Obesity seems to run in families. Not just obese parents and their children but obese owners and their dogs and cats as well. To date, there has been no verified or established link between obesity and inherited genes. (See George A. Padgett, DVM. Control of Canine Genetic Diseases. Howell Bookhouse. New York. 1998.) When a dog breed is said to be “prone” to a disease, it usually referrs to some genetic factor, and to date none have been found. There is, however, a very strong link between obesity and diabetes in dogs (Delbert G Carlson, DVM and James M Giffin MD “Dog Owners’s Home Veterinary Handbook. 1992 Simon & Schuster MacMillan. Pp. 199-202), and there does seem to be a genetic basis for diabetes although it is, as yet, undetermined. Dogs with a thyroid deficiency are prone to obesity.
Dogs are called “Omnivores.” That means they will eat anything. Dogs do not discriminate between foods that are “good for them” and foods that are harmful. If a dog owner offers a dog or puppy grapes as a treat, the dog will not only eat them but also become quite fond of them. Large quantities of grapes can be lethal for dogs. The same is true of chocolate. Yet owners persist in feeding their dogs potentially harmful substances as treats.
Wild dogs or feral dogs are not obese. They simply don’t get enough food to become obese. Domestic dogs, companion animals and house pets, especially the smaller dogs, are all in danger of becoming obese simply due to the feeding and exercise practices of owners. Of all the breeds at dog shows, it is the black Labrador Retriever and the Bulldog that is more likely to be shown in an obese condition.
Dogs become obese for the same reason humans become obese; they eat too many high glycemic carbohydrates in their diet and they don’t get enough exercise to use the calories they eat.
The link between diabetes and obesity in dogs is similar to that for humans. A dog’s diet consists of proteins, fats and carbohydrates. Commercial kibble usually contains between 40 and 60% carbohydrate, 30% protein and 10 to 30% fat. (This distribution is similar to the USDA Food Pyramid recommended daily diet for humans.) Protein is needed to build and maintain muscles and all tissues of the body; fat is used to lubricate and feed all systems and carbohydrates are used for energy. The greater the carbohydrate intake, the more exercise is needed to burn it off or it will be stored as fat.
Carbohydrates, in the form of fruits, vegetables and grains, contain many useful vitamins, minerals, and antioxidants. The more refined the carbohydrate, the fewer natural nutrients are in the foods and must be added back in. Grains, widely used as fillers, are not as readily absorbed by a dog’s gut and most of it is expelled in the form of large smelly poops. In addition, it is the high percentage of grain in the dog’s diet that contributes to both diabetes and obesity.
When a dog is fed a large quantity of carbohydrate in a meal, it is absorbed into the system and becomes blood sugar (blood glucose). Excessive amounts of blood sugar causes the pancreas to excrete enough insulin to bring the blood sugar down to normal range. Insulin is a fat storage hormone. When there is too much blood sugar in the system, insulin shoves it into fat cells to get rid of it. Over time, if the carbohydrate content of the food is not reduced, and the dog does not get enough exercise to use the blood sugar in the system, the dog will become obese and may also become diabetic.
Feed lots feed cattle grain, especially corn, to “fatten up” cows for market. What works to fatten up cows also works for dogs.
Dog breeds that are prone to obesity are those who are either “pampered pets” or are deliberately fattened up for a dog show.