My cat stopped using the litter box after a new kitten arrived.

It is possible. Ideally, in a multi-cat household you should have one litterbox per cat plus an additional litterbox in a neutral area. Try sprinkling a litterbox attractant in the box to entice him back. You can also use a pheromone product, such as Feliway Spray or plug in diffuser, to help decrease any anxiety associated with the new addition.

It can be stressful for cats to move into a new home. There are a few simple things you can do to help them litter train in your house. First, have at least 1 litter box per cat plus one; therefore, if you just have the two kittens, I would recommend 3 litter boxes. Second, make sure the litter box is large. The kittens will keep growing, and if it becomes too small, they won't use it. Third, some cats don't like covered litter boxes and some like them. You can try to boxes covered and uncovered, and see what they like best. I would recommend using the same litter that was used at their old home because they are used to the smell and texture. Make sure their litter boxes aren't close to their food and water, cats don't like to use the bathroom near their food source. While you are litter training them in your house, don't let them have free rein of the house when you are gone. Place them in a small room with their litter boxes while you are away from the house, and provide them with water and a place to sleep at the opposite end of the room from the boxes. Make sure you clean the litter box daily. If they continue to have problems going to the bathroom outside the litter box, it may be a health issue, and I'd recommend bringing them into your vet for a health check.

Cats can become stressed by other cats but they do often work things out eventually. There are a few things you can adjust to help decrease stress. Cats are sensitive to the type of litter, size of the box and location of the box. If you have more cats, you need 1 litter box per cat + 1 additional box. You should also have a litter box on every floor of the house. This article discusses different types of litter and litter boxes: https://www.petcoach.co/article/cat-litter-finding-the-right-fit-for-your-cat/ In general though, cats prefer large, uncovered litter boxes, clay-based clumping litter that is scoped every day and a private, quiet location. If you have other cats or dogs, if they can access the litter box, it may cause Luna to be afraid that she could find herself trapped in the box. Cats are a prey species in the wild and they still retain those instincts. Here is a great article about cat's instinctual needs: https://www.petcoach.co/article/why-every-cat-needs-a-place-to-climb/ Use a Feliway diffuser, set aside 30 minutes a day for vigorous play and/or switch the food to Royal Canin Calm. Most cats response best to combination therapy. The veterinarian can also prescribe medications which can help with anxiety. I hope this helps and please feel free to post any additional questions.

It may be something frightened him in the new location and he is looking for a safer option. I recommend having a second litter tray in the room he prefers as a back up. Trays should be in a quiet, undisturbed location, not near noisy or unpredictable things such as washing machines. A calming supplement can help also and it is important to encourage frequent, stress free urination by facilitating his preferred options to reduce the risk of urinary tract inflammation and irritation

I know this is not ideal. If you are able to place a litter box up there I would. That way she is still urinating in a litter box at least. When you do have more room, I would create a space just for her. Put 2 litter boxes out for her, give her a place to look outside, places to hide and climb on also. I don't know if your veterinarian performed a urinalysis. If they did then I would think about doing a urine culture. A urinary tract infection does not always show up on blood work and a urine culture will give you an answer. Has your veterinarian prescribed behavioral medication? This may be a good idea for Nyx also.It can take a few weeks for it to fully work but it is something I would think about. Thank you for using Petco Pet Education Center, formerly Petcoach.

Hi. I would recommend a few things. Uncover the boxes. Add a third box. And isolate them from each other for a bit. Then introduce, after showing them where the boxes are. Also recommend full exam and labs to rule out any medical potential causes for inappropriate defecation. Good luck.

I think placing one of the diffusers in the kitchen would be a good idea, as the pheremone will be most heavily dispensed near the diffuser. Also, it is recommended with litter boxes that you have one more litterbox than the number of cats in your household, so in a house with 3 cats it would be recommended that you have 4 litterboxes. This isn't always possible depending on the household, but it if is, you may consider adding additional litterboxes. Also providing places for the mother cat to hide or escape, including boxes/houses and cat trees/platforms can be helpful. Best of luck to you and I love the name Batman!