Have you tried searching up the symptoms? Sound's to me the dog ate something toxic to it. Though i'd highly suggest having your vet tell you, and give you a proper diagnosis.
HELP. My neighbours 2 year old dog was unable to walk (back legs shaking and collapsing). He is also had diarrhoea and a very high fever. no sign of injury. Been to the vet who only gave him an injection for fever but not very helpful?
I would highly suggest seeing another vet. Medicine and treatment is usually a bit of guesswork even for vets. So you cannot know for sure what the problem is until you get opinions from two or three vets especially if there has not been any change since the first treatment.