Cat Aggression: Cat Fights After Vet Visits

Kittens fighting
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One of the most common forms of intercat aggression occurs between cats that formerly were best friends. This type of cat attack can be emotionally upsetting to the victim cat as well as the cats' owners. In many instances, the unexpected attack results from redirected aggression when the aggressor lashes out at a surrogate target since the actual target can't be reached.

A common scenario occurs when one cat from the household leaves home to go to the groomer or veterinarian.

When the cat returns home, former kitty friends either snub or outright attack the treated feline. It almost appears that the cats don't recognize each other.

Actually, they don't.

Scent Communication Rules

Cats communicate with vocal, visual and scent cues, and the cat's unique scent serves as the ultimate kitty identification tag. When they sleep together, groom each other, or simply rub against one another in passing, cats share scent. Think of this communal scent as a sort of color-coded system that identifies them as belonging to the same family.

When a cat visits the veterinarian, he smells weird upon his return. He's been handled by strangers, perhaps bathed or treated with medicines that smell funny, and may even be ill and smell unhealthy. He's wearing a foreign smelly name tag the other cats don't readily recognize. Those "stranger danger" kitties won't let him get close enough to establish his identity.

When the household cats greet the returning cat with hisses, he naturally gets his back up and acts defensive, too. This situation can escalate beyond the posturing, particularly if the ill cat continues to make trips to and from the vet clinic.

How To Stop Aggression After Vet Visit

Confident kitties usually work out their shortsightedness in time.

But you can speed up the process, and prevent worsening of relationships, with these tips.

  • Try to schedule routine veterinary visits for your cats at the same time. That way, they all smell similar after being handled by clinic staff.
  • When a cat is ill, his body chemistry can make him smell funny and other cats often change their behavior toward him even before the vet visit. Segregate an ill cat from the others, especially if they're treating him poorly. Cat-bashing just raises the stress levels of all involved, and the longer it goes on, the more time it will take to reverse.
  • Segregate the kitty returning from the vet in a room alone for at least half a day. That gives him time to self-groom and remove all the icky clinic smell from his fur, which is so offensive to his cat buddies. It also allows the treated cat time to decompress from the stress of the vet visit so he's less on the defensive. All the cats may be more willing to become reacquainted after a cooling off period. Don't rush to re-integrate the kitty to the rest of the pack. He may need extra time to get over the trauma of the vet visit, and there's no urgent need to thrust him back with the rest right away. 
  • Use a hand towel to pet-pet-pet the other household cats. Pay particular attention to the best-friend cat, rubbing the towel against his cheeks. This gathers the best-friend cat's signature scent, which can then be rubbed over the vet-visit cat to help re-establish communal family scent.
  • Monitor the first several hours of the cats' interaction, and segregate the treated cat immediately should there be a cat-bashing / hissy incident.
  • For some situations it may be helpful to scent all the cats with a strong-smelling pleasant odor that not only makes them alike, but also distracts them from cat-bashing. For instance, rub your hands with the water from canned tuna, and stroke the back of each cat. That should encourage them to self-groom and potentially groom each other-creating a renewal of the family scent.