You all remember me posting last week about a stary cat at my moms house that was pregnant that died. Well now we think she was poisioned by the neighbors because now my moms little wiener dog is dying too-much the same way as the cat.
That is awful if it is intentional, but I had a cat once who ate a rat which had eaten rat poison that a neighbor had set out. Posions can sometimes unintentionally enter the food chain.
It could also be anti-freeze. Cats and dogs (and small children) sometimes get poisoned accidentally because it looks and tastes appeaking.
I hope your dog gets better, and that the vet can find the source of the poison.