Along with what Margot has told you about food, I would also add some PLAIN
Yogurt.....Usually, I suggest low fat
yogurt...You can feed it as a snack or with a meal.....
It will help replenish the GOOD bacteria that the antibiotic is going to kill & also will sooth the tummy......Very nutritious, too!!! Let us know how he's doing....Karla
P.S. If you need some help selecting a quality dogfood, let me know......You may be feeding a food that isn't good for him anyway.....