Drug therapy in cats: a systems approach.

In the second part of this 4-part series, drug therapy in cats is discussed by use of a systems approach. Specifically, drugs that can be used safely for treatment of disorders affecting the feline gastrointestinal, central nervous, respiratory, cardiovascular, and urogenital systems are described. Many drugs that are used in dogs can be safely used in cats according to the same or similar dosing regimens. Several drugs that have traditionally been considered inappropriate (eg, morphine derivatives, primidone) can probably also be used, if cautiously, in cats. In contrast, use of several drugs that are safely used in other species should be avoided in cats (eg, selected emetics and antiemetics, phosphate salt enemas, and selected urinary antiseptics). Cats are more sensitive than dogs to the adverse side effects of a variety of drugs (eg, aspirin, digoxin, selected antiarrhythmics), and extra precautions must be taken when these drugs are used in cats. Finally, several drugs are used for the treatment of illnesses that tend to be unique to cats (eg, taurine and calcium-channel blockers in selected feline cardiovascular disorders).