I had good success with Dasaquin(sp). I find my two older girls do as well on Fresh Factors from Springtime (www.springtimeinc.com)If you buy on sale or buy enough to take advantage of their discounts, it comes out substantially cheaper.
Try a supplement that contains glucosamine, chondroitin, msm and hyaluronic (sp?) acid (a component of joint fluid).
Amazon carries a "chewable" tablet called total joint care; but my oldies call it a "spittable" tablet and so they get a horse supplement called HA Select that contain those ingredients and which is sprinkled on the food.
One of the vet schools (MSU, maybe?) tested & found the HA causes it to be effective in 24-48 hours. Glucosamine without HA takes a couple of weeks to build up a therapeutic level.
For us two-legged oldsters with similar issues, Osteo Bi-Flex has a formula with HA. And, yes, I am moving much better since I've been taking it.
Our 8 yr old boy has problem elbow and arthritis has set in over time. We've tried different supplements, foods, therapies (medical, homeopathic) all with limited long term results. The best advice I was given is to keep them lean & moving - just like I was told by my doctor for me. Good luck!
Try a supplement that contains glucosamine, chondroitin, msm and hyaluronic (sp?) acid (a component of joint fluid).
I give all my guys a joint supplement with those ingredients (Move Free plus MSM by Schiff - it's a human one I get at Sam's club ... none of mine have any trouble taking pills), along with Fish Oil and for the oldest one(s) vitamin C.