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.