"What is the best ratio of cbd/thc for a 12 year old cat with a cancerous tumor? She’s about 9lbs. "
I’m sorry to hear about your cat. I would recommend that you start at a very low concentration of THC, e.g. 20:1, then work your way up until it seems a little too strong, then back up one step. The extra THC should help alleviate pain, improve appetite, reduce nausea, improve mood and possibly combat the tumor more effectively.