I have two cats, female and male. They have fought in the past but it has recently started to get much worse. We have started to keep them separate and only let them see each other when they can be monitored. However, despite everything we try, they continue to fight. What should I do?
Sorry to hear about your troubles, having a multicat household can be tricky.
The synthetic F3 pherimone such as Feliway has been shown to be useful in situations where there are prexisting issues that may cause anxiety. However, the evidence on how well they work is questionable. There have been promising studies to suggest that they help on their own. However, the numbers are quite low in this study. It might be worth having a diffuser in your house to see if this helps the situation.
General Tips for Mutilcat Households
This was also discussed in a conference for the BSAVA. Here are the notes on what should be considered in any multi-cat household:
The cats’ personality: While many cats can live in social groups, some cats simply are unable to. A very territorial or very anxious cat may never be able to accept another cat in its territory.
Age and gender of both cats: Introducing a kitten may be easier than introducing an adult cat. At approximately 18 months of age cats become adult and, along with that, become more territorial. Gender may also need to be considered. Two male cats are more likely to fight than two females or one of each gender, but all other factors, e.g., personality type, should be taken into consideration.
Space and territory: The current cat will be expected to share its territory. This can be threatening for both cats and cause anxiety, stress and aggression. Within the household there should be enough space that conflict can be avoided, and environmental enrichment, e.g., using height with shelves and ledges that cats can use to increase security, should be discussed.
Resources: Owners should ensure that each cat has enough resources. Cats should not have to be restricted by having to share a food and water station. Toileting facilities should also be increased to one litter tray per cat plus one, i.e., three litter trays for a two-cat household.
Infectious disease: Increasing numbers of cats brings increased chances of infectious disease. Infectious diseases such as calicivirus and herpesvirus should be discussed and vaccination recommended. Households which contain many cats, especially breeding cats, should also be aware of other infectious diseases such as infectious peritonitis.
Introducing a new cat: A gradual introduction beginning with simply scent swapping should be advised before any visual introduction. Using products such as synthetic F3 pheromone (Feliway; Ceva Animal Health) may also help in the introduction process.
Lastly, all situations are different and a behavioral veterinary specialist is recommended to better understand your environment and help find a tailored solution for your specific situation if your cats continue to fight.