My cat is aggressive after sister had kittens. Can I save their bond?

Thanks for using PetCaoch! It’s not uncommon to hear about behavior like Alyssa. It can take a lot of time and patience for them to get along but here are some tips for decreasing stress for Alyssa in the short term. -Feliway- calming cat pheromone- comes in many forms from pet stores or online. 

 - Adding a litter box. Studies show that the ideal number of litter boxes for a home is #of cats +1 . This is regardless of how clean you keep his current litter box. 

- making sure she has plenty of “high space”. The safest (and therefore least anxiety-inducing) place for a cat is up. If you don’t already, get a cat tree or put up a shelf or two that she can go perch on. 
 Feeding them in separate rooms with two or three water bowls throughout the home is also a good idea as perceived competition for resources is a common problem in cats. Best of luck to you and your kitties!

This may be difficult to correct but it generally can be done. Continue using the diffuser. Try switching litter boxes, beds, and rubbing each cat with the same towel to try to get them to smell like each other. Here are some links which may be helpful: https://www.petcoach.co/article/7-ways-to-calm-an-anxious-cat/ https://www.petcoach.co/article/bringing-home-a-new-cat-or-kitten/ Here is a great article about cat's instinctual needs: https://www.petcoach.co/article/why-every-cat-needs-a-place-to-climb/ Setting aside 30 minutes a day for vigorous play for both cats or switching the food to Royal Canin Calm may help. The veterinarian can also prescribe medications which can help with aggression. I hope this helps and please feel free to post any additional questions.

Hello. Unfortunately, this is not a friendly family group. Cats do not often form strong bonds with their offspring & she may be feeling a little threatened by having them around as they get older. It may be a good idea to either find homes for the kittens, or consider spaying the mother cat. This may alleviate some of her anxiety. Hopefully, things will even out for her soon. Thanks for contacting Petco Pet Education Center, formerly Petcoach.

There are likely going to continue to be aggressive towards each other due to hormones. If you don't want them to fight it is best to have them both spayed. You cannot force them to like each other again. Things have now changed after the one had kittens.

Thank you for submitting your question regarding your cats. This can be common after a trip to the veterinarian. The kitten will be covered in different smells. This can cause stress in the older cat resulting in her to act out in aggression. Keep them separate unless they are fully supervised. They should be fine with each other in a few days. In the meantime, you can try a pheromone diffuser to help calm them. Feliway is a good brand. I hope this information helps!

She is likely to become more protective when the new born kittens arrive and it is unlikely she will become more accepting of the older kittens at this stage. Ensure she has a quiet area to have the new kittens undisturbed y other cats (including her previous offspring)

If the female is being treated for lymphoma, she will be smelling differently when she returns home from treatment, and Mochi will see her as a stranger, leading to the aggression. I would separate the cats, and slowly reintroduce them to each other. Take the cat who is aggressive, and put him in his own room with his own food, water, and litter box. Keep the door closed, and for a few days, feed them both treats on other side of door so they associate each other's smell with a good experience. Then let the other cat in the aggressive cat's room while the aggressive cat is in a cat carrier. They can smell each other, but not be in contact. If either becomes upset or show signs of aggression, remove the second cat from the room, and try again later. Praise them when they interact appropriately. When they are interacting well with each other through the carrier, you can let the aggressive cat out of his room, and see how he interacts with the other cat. Praise them when they interact appropriately, and separate them with any sign of aggression or upset. I would get a cat tree with lots of shelves to give the cats vertical space to get away from each other. I would keep the cat in his room when you go out until they are comfortable with each other. I hope this helps!