Battling the Bulge
Healthy diet advice for overweight dogs
Recent surveys suggest that 25 to 40 percent of dogs visiting veterinary clinics are overweight or even obese. Although dog competitors may have a lower level of weight problems compared to the average pet owner, even seasoned breeders often have a dog or two they can’t seem to get the weight off of.
Certain breeds—such as Labrador Retrievers, Golden Retrievers, Beagles, Dachshunds, Cocker Spaniels, Collies, Cairn Terriers, Cavalier King Charles Spaniels, Shetland Sheepdogs, and Basset Hounds—seem to be more prone to obesity, suggesting a genetic aspect to weight gain. Spaying or neutering has been assumed to lead to increased chance of obesity: A relationship has been demonstrated in cats, but so far no definitive study is available for dogs. Some owners blame obesity on endocrine problems such as hypothyroidism, but in reality, probably less than 5 percent of obesity cases are caused by any kind of disease or drugs.
As in humans, obesity has serious health implications. It’s associated with increased incidence of arthritis, diabetes mellitus, cardiovascular problems, urinary incontinence in spayed bitches, dermatitis, and increased surgery and anesthesia risk, among other problems. Even longevity is reduced with obesity: A well-known study that paired free-fed Labrador Retrievers with littermates allowed to eat only 75 percent of what the free-fed dogs ate showed that the free-fed dogs lived on average two years less than the restricted dogs.
It seems it should be easy to diet a dog. And in fact, for kennel dogs, it is. Simply provide less food and don’t look into their pleading eyes. And even for house dogs, just don’t let them do the grocery shopping or take trips to fast-food places. But for most house pets, it’s not that easy. Most owners find that feeding their dog is a bonding experience, and they derive pleasure from seeing their dogs enjoy a tasty meal or special treat. They find it uncomfortable to ignore begging behavior, and tend to add a little more or give a handout “just this once.” Nonetheless, you can help your dog lose weight without being an ogre about it. And no, liposuction and bypass surgeries are not an option. Losing weight mainly depends on consuming fewer calories than are expended, which means controlling diet and exercise, and maybe drugs.
Simply feeding less of the current diet is not the optimal solution for a couple of reasons. First, your dog is going to be hungry because he’s not getting as much food as he’s used to. Second, by feeding less you’re also feeding fewer vital nutrients. Feeding a lower-than-normal amount of an average maintenance diet can lead to deficiencies in protein, vitamins, minerals, and essential fatty acids. The same is true when supplementing with large volumes of low-calorie fillers, such as the often-suggested can of green beans. It may be a short-term method to get weight off while filling the dog’s stomach, but long-term, it may lead to nutritional deficiencies. Also note that green beans directly from the can are often extremely high in salt, which may be bad for some dogs.
Most canine nutritionists advocate feeding low-calorie diets designed for weight loss rather than feeding less of the dog’s normal diet. These diets are usually low in fat, high in protein, and high in micronutrients. They have increased levels of essential fatty acids, vitamins, and minerals relative to calories to avoid nutritional deficiencies when dieting.
High protein is important because it minimizes the amount of the dog’s own lean tissue metabolized when the energy ingested falls below energy expended. Many weight-loss diets are supplemented with L-carnitine, which has been shown to cause preferential loss of fat over lean tissue during weight loss. Some diets also contain conjugated linoleic acid, which may limit the production of long-chain fatty acids.
Increasing levels of dietary fiber is often promoted to bulk the food up and thus increase satiety. This would seem to make sense, but several studies have found the addition of either soluble or insoluble fiber, at moderate or high levels, has no effect on satiety or feeding behavior in dogs. In fact, certain negative aspects are associated with high fiber levels, such as poor palatability, poor compliance with dogs eating the food, reduced nutrient availability, and increased stool volume. When dogs don’t want to eat these foods, owners are more likely to give in and abandon the diet. The question of whether high fiber levels are beneficial in weight-loss foods is still controversial, so you’ll see diet foods with both increased and normal fiber levels on the market.
When dieting your dog, follow these steps:
- Have a veterinary examination to eliminate medical causes of obesity (or its appearance), such as endocrine disorders or ascites from heart disease.
- Set a target weight that should be at least 85 percent of initial body weight.
- Calculate the calories to be fed per day as “= 55 x [initial body weight (kg)0.75]”
- Feed a low-calorie, high-protein food with increased levels of micronutrients. Note that calories per cup of even diet dog foods can vary greatly, so compare calories.
- Determine how many calories are in a cup of your chosen food, and determine the amount to be fed accordingly.
- Weigh the dog weekly and graph results. Report the results to a third party, which tends to increase owner compliance.
- Dieting your dog is challenging, but even without reaching a Baywatch figure, your dog’s quality of life can be improved. The trick may require reaching a compromise between the quality (and length) of life afforded by a healthier weight with the quality of life afforded by a satisfying meal.
Doggy Diet Pills
As with humans, various diet pills have been evaluated for their ability to decrease appetite or caloric absorption. These include herbal products containing guarana and ma huang, as well as other products commonly tried in humans. Only the drug dirlotapide, which was developed specifically for dogs, has been shown to be safe and effective. Dirlotapide acts by inhibiting an intestinal enzyme (MTP, or microsomal triglyceride transfer protein), which normally aids in the absorption of fats in the intestinal cells. As the ingested but unabsorbed fat accumulates in the intestinal cell, it triggers a hormonal response that signals the brain to stop eating. In other words, it tricks the brain into feeling the dog is full after a smaller meal. The dog eats his normal maintenance food, although you must make sure he eats enough to obtain adequate levels of protein and other nutrients.
A high-quality commercial diet is recommended, and home diets are not recommended because of the possibility of inadequate intake of some nutrients, especially the fat-soluble vitamins A, E, and K. Dosing is calibrated so that the dog optimally loses about 3 percent of his body weight a month. After the target weight is reached, the dog is maintained on dirlotapide for another three months. Once the drug is discontinued, the dog’s appetite will return, and there’s a potential for weight gain unless the dog’s diet and exercise are controlled. Side effects, if any, tend to be mild but can include vomiting, diarrhea, and lethargy. Dirlotapide is not recommended for dogs with liver disease, Cushing’s disease, or those receiving corticosteroids, or for growing, pregnant, or nursing dogs.
- Metabolizing food takes energy, and eating several small meals a day uses more energy than eating a single large meal.
- Feed low-calorie snacks such as carrots, other vegetables, fruit, rice, or even ice cubes. Include treats in the daily allotted calories, and limit treats to less than 10 percent of daily caloric intake.
- Make sure everyone in the family follows the diet rules.
- Remove the dog from food-preparation areas or from rooms where people are eating, both of which tend to increase the tendency to beg and to receive tidbits.
- Exercise also plays a role in weight loss, but it must be tailored to the dog’s body state. For obese dogs, suitable low-impact exercise includes leash walking, swimming, treadmills, and underwater treadmills.
Prevent obesity by not overfeeding puppies, which increases the number of fat cells throughout life.
First published in the February 2011 AKC Gazette. To subscribe to the Gazette, please go to www.akc.org/pubs/index.cfm.
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