Mercy Showed Nonrecognition Aggression Towards Eddie
When Annie and Eddie went to the Morris Veterinary Clinic for their one year check-up, I made a mistake. It didn’t even cross my mind that when we returned from the vet visit there would be a problem with Mercy. We had no difficulty assimilating Mercy into our home with Annie and Eddie late last year. But what I didn’t think about was the fact that Annie and Eddie were in an enclosure right beside Mercy when we boarded them while Paul and I attended the Friskies. So when we came home, all three cats were familiar with each other, they had the clinic smell on them and each others scent from being in their carriers and riding side by side on the way home. Once we were in the house, everything went smooth and all cats got along.
So….maybe that is why I didn’t even think about what would happen when Annie and Eddie returned from the clinic this time. But unfortunately, Mercy began to hiss and growl at Annie and Eddie. Annie was more, “What’s your problem?” and Eddie ran under the sofa. I said to Paul, “oh boy, Mercy is exhibiting nonrecognition aggression towards the kittens.” Paul said, “What?” and I said, “Mercy doesn’t recognize Annie and Eddie because they smell so different from their vaccines and being at the clinic.”
Nonrecognition Aggression Between Cats
Nonrecognition aggression happens when one cat becomes aggressive toward another cat that shares the home after a period of separation. Although the cause of nonrecognition aggression is not certain, it is thought that the newly aggressive cat may be confused by the other cat’s smell.
As humans, this might be hard to understand because the returning cat will look and sound the same. But a cat’s sense of smell is an important part of their communication. Your cat rubs her cheek against an object to deposit her scent. When your cats rub against and groom each other, this is an exchange of their respective scents. Even though Mercy does not groom Annie or Eddie, they still exchange their scents by rubbing up against each other, sharing beds, blankets and eating side by side.
When Annie and Eddie came out of their carrier with unfamiliar scents clinging to them, imagine Mercy thinking that two strange cats just invaded his territory. The hissing and growling began and we needed to put a plan in motion immediately.
What to look for in your aggressive cat’s behavior
Aggressive behavior in your cat can include hissing, growling, taking a swipe, chasing and cornering and possibly biting. Mercy’s behavior showed hissing, growling and then chasing Eddie into the sun room and cornering him behind the Cat Power Tower. There can also be constricted pupils, hair standing up along the shoulders and a fat tail, and the appearance of getting ready to pounce on the returning cat.
What to do if you experience nonrecognition aggression between your cats.
- Do not let the cats resolve this issue on their own. Cats do not solve problems through fighting. Remember cats only fight as a last resort. As both predator and prey, your cat is hard-wired to avoid conflict that can cause injury.
- If the aggressive cat is in attack mode, distract the cat by clapping hands loudly, placing a divider such as a large piece of cardboard or blanket between them. You can try squirting the aggressive cat with a water gun if needed.
- Route the aggressive cat into a separate room so that the cat can calm down. You might need to cover the aggressive cat with a blanket to help calm him down and reducing your risk of injury. It might take several hours or even overnight for your cat to fully calm down.
- Do not try to calm down the aggressive cat, let them calm down on their own. An upset cat may lash out towards any person or animal who gets too close. If need be, prepare to keep the aggressive cat confined overnight with food, water, toys with familiar scents and a litter box.
We scooted Mercy into the sun room and closed the door. We then closed Annie and Eddie in the bedroom. We provided Mercy with all the things that comfort him, his food, water, toys, and a clean litter pan. Then we closed the door and decided to let him spend the night in the sun room to calm down.
Annie and Eddie were then allowed out of the bedroom. Both kittens did not understand why Mercy was in the sun room and they would walk over to the glass door, sit down and watch him. It was a good sign that Mercy didn’t swat at the glass and gnash his teeth at them.
- In the morning, we placed Mercy’s breakfast on one side of the glass door and left the door open just a crack with a door stopper. We then placed Annie and Eddie’s breakfast on the other side of the glass door and all three cats ate together. They exchanged sniffs through the crack in the door and there was no hissing or growling.
We opened the door, they all exchanged nose taps and life went back to normal.
How to Prevent Nonrecognition Aggression Between Cats in the Future
When Eddie returns to the vet later this week, I will make sure I take the proper precautions this time. I will keep Eddie separated from Mercy until he has fully recovered from his treatment and we are able to remove the clinic’s smells.
I will take one of the cat’s fleece blankets and rub it all over Eddie to transfer his scent before we leave for the clinic. Then I will make sure to transfer Annie’s scent onto the blanket too. When we return, I will take the same blanket and transfer Eddie’s scent to the blanket so that both his and Annie’s smell are on the blanket as well as his new smell with lingering smells from the clinic.
I will take extra precaution to place Mercy in the sun room until Annie and Eddie are reunited and then go through the same steps we used above to reintroduce Mercy to Eddie.
I will provide food, water and litter pans in separate locations to allow all the cats to come and go as they please until things return to normal.