Help for our Adopted cat!

[PhilTG84]

6 days ago we brought home a tortoise-shell Persian from the SPCA. It would be polite to say the SPCA were not nice and didn't do a very good job. The cat sat in her own feces for 8 days, was never cleaned and only vaccinated when we were going to take her home. The day we adopted her (Monday, 19 September), she had teeth removed surgically and is on 14 days Clindamycin.

We're growing concerned that the cat has protracted diarrhea. The SPCA sold us Royal Canine, Feline Adult #27 for food, which she eats, but doesn't seem to enjoy. She's drinking regularly, is very active, talkative and quite content.

She had been at the SPCA for 8 days but had been on the streets for months prior. She is declawed and as a result of being on the streets and quite ill, is very thin (5.2lbs at adoption). Should we be concerned? Is this the result of a new environment, new people, surgery and the antibiotics?

I've never had a cat before and this is rather distressing! I appreciate people's help!