I recently added CBD oil for my senior. She is already on NSAIDS, Adequan, Dasuquin, Boswellia, Longevity, golden paste and gabapentin. I discussed potential benefits of CBD oil with my vet prior to trying it, and his feeling was "it can't hurt". He told me there is no research showing how or why it helps, or even if it does. But he has heard enough anecdotal evidence not to brush it off. My girl has been on it for about six weeks, and there is a noticeable lack of crying out in pain from her. Before the CBD oil, nights were rough. She would try to move and be completely unable to do so, and be in so much pain... it was heartbreaking. I haven't heard her cry or have the same kind of struggle since adding CBD oil. Is it a miracle cure? No. She still has arthritis and spondylosis. She still hobbles around. She still can't go for long walks or play the way she used to. But I do think it has given her a better quality of life. My vet also agreed that it seems to be helping her, and to keep her on it. If you are going to try Canna-Pet, get the actual oil, not the capsules. I noticed a much bigger difference in how she handled pain with the oil.
I will say that gabapentin was the one drug we added that added the most immediate, long lasting relief for her. I wish we would have started her on that sooner. The Adequan worked great for a while, but then the effects became less and less noticeable. I still give it to her, though I don't know that it is helping anymore. I agree with Magwart... if that had been started earlier, I think it could have halted some of the progression of the arthritis.
Does your vet do acupuncture or laser therapy? Those have been extremely helpful to my girl, as well.