My cat suddenly attacks our other cat after a flea collar. Why?

Thanks for using Petco Pet Education Center, formerly Petcoach! This is possibly because she smells differently. I recommend a product called Feliway which can help decrease stress and anxiety associated with environmental changes and stressors. You may find this online or at your local pet store. It usually works great in this type of scenarios. Good luck and have a great day!

It may be due to illness or injury. It can also be redirected (or displaced) aggression. This is when one cat is unable to directly respond to a perceived threat and "vents" on whoever is closest. This is usually an owner or another pet. Never handle or grab your cat if she is displaying aggressive tendencies. This can lead to a serious bite or scratch. Schedule an exam with your vet to rule out medical causes. If they are indoor cats, provide a ' cool down' period by separating them. Keep stray or strange cats away from windows or doors and out of your yard. Control what your cat sees by closing doors or drawing the blinds. Consider using pheromone products to decrease anxiety/stress level in the house. Search www.pet360.com for pheromone products.

This happens quite a bit actually. Could be territorial aggression - she left and now he is trying to tell her the house is his OR it could be that he feels threatened due to the way she smells when she returns. I suggest you start using some Feliway products. I would spray the carrier when you take the cats to the vet and use the diffusers (multicat) in the house. ( https://www.feliway.com/us ) ( https://www.feliway.com/us/Why-Use-Feliway/how-to-stop-cats-fighting )

Keep them separated for a few days. Gradually introduce one to another then introduce the third. A pheromone product such as Feliway spray or plug in diffuser may decrease any anxiety or aggression in the home. As the instigator, have Ripley examined by your veterinarian to diagnose illness or injury. Either can cause sudden behavioral changes. (Love the names for your trio. "Alien", great movie franchise)

A sudden behavioral change in cats that previously got along with no other changes to the environment can sometimes indicate issues such as underlying pain or illness. Bringing the cats in for an exam is a good first step to rule out any health issues that could be causing the aggression. If they check out healthy, adding in some pheromone diffusers can help with inter-cat stress. Making sure each cat has their own access to food, water, litter, places to hide, etc can also help decrease tensions.

I hate to hear that. This situation can very very stressful and it's hard to know why this is happening. It's possible Kyo is sick and his odor has changed. It may be worthwhile to have him examined by the veterinarian to make sure everything is ok. It's also possible the cats are seeing or smelling another cats outside and this is causing stress and bullying behavior. Wipe down doorways and windows to eliminate odors. Here are a couple articles to help with cat aggression and stress: https://www.petcoach.co/article/5-tips-to-handle-an-aggressive-cat/ https://www.petcoach.co/article/causes-of-stress-in-cats/ You can help relieve stress by setting aside 30 minutes a day for vigorous play for each aggressive cat, provide climbing opportunities with cat shelves and cats treats, use a pheromone diffuser and provide separate litterbox and feeding stations. Lastly, your veterinarian can provide medications or a special diet called Calm which may help the cats. Best of luck and please feel free to post any additional questions.

Hello. The biggest problem is trying to identify or understand what set Daisy off. Perhaps an odor or sound, or she may have sensed another cat outdoors that frightened her. Since it can be difficult to know, the best thing to do is be proactive. I would immediately purchase a couple of Feliway room diffusers & put them in the room the incident occurred, & any other rooms Daisy frequents. Feliway emits a cat appeasing pheromone which can calm a nervous kitty. You can buy these online or at most pet retailers. Start with this along with a good physical exam by your veterinarian. It is possible that she could have an underlying condition like arthritis or even a urinary tract infection that caused her significant pain. Hopefully, this will never happen again. Thanks for using Petco Pet Education Center, formerly Petcoach.