I have a Shiba Enu, 9 years old, who has tumors also. We have both kinds, fatty ones on the skin and Cancerous ones in her rectum lymph nodes.
Here's what we have done:
1. The fatty ones was very easy and a kind of miracle. I felt a big bump on her thigh and she was not walking normally. So I started rubbing Castor Oil on it and she even licked my hand with the oil. Beyond my surprise the bump went away in 3 days. This has happened twice already.
2. For the cancerous ones, we are giving her IP6 one pill twice a day crushed and mixed in her food. We gave her Colloidal Silver intially in her water 25% CS, she drank it eagerly, now she does not touch the water with CS. So we stopped. We also are doing the Budwig protocol, a mix of Cottage cheese, Flax oil and freshlly crushed Falx seeds. She is fairling well with all this. She is also getting Iodine in her food two to three drops in the morning meal and Vitamin C and half Brazil nut in the evening food.
Hope all this helps your Dexter. Emmy my dog is lively, but we know that she is hurting with tumors in her rectum, especially when she poops.