Hi, I understand your concern. I don't take in adult cats, they are all kittens up to about 5 or 6 months and the older ones have usually had their vacs. Alot of the time I actually know of people that are wanting cats so the turn around can be as little as 24 hours. I never have more than 2 extra's and if it is 2, they are from the same litter. I keep them away from my own 2, who are perfectly healthy until i have wormed and flead them.
Yoda was actually not that well when i took him in, he'd been born in the garden and the lady said she thought the mum had cat flu I think he may well have been taken from her to soon as he is very clingy. I took him to the vets as soon as I realised something was very wrong. His problem now is his tummy, he can't absorb his food even tho he's eating and drinking. That is what the tests are going to be for.
I know I'm not expert, and I don't have the best "facilities" but if you saw some of the places I've had kittens from then you'd know them being with me is the better option!! They have everything as new, bowls, blankets, beds etc to avoid anything being passed on. I do the best I can by all the kittens that come to me, Yoda is the fist one that has been poorly in anyway. And its breaking my heart to see him like this.