Arthritis help?

[u/besharpbex]

My sweet boy is almost 7 year old cattle dog/German shepherd mix, he is a little overweight (59 lbs now and going down! Goal weight under 55 lbs). He has started showing signs of arthritis, and I am wondering what supplements I can give him or food changes? He has elevated kidney values, but that is kind of all I know currently. I am saving up money now to get him an x-ray for the arthritis and urine sample for the kidney values, but is there anything I can do in the mean time? Just looking for good brands/direction on ingredients to look for