Hi guys, just want to ask your opinion.

My 8 year old German Shepherd/doberman mix has been a little less hungry lately. Up to about last month he would be raping the food bowl empty within minutes. but now a days he seems to not want to eat.. like no appetite.

I have tried changing brands/flavor and even added rice to the palates. Initially it was okay, but now his back to no appetite.

Any thoughts why? His still pretty active and all, happily pulling himself during walks/runs.

Thanks!