New to this forum and just thought I'd share my story of redirected aggression so as to maybe help cat owners who may suffer from this in the future.
My cats Hannah and Nova were best friends- no aggression to be seen. One day, a stray walks into sight and Hannah FLIPS out on poor Nova- screaming and swatting at her like she was fighting for her life. Nova escaped unscathed luckily, but Hannah would not calm down for literally 7 hours. No one could even walk past her, let alone touch her without her lunging. We separated Nova and finally lured Hannah into her crate and we brought her to the vet that day. She was prescribed amytriptyline (Elavil) and some behavioral modifications including separating Hannah for a bit and slowly reintroducing the two. After a nightmarish time of trying to pill Hannah and eventually spending a ridiculous amount of money on a transdermal compound and all sorts of essences (Safe Space, Feliway, etc.) to no avail, we consulted a different vet who suggested that Prozac tends to work much better for aggressive behavior ( and it's cheaper!). Willing to try anything to get our old Hannah back, we picked up the prescription only to find a bottle of pills- my boyfriend and I were so dismayed, Hannah is literally IMPOSSIBLE to pill...even the vet said so- they said she clamps down her jaw like they've never seen! We tried hiding it in food, treats, tuna juice, etc, but Hannah just wants to eat her dry food- even as a kitten, she never really liked wet food or treats. I almost cried- did I mention we were also in the process of moving into a house undergoing renovation...noisy, scary renovations? Not a good move for my scaredy cat.
Long story short, we finally were able to pill our finicky cat- we crushed the pill, put it in some cream cheese (or sauce from wet food as the consistency will hold the pill better), and schmeared it on her front paw. She was confused but immediately began licking it off- effectively consuming the medicine. We almost cried. We've been pilling her this way twice a day for over a month now. She hates the taste (it's VERY bitter) but she's so much happier these days.
Prozac has been a lifesaver for Hannah (and us)- she no longer growls or gets the aggressive look and after months of separation with no effective reintroduction, our fur babies are back together- and Hannah actually cuddled with me today, which is something she exclusively does with my boyfriend! I think the move away from the crime scene helped in the end, but I'm so grateful for Prozac- there was even a stray in our yard today and Hannah looked a bit spooked but didn't touch Nova (who actually got screechy herself). They were easily separated for a half hour to prevent any fighting from Nova and all is calm now. Such a miracle.
I know when we were first going through this, I searched the internet endlessly for answers- I hope this helps someone!