Rational use of corticosteroids in small animals

Using corticosteroid drugs in treating small animals, and ways of avoiding side effects

source: Kit Sturgess
In Practice vol 24 no 7, July/August 2002
starts p368, 6 pages long

Corticosteroids are mainly produced in the adrenal gland, and they may be prescribed for a number of conditions. Though they can be helpful, they can also cause problems if they are misused. Some animals, such as rats, rabbits, hamsters, and mice, and birds are sensitive to steroids, whereas others, like humans, dogs, cats, horses, pigs ferrets and guinea pigs, are relatively resistant to steroids. Marked lymphocytolysis can result from using glucocorticoids with species that are sensitive to steroids. Other potential side effects include changes in the skin and hair, such as thinning of skin, lethargy, mood changes, tachypnoea, weight gain, polyuria, hypertension, muscle weakness and decreased muscle mass, osteoporosis, body fat being redistributed, pancreatitis, and immunosuppression.

Glucocorticoids can suppress clinical signs, but are rarely cures, so should not replace specific therapies. Single doses of glucocorticoids that are intermediate or short-acting are unlikely to be harmful, except in conjunction with NSAIDs, or in the case of hypovolaemic animals. Three-day treatment periods are also unlikely to be harmful, except where high doses are involved.

Corticosteroids may both act as anti-inflammatories and imunosuppressants. They can delay diagnosis and inhibit wound healing

Adverse side effects can be avoided in a number of ways, such as by being careful with using glucocorticoids in animals that have intercurrent disease, or are pregnant. Doses should not be continually increased if there is no initial response. Side effects are more likely at higher doses, and with longer-term treatments.

Steroid treatments lasting over two weeks should end with tapered doses to avoid corticosteroid withdrawal syndrome. This syndrom is not likely to be a problem with treatments of under three days.

Lab tests may be affected by animals having been given corticosteroids, for example, urine concentrating ability may be decreased, and T4 levels may be reduced.