My biggest regret with my elderly labrador was that I waited so long to put her on Metacam be honest. I was a vet student at the time used loads of supplements, dieted the poor creature right down on weight, swimming, hydrotherapy, j/d food.carthrophen injections etc...Then eventually when I noticed her losing more and more muscle over her back legs tried meloxicam(Metacam)....and seen a massive improvement in her comfort level within a few days..chronic pain is bad like that and Osteoarthritis causes chronic pain. The guilt was awful!
but I learned something very valuable... quality of life trumps everything.
Her quality of life was much better when she wasn't hurting. Weaning her down to a lower dosing schedule didn't work out very well for her...she was most comfortable on pain relief...over the next 3 years she stayed on the NSAIDS class of meds-metacam and its various generics,then previcox as well as keeping her supplements and cartrophen.. and went to heaven at 13 and a half...for a separate issue-she blew one knee- cruciate jumping out of the car and the second one went within a week :( and I couldn't put her through the surgery with her bad hips etc or keep her comfortable enough to manage on cage rest...still miss that dog!
If his quality of life is improved on pain relief then I would focus on looking at alternative pain medications if Metacam scares you.....but I really would reconsider your stance on that to some extent or even consider some of the newer NSAIDs that are even more targetted drugs..Previcox is one.
Metacam is contraindicated in kidney and liver disease to a certain extent...but if had normal bloods and he has been on it already and had 0 issues so far then the risk of issues longterm isn't very high due to the medications itself.
Most side effects, if you're going to have them, will be in the initial few weeks...that's when you find out if there's a preexisting issue or sensitivity there.
Vets are checking blood/urine etc yearly or 6 monthly is often to see if old age has caused any issues with the body that would mean we may need to consider alternative medications as the dog now has a hepatic or kidney issue as they age as much as to catch the very rare side effects...old age isn't a disease but it does predispose us to them.
The veterinary NSAIDs themselves have a low risk of long-term side effects if the patient is healthy. Do medications carry some risk. Always...all medications that are effective will have some risk. That's why they test them so rigorously...so we know what issues to look for with each med.
But in these sort of cases the quality of life benefit analysis sort of needs to be considered in comparison to the risk.
Personally, I don't rate Yumove in the same category as Metacam for pain relief at all. It's a nutritional supplement, not a medication. It does seem to be helpful to some dogs in the early stages of OA to increase mobility and can sometimes help reduce the doses of meds etc but it isn't pain relief and osteoarthritis is painful.
I'd focus on controlling the pain and work on the best quality of life.