Medical exam necessary for suddenly aggressive cat

Dear Cathy: I have a 7-year-old male tabby mix named Sam that I have had since he was 5 months old. He is neutered. For the past two to three months, he has started biting me after being in “lovey mode,” where he purrs and rubs against my head, neck, face or chest. These attacks seem to be happening more often these days. He mostly lies around the house and occasionally plays.

Then, out of the blue, he will launch himself directly at me and bite down hard. Sometimes, he will dig his claws in me as well. I have tried spraying him, yelling “no” and batting him away, but nothing works. Also, I usually never know when he’ll do this, so I don’t always have a spray bottle near me. Sometimes, he is biting so hard that it’s difficult to get him to let go without making him think we’re playing. Is this something I need to address with a vet? — Caitlin, St. Louis

Dear Caitlin: Yes, a medical exam is essential for all aggressive cats — especially cats who have not displayed this behavior before and who are suddenly doing it at 7 years old. I know from experience that getting bitten by an aggressively behaving cat can be very painful.

There are many reasons cats can be aggressive. Petting-induced aggression is relatively common and occurs when repeated petting arouses, irritates or excites them in some way. They bite or swat you to tell you they have had enough. In these situations, you must learn how many strokes it takes to trigger the behavior and keep your contact under that limit.

With redirected aggression, an external stimulus causes the cat to lash out at the nearest bystander because he can’t get to the source of his agitation. An example of this would be your cat seeing another cat outside and then turning and expressing his frustration toward you with an unexpected swat or bite.

However, since he didn’t behave like this as a kitten and has been doing it for only a few months, I would be concerned it’s a physical or mental health condition, like thyroid or orthopedic problems, adrenal dysfunction, cognitive dysfunction or neurological disorders, to name a few. Even food or medication can cause aggression issues.

So, please take Sam to the vet for a thorough exam. The sudden onset seems to point to a health problem, but if the doctor thinks it’s a behavioral problem, he can prescribe medication and recommend a behavior specialist for a consultation.