Last year our 11 year old lab had what appeared to be a "stroke" and was near death. We had a local at-home vet come over and she prescribed a bunch of different "hard" drugs and most importantly, showed us how to rehydrate her with subcutaneous fluids. The dog improved but never returned to normal. In desperation, to make her last days more comfortable we started her on CBD oil (not hemp oil. hemp oil basically contains no CBD). We used Full Spectrum CBD Tincture. 50mg CBD per ML of oil. We ended up at 2ml twice a day. Under the tongue worked best, because she was having a difficult time eating. All I can say is that it seemed to make her more comfortable. It didn't miraculously make her better, but had we to do it again, we would.
Also, this winter I was hunting quail in New Mexico for almost 2 1/2 months. Inevitably our 7 year old lab got into a few cactus. We were able to locate and remove most spines, but a few seemed to get into her feet and ankle joints. Took her to a local vet and his diagnosis was "yup", she has cactus spines. He recommended trying to surgically remove them only if they started to fester. They never did, but we started giving her 1ml of 50mg/ml CBD for about a week and she definitely started moving better and not showing any signs of tenderness or lameness. As others have noted the CBD industry has gone crazy. It is basically unregulated. About the only thing that is regulated is that the hemp it is made from must have less than 0.3% THC. We buy our CBD from
https://www.lazarusnaturals.com/ They provide test information for all lots they sell. I'm not 100% confident in them, but they seem better than most CBD suppliers. You really don't have to buy pet-specific products unless it makes you feel better. The dosage for the oil tinctures is in mg/ml so it is easy to figure out.
Last, there are studies being conducted on the efficacy of CBD for various issues with canines. I believe Colorado State University is doing some on its effectiveness for seizures. Their are hunting veterinarians that have published information online regarding their personal use of CBD for their own dogs. At this point, though, it comes down to what you want to try. As far as I can tell, it is pretty benign and from our personal experience, seems to have some positive effects for pain management and anxiety.