Mother cat hissing at daughter after being spayed.

Hi guys, just joined the site because we have a mother (Maple, about 18 months) and daughter (Teak, about 4/5 months) and have had them for about 3 months at home. They've always been very affectionate and playful with each other. Then yesterday we took Teak back to the shelter/vet to get spayed and microchipped. Brought her back home last night and Maple keeps hissing and growling at her!

It's been about 24 hours now and Maple is still really freaked out. I don't think she'll hurt Teak because while she's hissing/growling, she's the run who runs away!

I've just bought a Feliway plug in diffuser, anyone had any experience of those? Will also try distraction like mentioned above (although not with laser pen! Maple sat in the corner traumatised last time we tried that, she's a bit of a scaredy cat)

The first time I ever took Sammy and Garfy (persian brothers) to the groomer, it really freaked Sammy out.  They came home with their new dos and Sammy had a hissy fit as soon as they both stepped out of their respective carriers.  He went up to Garfy and sniffed him and hissed at him!  I'm sure he recognized his brother but he didn't recognize his smell.  It was horribly perfumey!  (After that, I asked for the oatmeal wash from then on.)  Sammy went crazy swatting and hissing at Garf and then he jumped up on my kitchen cut-through and ate a Prayer plant!  He went ape that day!  I had to call the breeder quickly to make sure he wasn't going to die!  

I think smells really do matter more to a cat than they do to us because they have a greater capacity for it.  

As I mentioned before on other threads, my kitty Nat (see my avatar, right side, the pretty belly) has had several ER visits.  Three of those visits were several nights long and each time he came back home, he was greeted by the others with a litany of hisses and standoffish behavior.  My poor Natty Boy!!!  He didn't feel well and then he had to be treated so badly when he finally got to come back home!

He did smell like the hospital, and he was hungover from IV valium and phenobarb.  Bless him.  It took several days to get back to normal.  

I'm sticking by the theory that a cat hisses at the returning cat because the latter cat smells like a cat in heat, a scent that probably rubs off pretty easy from the vet. So cat hisses and growls because -- she doesn't want to get raped!

You can rub a bit of vanilla, the real kind, under both of their chins.  This will help them to smell the same while the smell of the vet lingers.