In addition to reducing an overweight pet's energy intake, by increasing energy expenditure through increased exercise, you
will increase weight loss.15,16 A maximally effective weight-management program incorporates both calorie restriction and exercise recommendations.
Interactive exercise between dogs and owners is an alternative activity to enhance the human-animal bond, and increased activity
could enhance weight loss in pets. Common examples of potentially appropriate exercises include low-impact walking, chasing
a ball, tossing a Frisbee, swimming or using an underwater treadmill, and socializing at a dog park. Guided-exercise treatments
with a certified canine rehabilitation practitioner following veterinary consultation may be beneficial in maximizing weight-loss
In obese dogs, it is important to start an exercise program slowly and gradually increase the duration and intensity of the
exercise. In some dogs, exercise may be impossible because of severe orthopedic or cardiopulmonary problems or because of
the owners' inability to exercise with their pet.
The parallel problem of excess weight in pets and their owners represents a unique opportunity to target weight loss and increase
activity in both groups. A comprehensive prospective study that is underway, Owners and Pets Exercising Together (OPET), uses
the dog-owner relationship to affect the physical activity of both owner and animal (see the Related Link "Owners and Pets Exercising Together study" below).17
Three pharmacologic approaches to weight management are available for people: drugs that reduce fat digestion from the intestine,
drugs that reduce appetite, and drugs that increase metabolism. Of these three types of drugs, only orlistat (Xenical—Genentech)
is approved for human consumption in the United States. Sibutramine (Meridia—Abbott Laboratories, Reductil—Abbott Laboratories)
was withdrawn from the U.S. market by the Food and Drug Administration in October 2010. Orlistat is a derivative of a lipostatin
that inhibits gastrointestinal lipases. In contrast to orlistat, sibutramine is a noradrenergic, serotonergic reuptake inhibitor
that enhances both satiety and thermogenesis.
Photo by Gregory Kindred
Only one weight-loss drug is approved for administration in dogs in the United States. Dirlotapide (Slentrol—Pfizer Animal
Health) is an intestinal microsomal triglyceride transfer protein inhibitor that prevents formation of chylomicrons in intestinal
cells. This action results in an increase in peptide YY secretion. Peptide YY is a potent appetite suppressant that affects
the satiety center in the hypothalamus and accounts for 90% of the drug action. The reduction of fat absorption in the small
intestine due to the prevention of chylomicron formation is responsible for only a small fraction of the effect, and, thus,
steatorrhea related to fat malabsorption is minimal.18-23
All pharmacologic weight-management aids should be considered short-term interventions, may have significant side effects,
and may be contraindicated in some patients. Additionally, weight loss achieved by patients will most likely be temporary
if owner behaviors are not concurrently modified to promote a more healthful lifestyle. For example, it is helpful to explain
to owners that treats are similar to snacking between meals for people, and when giving treats is a well-established habit,
it may require consciously and permanently adjusting what role treats play in the relationship (i.e. owners should consider bonding with their pets via a physical activity rather than through giving treats).