He likely ate something that hurt his digestion...

Please call around and see if a vet will work with you on payment arrangements.

If your parents are still just wanting to put him down, see if you can find a no-kill shelter and explain the situation. If there is anyone who can help, they will know about it!

Phone your vet and describe the symptoms, and see what they say.

I'm sorry - this is NOT minor - but it can be easily treated, usually, unless his intestine has been torn.

Also, if you go to Google and type in "Low cost vets in _____________" (put name of state in the blank), that would be a good place to start.

GOOD LUCK!