My 10 yr old Italian greyhound is too skinny, which since he’s a sighthound is a bit skeletal looking. He hasn’t lost weight (10.2#), but you can see he’s skinnier. His bones a very noticeable, and he feels lighter, like holding a bird. He’s still playful, energetic, and happy. His coat is shiny, soft, and smooth. The only thing off is his “weight”. Has anyone ever experienced this? Any suggestions to try and “bulk” him up?