If you decide to take him the the SPCA, make sure you get pre op bloodwork done, either there or by your regular vet. It will tell the vet if his organs can safely handle anesthesia. It is especially important in Yorkies since the breed is prone to liver disease. Anesthesia is processed through the liver.
The type of gas used is also very important for toy breed dogs.
Here is a sticky pinned in the Health section that is full of information:
http://www.yorkietalk.com/forums/yor...-protocol.html