the same thing happend to me about 5 year ago with a salukixbullgreyhound, it was horrible, the vet said 'theres nothing we can do, your dog is dying, everything was failing, its kindneys its heart EVERYTHING!' i couldn't believe it, we took the pup '7months old' home and gave it a chance, i had it on my bed and it started fitting, by 5 the next morning it had died! i never got another dog for 2 year! ..mine was caused by stinking scruffy rats underneath nextdoors shed, he was leaving bits of food in the bowl sometimes and i just left it for him, the rats must of urnined on the food or summit