Ros when Lexy fell and dislocated her knee, and then injured her other knee with trying to bear her own weight, our vet gave me Metacam. It is linked to her weight and age, but I was told only once a day, up to 4 drops with food and lots of water to help the inflamantion of her ligaments and the surrounding tissue. AFter her surgery the vet said it was ok to give her 4 drops with her food.
I only ever gave her 4 on teh first day when she was really in pain, and it helped her straight away, and then two days after that I dropped her down to 2.5 drops each day.
AFter both her surgeries she got a little Metacam each day for about 4 days also around 2.5 or 3 drops.
Like any medication prolonged use can cause damage to kidneys (same as us humans), but since Lexy only had it sporadically and only when she really needed it, she came out fine. Thomas is only 17 (only!) so this is a good thing you can do for him. Your vet would not prescribe something that would be harmful. Also play it by ear...he may not need it every day etc.
Quality of life. I still have my 10 ml bottle and it goes where Lexy goes if I have to be away.
Hope Thomas does ok...poor little mite.