My new female cat and old cat aren't getting along. What to do?

Hi there and thanks for using Petco Pet Education Center, formerly Petcoach! Congratulations on your new kitty! In these situations it is best to do introductions very slowly. Some suggestions I have for you are as follows: 1) Use a Feliway diffuser to reduce overall tension in household 2) Go back to the beginning and over the first week introduce by smell only (introducing cats to each others bedding or something that has their scent on it) 3) Then introduce by sight only but no direct interaction. Do this for a week 4) Finally introduce cats together but only with direct supervision and with plenty of escape routes for both cats. Only leave them together for a very short time at first 5) Have plenty of tall cat towers and other things for the cats so they can observe each other from a distance 6) Have at least 3 litter boxes in different locations and definitely continue to feed separately and have separate water bowls. I hope this is helpful! Good luck to you and Malish!

My guess is that you did not do a gradual introduction with them?? If not, you may have to go back and revert to doing that along with these other recommendations. ( https://www.americanhumane.org/fact-sheet/introducing-cats-to-cats/ ) I recommend you put some Feliway diffusers (Multicat) in your house and do some environmental enrichment for them. Usually these two things help. ( https://www.feliway.com/us/Products/FELIWAY-MultiCat-Diffuser ) ( https://www.feliway.com/us/Why-Use-Feliway/how-to-stop-cats-fighting ) ( thedrakecenter.com/materials/environmental-enrichment-indoor-cats ) Hope this helps. If you have more questions you can always opt for a private consultation where we can chat back and forth. That way you can ask as many questions as you'd like. Best wishes.

Just like some people, some Cats don’t get along. Trying Feliway diffusers in the house may decrease the stress level. These can be purchased at any major pet store. Also consider adding in tall cat trees and lots of hiding boxes to keep them happy. Best of luck and I hope there is more harmony in your household soon! Thank you for using Pet Coach.

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!

I am so sorry to hear about your kitties! I would recommend getting some Feliway multicat diffusers https://www.feliway.com/us/Products/FELIWAY-MultiCat-Diffuser which are a pheremone releasing product that can help these situations. A calming supplement such as Zylkene can also be helpful. Ensure the cats each have places they can hide/get away if needed as well as adequate numbers of litter boxes (one more than the number of cats in your household), water and food available where they can eat/drink without being disturbed by the other cat. If they are still fighting despite this, some training may be needed. You can read this article by a veterinary behaviorist for details on this: https://drsophiayin.com/blog/entry/feuding_felines/

I am not sure what you are concerned about as far as safety. I do recommend keeping new kittens quarantined away from other cats for 2-3 weeks so you can monitor them for any illness that could be incubating. It can take time for cats to adjust. Getting a new cat is like getting a new roommate. Sometimes it is a perfect match and sometimes you can't wait to move out! Giving them time and space to adjust is the best thing you can do right now. You will need to have separate spaces, each space with its own food, water, and litter box. Sometimes using a feline pheromone diffuser can help with stress, like Feliway or Comfort Zone. Here is an article you may find helpful: https://www.petcoach.co/article/5-steps-to-introducing-your-cat-to-a-new-feline/

The next step is to rotate rooms daily for at least 2-3 days. This allows the new cat explore the rest of the house while the resident cat spends some time in the new cat's room. This will give your resident cats a chance to smell the new cat and rub their own scent on objects. The cats should be fed in each area with wet food twice daily, and it is also good to play with the cats in each area at least twice daily. The practice of setting up a schedule of feeding treats of wet food, as well as a playtime routine, minimizes anxiety and makes the cats feel more secure. Keep the cats in separate areas for as long as it takes to allow them the chance to become desensitized to the smells and sounds of the cats in the other area. When they all seem particularly relaxed with this process, begin to expose them to the sight of each other. A good way to accomplish this visual introduction is to bring the new cat(s) in a carrier to meet your cats and sniff each other through the carrier wire door. Place the carrier on the floor and allow them to meet this way several times a day for about an hour. Continue these meetings for several days or until they remain calm in each other's presence. If and when the cats are able to stay calm in each other's presence during these meetings, it is time to let the new cat out into the rest of the house for a few minutes. The length of the visits can be increased gradually each day. Depending on the personalities of the cats involved, this process may take a few days or a few months. If it appears that any fighting maybe be close to occurring while you are supervising, put the newcomer back in his/her room and proceed more slowly. If those supervised play times go well, you can begin to allow them to cohabitate in your home. If any aggressive behavior occurs at any time, begin the introduction process again. It is very important to understand that this process can take as little as a few days, to sometimes much longer. It is all dependent on the cats involved. If things don’t go well right away... One of the most important steps to dealing aggressive behavior between cats is to recognize the different types of aggression and understand their underlying causes. A short list and description of some commonly seen aggressive behaviors include: chasing; ambushing; hissing; swatting; and/or biting. If you see these behaviors, seek help from your veterinarian. Most cats get along fine if the introductory process is done correctly. Please seek help from your veterinarian if you feel that things are not progressing well, or if you have other questions.