Not working with their veterinarian – Get your vet to help you figure out exactly how much weight your dog needs to lose, then have a look together at the food you’re going to feed or have them recommend one. That way, you can understand the amount of calories each cup or can of food contains. Your vet can even compute your pet’s daily calorie needs based on current weight and activity levels and then adjust downward for weight loss.

It’s also good to have your veterinarian on board at the start to ensure that you’re not mistaking routine chubbiness for an actual medical problem. Also, your veterinarian can guide you regarding what is a safe rate of weight loss for a cat — most experts agree that about 1 pound per month is safe — since rapid weight loss can increase the chance of fatty liver syndrome, a dangerous and potentially fatal condition.