Protocel is a highly recommended alternative for pets, along with paw paw or graviola. I believe this site has links to veterinarians who use these therapies, as well as some information on the protocol.
http://alternativecancer.us
I know that protocel for pets has been discussed on Cancer Compass before. You might do an internal search on the site - keywords: protocel, dogs - you might be able to find some good information in past message threads.
I hope everything goes well.
Sincerely,
Tre