if they are receiving concurrent
immunosuppressive medications.
b. Common sites of infection include the skin and urinary tract  monitor your pet closely for loss
of appetite, lethargy, vomiting, straining to urinate, and/or skin lesions.
G. Changes in skin/haircoat
a. Corticosteroids may slow hair growth, and as such, you may notice little to no hair re-growth
from shaved/clipped areas. Some dogs may develop dry skin with dandruff.
b. These changes will likely abate, and dietary supplements may help.
H. Diabetes mellitus (Cats)
a. Uncommonly, corticosteroids may induce diabetes mellitus in some predisposed cats. This
condition generally abates with a decrease in your pet’s corticosteroid dose and/or
discontinuation.
b. Please monitor your cat closely for increased thirst and/or urination, as well as weight loss
despite a healthy appetite. As always, please feel free to contact us with any
questions/concerns.
I. Increased insulin requirements
a. Diabetic patients concurrently receiving corticosteroids may require higher doses of insulin. If
your pet is living with diabetes mellitus, please continue to monitor urine glucose levels closely,
and adjust insulin doses according to your chart.
J. Thromboembolism
a. Corticosteroids may increase the risk for developing blood clots. This is a rare adverse side
effect except in those patients living with an underlying disease that further predisposes them
to developing blood clots.
K. Body conformation changes
a. Long –term administration of high doses of corticosteroids may cause muscle atrophy, muscle
weakness, and/or joint laxity. This generally does not occur if we are adjusting/weaning doses
appropriately, and as such, it is necessary for you to maintain contact with a veterinarian to
avoid this potential adverse effect.
Our goal when prescribing corticosteroids is to treat your pet’s disease while gradually weaning him/her to the
lowest possible dose to maintain control of the disease. Your pet’s veterinarian will provide you with a schedule
of how to appropriately reduce the corticosteroid dose.
Corticosteroids should NEVER be abruptly discontinued, as this may cause severe, potentially life-threatening
side effects. Please contact a veterinarian before adjusting your pet’s corticosteroid dose.
NOTE: Prednisolone is the active form of prednisone (prednisone is converted in the body to prednisolone).
Evidence suggests some cats lack the enzyme to accomplish this conversion, and thus, we generally prescribe
prednisolone for cats. Please be sure your preferred pharmacist dispenses the appropriate medication.