Tranquilizers and Behavior Drugs for Cats
The best approach in treating a cat with a behavior disorder is to identify the underlying cause of the abnormal behavior and treat that cause using environmental and behavioral modification. In general, it is best to use drugs only when other methods have failed. The drug should be withdrawn from time to time to see if the problem behavior recurs.
Because of the potential for dangerous side effects, behavior drugs should only be prescribed and monitored by a veterinarian. The use of these drugs should also be part of a comprehensive behavior and environmental modification program. Many of these medications are not approved for use in cats and may also require compounding to get an appropriate dosage.
Before any medication is administered, the cat should have a complete physical examination and blood workup to identify any underlying medical problems.
Tranquilizers are useful for calming an injured or frightened cat and for relieving anxiety attacks caused by moving, shipping, mating, or other traumatic experiences. A side effect of tranquilizers is that they block cortical inhibitory impulses. That means a tranquilized cat may stop using the litter box or may bite and scratch at the slightest provocation. It can be difficult to do behavior modification with a tranquilized cat.
Acepromazine (Promace) has a general depressive effect. It acts on the pain center and relieves anxiety. It is difficult to do any behavior modification with a cat who is tranquilized, though, so this drug should only be used very short-term. It should not be the first drug of choice and many behaviorists avoid it.
Diazepam (Valium) is less depressive and much preferred for most behavior problems requiring a tranquilizer. However, diazepam has been shown to cause serious liver problems in some cats and should not be used routinely. Cats taking diazepam need frequent liver enzyme evaluations. This drug is successful for 55 to 75 percent of cats with inappropriate elimination problems, but the behavior resumes when the medication is stopped. Since diazepam is not an appropriate drug for long-term use, it is therefore not the best choice for cats with inappropriate elimination problems.
Medroxyprogesterone (Provera), megestrol (Megace), and other progestins have a calming effect and depress the pain center. They are useful in modifying aggressive behavior, particularly behavior with a sexual component. Effects are similar to those of castration.
Progesterones also are effective in treating urine marking and spraying, destructive scratching, compulsive self-grooming, and cannibalism. Side effects include cystic endometrial hyperplasia, mammary hyperplasia, pyometra, adrenal gland disease, weight gain, excessive drinking and urination, and diabetes.
Because the side effects are serious, these drugs have fallen out of favor for use in behavior problems with cats. When needed, they should be used only as short-term adjuncts to behavior modification.