My cat hisses at new kitten but no puffy tail. What does this mean?

Separate Lilly from the kitten for a few days. Gradually reintroduce them. Start with a closed door between them so they can hear and smell each other. Progress to seeing each other but without physical contact. Once they are acclimated, try short periods of supervised contact. Use a pheromone prodcut such as Feliway Spray or the plug in diffuser to decrease any anxiety or aggression.

Here is a great article on introducing a new cat to the household. https://www.petcoach.co/article/5-steps-to-introducing-your-cat-to-a-new-feline/ You might want to back up a few steps and try to start the introduction over from the beginning. The second thing you can try is to help Fiona deal with the anxiety of the new kitten by using Feliway, which is a cat pheromone that can be calming. It is available in a diffuser that is plugged into an outlet and is great for a room in the home. It is also available as a spray, which can be used on towels, or the most common locations Fiona likes to spend time. https://www.drsfostersmith.com/product/prod_display.cfm?pcatid=8906 https://www.drsfostersmith.com/product/prod_display.cfm?pcatid=37241 Another product I like is Composure, which is available as a little treat. https://www.petco.com/shop/en/petcostore/product/vetri-science-composure-feline-bite-sized-chews If these do not help, you might consider discussing prescription medication for anxiety with your veterinarian. Thanks for using PetCoach.

This is very normal behavior. Make sure you provide plenty of litter boxes and food and water bowls to decrease the stress and competition of the kittens. Also, you can put some feliway diffusers in their room to help calm them. Feliway is a cat pheromone to help calm them but it doesn’t work on everyone. Give them some time and hopefully they will start to warm up to each other. I hope this helps!

I would try a Feliway spray, diffuser or collar. It is a pheromone that helps with relaxation and anxiety. There are also supplements for anxiety. Set up separate areas for feeding and two litter boxes so they each have their own space with an area that they both have access to. Usually over time they will adjust if left alone. If she’s still aggressive there are prescription medications to give her for a little while to help her adjust so please discuss this with your veterinarian. Thanks for using Petco Pet Education Center, formerly Petcoach to help you care for Kaji.

It does take time for the existing cat to get used to a new addition to the house, and I recommend introducing them slowly to each other. Take the kitten, and put her in her own room with her 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 kitten's room while the kitten 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 kitten out of her room, and see how she 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 kitten in her room when you go out until they are comfortable with each other.

I would recommend getting a Feliway diffuser to help settle the cats while this introduction goes on. Jazzmin may be showing misdirected aggression if she smells the kitten on you. Here are some articles to try to help make introduction go smoothly. https://www.vca.com/news/introducing-kittens-older-cat/ https://vcahospitals.com/know-your-pet/bringing-home-your-new-kitten https://www.feliway.com/ http://www.peteducation.com/article.cfm?c=1 2137

It may take time for Lilly to accept your other cat even though she is the smaller new cat. Some cats just don't do well together so if this behavior continues or gets worse I would recommend either talking to a veterinary behaviorist (if there is one in your area) or considering finding someone who can provide Lilly a great life as an only cat. Thank you for using Petco Pet Education Center, formerly Petcoach.