[TheNewGirl]

If you think your dog has cancer you need to take him to a vet IMMEDIATELY. Most vets, if you've had a long standing relationship with them, will be willing to work out a payment arrangement for expensive treatment. You are not only responsible for but legally required to provide proper medical care for your animal, that is the responsibility you took on when you took in the dog.

First find out if it's malignant or benign. If it is an aggressive form of cancer and you are unable or unwilling to pay for the surgery you at least owe it to your animal to man up and put him or her to sleep so that he or she can die with dignity rather then enduring a slow painful death because you were unwilling to foot the bill for an exam.