It may be the heat that is affecting his appetite.You may try another type of dog feed,maybe something in a can that smeels strong,some type of fish perhaps salmon or sardines.This may stimulate his appetite.Hope this helps,good luck and good hunting.
if he eats scraps aggresively he dont like the dry food your feedin. if hes the only one that dont like your feed try a lil cat chow mixed. if he picks at the scraps you got sum stomach issues.i would give him a couple metronidazone pills.be over it in a day.maybe a lil sulmet in the water for a couple days also helps. if he wont eat then shoot him