My cat is hissing at me after new kitten. Is this a serious issue?

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.

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.

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.

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'm sorry to hear that Nala is having a hard time with the introduction of a new kitten. It certainly sounds like she is experiencing some anxiety as a result of having a new kitten added to her household. Since it sounds like you have done a good job of introducing Simba gradually and Nala is still not tolerating him, you might need to find some ways to decrease her stress. One option for decreasing stress is to add a Feliway Diffuser ( https://www.feliway.com ) to your house. This is a calming pheromone that will work for a month and may be beneficial for both cats. I have also had luck with Rescue Remedy ( http://www.bachflower.com/rescue-remedy-pet/ ) which can be added to the water. You could also consider calming music specifically for cats ( http://throughadogsear.com/tace/through-a-cats-ear-1-music-for-calming/ ). If Nala continues to hide in your bedroom, it may be time to take her to your veterinarian for a physical exam and discussion about possible anti-anxiety medication short-term. Hopefully if you can get her more comfortable around Simba, they can have a good relationship, but it commonly takes some time. Good luck! I hope that was helpful. Thanks for using PetCoach.

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.

It does take time. I can give you a method that has worked for me, but know hissing and growling is ok. It's her way of letting the dog know she isn't comfortable. Aggression is not ok (hitting and biting), but the behavior is ok. I would keep them in rooms separated by a door. This way, they can get used to the smells and sounds of each other without contact. Make sure your kitten has a litter box, food, and water in their room. You can also place a blanket with the dog's smell in the kitten's room, and a blanket with the kitten's smell in the odg's room. I would also consider get a Feliway for your kitten and a DAP for your dog. These are pheromone diffusers that help with anxiety and should also help ease the transition. Once both pets seem relaxed with the current situation, swap rooms placing the kitten in the dog's room and vice versa. You can do this switch several times over the course of the introductions. Once they are both comfortable with the smells of each other, it's time for them to meet face to face. I would introduce the dog on a leash to the kitten while she is in a cat carrier or on the other side of a baby gate. Reward the dog for being calm and quiet near the kitten. Once they seem comfortable with each other, the baby gate can be taken away. Make sure your kitten has a cat tree where she can escape from the dog as needed, and don't allow the dog to chase the kitten. I hope this helps!