Sounds like heavy metal or antifreeze poisoning. My golden retriever chewed up a bunch of linoleum at that age (high in lead). Caused lethargy, loss of balance and severe runs. Lethargy and balance problems went away in a week, Had off and on GI issues for life but was otherwise a perfectly healthy dog.
Wishing your dog the best, hopefully all will turn out ok.
My lab ate some wild mushrooms when he was about 6 months old and it landed him in the Emergency vet. He had to stay there for three days. Very scary, indeed.
I hope your dog is okay! I know what it's like having one sick and not knowing what's wrong until the vet checks them out or their lab results come back; please keep us updated.
Hugs for you and your dog. I am sure your parents and the vet are doing all they can. I spent over $300 on my kitten cat(she was starving herself and was so tiny),and I swore I would never do that. We do what we can regardless of the cost,and I bet your family is the same way.
I was thinking posions too.My mini pin was all floppy one time,but I was able to clear him up with some charcol tablets(very handy!) and herbs,and he was good to go by the time we got to the vet.