Dr. Susan Nelson, a veterinarian and assistant professor of clinical sciences at Kansas State University, said there are several guidelines to follow when feeding your pet to ensure that it maintains good health.
Just like human food packages, many cat and dog food packages contain nutritional information, Nelson said. Packages often list the kilocalories, protein, fat, carbohydrates and fiber per cup. In recent years, manufacturers started listing some nutritional information, including calorie content, for dog and cat treats.
"In the past, we didn't know how many calories were in various treats," Nelson said. "Now that's becoming more available, and that's because more pets are becoming obese and their owners are asking for that information. Pets are overeating and underexercising, and they're eating too many high-fat foods and treats."
Nelson said these plumper pets are not only benefitting from improvements in pet food quality, but also from the increased calorie content caused by the higher fat content of many premium diets. But does that call for owners to start counting calories for their pets?
"It's important to count calories if the pet is overweight, but it's probably not necessary if you have a pet that is of normal weight," Nelson said. "If it starts to get pudgy, you need to take a look at how much exercise it is getting, how much food you are feeding it, and how many treats you're giving it."
Calories from treats should be no more than 10 percent of your pet's diet. If owners want to count their pet's calories, Nelson said, veterinarians can make diet calculations for dogs and cats. The overall recommendation for the amount of food to feed your pet is based on several factors, including the type of food you are feeding your pet, your pet's metabolism and how much exercise it gets.
"Generally, I tell people that unless your pet is overweight, go with the guidelines on the food bag," she said. "If the pet is a little overweight, you should feed it for its ideal weight and not for its current weight."
Nelson said if you want to compare different pet food brands' nutritional information, you have to look at the nutritional content calculations based on the dry matter content. Often, this is not listed on the bag, so you might have to look online or call the company to find the information.
"What most bags list is the nutritional analysis that is formulated on an as-fed basis," she said. "To truly compare the nutrient content of foods, you have to look at the dry matter basis, which takes out water content."
Nelson said it's typically best to start by following the feeding guidelines on the bag. She said people shouldn't assume that feeding one cup of one diet is the same as feeding one cup of another, because pet foods can vary greatly in calories. She also suggests using a standard 8-ounce measuring cup for dry food.
To determine if a pet is too heavy or light, Nelson said owners should look at several factors. You should not be able to see the animal's ribs, but you should be able to feel them easily with a thin layer of fat over them. When you look at the animal from the side, its tummy should tuck up at the flank area and not hang in a straight line.
If you look over the top of a dog, you should see an hourglass shape where it's broad at the shoulders, narrow at the waist and broader at the hips. If the dog starts to thicken out, you should cut back on its calories and/or have it exercise more.
"In general, make sure you're feeding the appropriate diet for the life stage of your pet," Nelson said. "If your pet is pregnant, a puppy or kitten, has special health condition needs or is a senior, there are foods formulated that best meet the nutritional demands for that condition."
There are breeds of dogs and cats that have high metabolisms and have trouble putting weight on, Nelson said. For these pets, there are pet foods that have higher fat contents because it gives the food more calories. If the pet is extremely overweight, it might need diet food along with other recommendations. These foods are lower in calories, nutritionally complete and often contain extra fiber, which helps make the animal feel full. Conversely, if you feed the animal much less of their regular food, your pet is not going to get enough of the nutrients it needs.
Nelson said many people do not realize how many calories they're feeding their pet because they don't account for table scraps or treats. These hidden calories can add up significantly over the day and be the main contributor to obesity. Putting your pet on a diet requires attention and effort from the whole family, she said. If you have a small child, inside pets are going to eat everything the child drops, and those calories will add up.
"Sometimes you'll try to put your pet on a diet, and then someone else living in the house will slip it treats," Nelson said. "You should talk with the whole family when putting your pet on a diet. Tell them the diet is necessary to keep the pet at a good weight, which in turn will make it healthier and can help it live a longer life."