Hi again, I'm so sorry you didn't receive an earlier answer. Your patience is greatly appreciated!
If this behavior started shortly after you got her spayed, he may have been stressed by the smell of the vet's office and medication, etc., that frightened him. He may not be going after her as prey, but because she doesn't smell the way she used to, before her surgery.
Another reason Ahmeer could be exhibiting this behavior is to assert his dominance and show her that he's 'Top Cat' in the household. This is not uncommon in multicat households.
He might be exhibiting 'redirected aggression' toward her, due to a frightening or frustrating event. If he was looking out the window, for example, and he saw flying insects or birds or even a stray/strange cat or unknown dog, he would take out his aggression on the furry companion or human closest to him, physically and emotionally. This is not uncommon behavior with cats. Here is more info:
To help alleviate the stress between them, you can get a Feliway plug in diffuser; this emits cat calming pheromones only detectable by cats:
There are other over the counter calming remedies; one is a pheromone collar and the others are oral:
NOTE: don't give both Rescue Remedy for Pets AND Composure treats at the same time--choose one or the other. Either is fine with the Feliway, because that's only emitted in the air.
Take an old t-shirt of yours and pet one cat with it, then the other cat, then, vice versa. This will make both cats smell the same and they will smell your secure, comforting scent on themselves and each other.
When they play nicely together, praise them highly and give each one a cat-healthy treat, so they associate the GOOD behavior with eating something pleasurable.
If you see Ahmeer stalking your girl, have prepared a covered can of coins or pebbles in a few rooms, or carry it around with you, if possible. Shake the can, which will startle Ahmeer and stop him in his tracks. Stand out of sight, because you want him to associate the sound with his actions, not YOU.
You can also sit on the floor with a throw pillow and as you see Ahmeer stalking, say 'NO' and gently push him back with the pillow. However, you must be consistent in this, so he learns his behavior is unacceptable.
As a last resort, you can discuss starting Ameer on a low-dose anti-anxiety or anti-depressant prescription medication. The is a variety to choose from. Ask about Clomicalm:
I would not recommend adding a new cat into the mix, at this point. I understand how disconcerting the fighting is when Ahmeer goes after your furry girl and it does add a great deal of stress to the household, but sometimes, the cats just have to work it out for themselves. Try giving them time apart for an hour or two, so it cuts down on the stress for you and your husband. You can put one cat in a room with food/water, litter, toys, bed, etc. and allow the other cat to roam freely throughout the house; then change and let the other cat roam freely without your girl having the fear the Ahmeer might attack.
I hope things improve soon with your two furry kids!
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