My two-year old cat occasionally hisses at my new one-year old cat when they are together. I got the new cat three weeks ago. They play together, but then sometimes for no reason I am aware of the older one hisses and looks angry. What could cause this and what can I do about it?
With any type of aggression, it is important to be sure that there is no medical reason for it. I recommend that you take your two cats to your veterinarian for full physical examinations. The doctor may also recommend bloodwork depending on the outcome of the physical exams. A number of physical problems can cause aggressive behavior in cats. These include hyperthyroidism, certain forms of epilepsy, and perhaps any condition that causes pain -- arthritis, impacted anal glands, dental problems, and many others. Various organic brain diseases such as tumors can also cause aggressive feline behavior. The veterinarian will be able to assess the health of the cats and if he or she finds that they are healthy, then the doctor may determine that the problem you are seeing is intercat aggression. Various studies have shown that most domestic cats in close proximity will hiss and swat at each other on some occasions. Intercat aggression may have a number of causes. These include conflicts relating to feline social hierarchy in the household, mating issues in unneutered cats, fear, territorial conflicts, and other causes that often are not well understood. To prevent injury, the cats should be separated when you are not at home to watch them. The aggressor should be placed in a less favored part of the house, like a spare bedroom, while the other cat may either have free access to the rest of the house or be placed in a favored part of the house. When the cats are together they should have different-pitched bells placed on their collars. These bells will help you to determine where the cats are and what they are doing. If the cats play well together and are quiet, they should be rewarded with food treats. Sometimes aggressive behavior between cats resolves within a few weeks or months. However, if the aggressive behavior continues, your veterinarian may decide to refer you for consultation with a veterinary behaviorist. The behavioral specialist can evaluate the nature of the aggressive episodes and recommend behavioral modification techniques and other steps as needed. In a few select cases, medication may help alter the aggressive tendencies. In your case, it may only be necessary for you to use food treats as rewards for good behavior. This positive reinforcement may diminish your older cat's hissing and allow the cats to play well together.
07/10/03
