Post-op war of the pussycats!

[mumchkin]

Last week our 5 year old cat had a bladder obstruction and was critical in the pet hospital for 5 days. After 3 operations and a bit of a touch and go time of it, he came home on Saturday.
We have another, slightly younger female cat who pined for him the whole time he was away, however on returning home it’s like she completely doesn’t recognise him.
To be fair, he smells smelt just awful – combination of open catheter and the hospital itself, so to her, he probably is a whole new cat.
Fear of the imposter soon turned to aggression (hissing, growling) so we separate them at night and when we’re at work and supervise them when they’re in the same room.
Does anyone have any tips on how to mend the rift, or is it simply something that will improve when he heals up and smells better (at the moment he is wearing an Elizabethan collar so he can’t wash himself – I give him a little wipe each day, but can’t eradicate the smell entirely).
Would love to hear your pussycat wisdom – my first post on here so many thanks in advance.

I think it's just a matter of time as you say. She will def be feeling like he is an imposter.

This happened when my kitten was spayed and got sent back in another carrier. We kept them separated and within a week all back to normal aside from the odd hiss. Might take a bit longer for you re the collar/smell.

You can get some pet remedy in a plug in and spray bottle, my vets use it quite a bit. If you spray some on your hands and rub it over both cats it should help.

Thanks for the responses. They are slowly improving, 9 days in. Able to be in each other's space a bit more with just a couple of flare ups (always from her, he just kind of takes it on the chin). I think once he's back to normal, things will improve.