They Need to Lose or Gain Weight
If your pet is over or underweight, it might be a good idea to switch her food to fix the problem. But this depends on how much your dog needs to lose or gain. If your medium or large dog is just 1 to 3 pounds overweight, you can simply reduce her current food by one quarter cup, Raditic suggests.
For dogs that need to lose more than 3 pounds, a weight loss specific diet might be the best bet, she says. If you reduce your dog’s diet too drastically, you run the risk of creating vitamin and nutrient deficiencies since “adult maintenance” dog food blends are formulated based on the assumption that you’re feeding the recommended amount, not a reduced amount, she warns. Weight loss specific diets are formulated to be fed at a reduced-calorie level.
“Prescription weight loss diets really do have the ability to safely achieve weight loss so you’re not creating deficiencies,” Raditic says. “There are extra antioxidants, supplements, fiber, and other things in them that will help those dogs lose weight.”