Aggression between housemates

Question
Hi Holly,

We have 3 felines in our household, 2-Tonkinese girls; Babie (11 yrs old), Mandy (9 yrs old), and 1- Black & white tuxedo male Joey (9yrs old). All are indoor cats while Mandy and Joey have been in the house for 9 years with Babie. All three cats are very affectionate and lap cats, while Joey is most like a dog in that he always wants to be in the middle of whatever we are doing and the door greeter. He loves people, and is always around unless there are small children in the area. Babie is also outgoing and connects easily with strangers. Babie is the most dominate and I would consider her to be the alpha feline in the house.
All has been well until about a month ago, when the cats were moved to the basement while the bimonthly housekeeper was in the upstairs cleaning. In the basement, a quiet safe area has been set-up with bedding, heater, litter box and water. They have been doing this routine for two years without any issues. While in the basement, Joey and Babie had an altercation where Babie was found cornered in the crawlspace after a fight with Joey who was standing over her and growling. He was in this stance for at least 30 minutes. Babie was soiled after defecating where she was sitting. I threw a blanket over Joey to calm him down and he then came to me. He was unhurt and started to purr after a couple of minutes.  Babie was also unhurt although there were tuffs of her fur in the area. She was pretty shaken-up and we separated Joey from the two girls for a day. We talked to the Vet about the incident, and she suggested we try the Feliway diffuser in the rooms to try and calm things down. This seemed to help with the demeanor of all the felines until two weeks ago, when they were placed in the basement once again during the housecleaner visit. It was des-a-vous once again, with Joey cornering Babie in a different part of the basement and her soiling herself again. I was away during this period while my wife was present in the house. We separated them for another day and reintroduced, but after a day, Joey now is aggressive towards Babie and can't be left without supervision.  We took Joey to the Vet's this week and had him checked out, he appeared normal, but has been itching lately and scooting across the floor. Joey has a food allergy and been eating a special prescription diet for the last 3 years. His food was changed during the Vet visit and testing done.  He   appeared normal in every way (overweight though) with the test results all normal except for two elevated enzymes which were not conclusive. Follow-up bloodwork to be done in a month. In the mean-time, Joey has been separated from the two Tonks and he has not seen them in two days. We alternate areas, bedroom for the girls, mudroom for Joey during the night and allow them access to the first and second floors during the day. Joey and Babie will sit in front of the door where the other cat is while they are roaming in the main part of the house intermittantly and cry at times. We spend time with them separately multiple times a day and my wife is home most of time.
This seems like introducing a new feline again, but they have been together for 9 years. I was planning on keeping them apart for a week, then cracking the door so they can see and smell each other, exchange rooms and facial scents for a couple of days and then monitored time together. I would appreciate any thoughts on what may have precipitated this change in behavior and increasing aggression between these two. What other suggestions do you have other then using medications. Thank you.

Answer
Hi Don,

I'm sorry to hear about your troubles with your cats.  There's two issues at work here--whatever happened, the trust is broken between the two who had the altercation, and even worse, you don't know what caused it, which makes it harder to correct or rehabilitate.  And two, because the basement is where it happened and nothing was done positive in the basement after the incidence, the cats will now view this as a negative place and the incident is more likely to reoccur when they're all placed back into the same situation.  It's also a possibility that what caused the altercation is something specific to the basement.  The Feliway is only going to help calm the cats in general, not rehabilitate the mind to change the behavior.  Medications and calming aids only help control the symptoms or environment and don't serve to correct or rehabilitate the behavior.  This process starts with retraining the brain to associate what was previously negative as positive.

The first thing I would do is separate and rehabilitate the cats, and then reintroduce each one to the basement separately, taking at least 15 or 20 minutes with each using food and toys to create positive experiences in the basement.  Remember to do each cat separately first.  As far as the cats, I have recently answered a very similar question regarding two sibling cats that started fighting after three years.  Please read the 'Brother & sister fighting after one got injured' response as well as the recommended reading, and then email me if you have any further concerns or questions at holly06petlover@yahoo.com  I wish you and your family the best, and hope the recommendations and information help.

Best regards,
Holly Martin