Patrice..if the bones are all able to be felt I am guessing your boy should be around 55lbs though you can’t go just based on height..bone structure also comes into play but 55 is probably a good start.
I would use Abady granular. Almost 800 cals per cup he will gain. For poodles who wont gain weight I start with 1 cup dry am and pm mixed with 1/2c Abady then increase to 50 50 etc until he gaind the needed weight. I would also look out for addisons disease as some of the early signs are genrral malady as well as lack of appetite and weight issues. Standard poodles are one of the most affected breeds.
