Sold me a sick kitten

I also bought a cat from Maureen Sheehan in Swampscott, MA. The cat was born 12/30/2008 and was noted to under weight when I got her. Weighting only 2.12 ibs. at 12 weeks old. My vet just did the cat's yearly physical and she was noted to be losing weight, so the vet requested a stool sample which was submitted and was fine but after reading this article, I am concerned about her having problems that might be related to the bladder and kidneys. I hope I don't have the same heartbreak that the previous writer did, I just phoned my vet and left her an urgent message to call me.