Obesity and overweight are common conditions in dogs, especially in industrialized countries where food availability is not a problem.

Obesity may be primary in origin, resulting from overall higher calorie intake than calorie expenditure, or more rarely it may be secondary to certain endocrinopathies such as hypothyroidism, hyperadrenocorticism or insulinomas.

The major causes of primary obesity in dogs include dietary errors, such as feeding energy-dense, nutrient-poor diets, and low physical activity. Predisposing factors are age (greater than 7 years), sex (female), reproductive status (surgical sterilization or castration), and race (Labrador, Cairn Terrier, Basset Hound, Shetland Sheepdog, Cocker Spaniel, Beagle, King Charles Spaniel).

As in human medicine, the cornerstone of obesity treatment in dogs is lifestyle modification, which involves implementing dietary and exercise changes.

Since the goal of weight loss is to reduce the body fat content while maintaining other body tissues and metabolism, diet should be low in calories only, not in essential nutrients such as amino acids, vitamins and trace minerals. That’s why short-term starvation and feeding less amounts of the normal diet are highly contraindicated methods to restrict calorie intake.

The best and more appropriate solution to restrict calorie intake is to feed overweight dogs a properly formulated weight loss diet, specifically designed to be low in calories with increased concentrations of all other essential nutrients. There are many commercially available weight loss pet foods, some of them containing insoluble fiber (on average 10% to 15% of the dry matter) that helps dilute diet calories, increase satiety, and limit food consumption by increasing digested bulk and prolonged distension of the gastrointestinal tract. It is advisable to feed fewer or no treats, table foods or snacks because these foods are usually high in calories, while they do not affect the daily nutrient intake balance. Another strategy is to change treats to high-water (squashes) or fibrous (broccoli) vegetables, because they contain no calories to be counted.

It is important to stress that over-the-counter pet food products labeled “light”, “lite” or “reduced calorie or fat” are formulated for weight maintenance, not for weight reduction. Although some properly formulated over-the-counter “reduced calorie” diets may be fed at 25% less than the recommended feeding in order to achieve moderate weight loss, this method is not advisable as a general rule.
not advisable as a general rule.

The new diet should be introduced gradually over a 6-10 day period and daily dietary ration should be divided in several small portions, in order to reduce the feeling of hunger. The daily caloric intake for weight loss should be 40% to 60% of the maintenance energy requirements at the target or optimal body weight. With such a calorie restriction, weight loss is 1-2% of body weight per week if your dog is fat.

The weight loss plan should also include an increase of physical activity (e.g., walking 30-60 minutes a day) and, when necessary, the dietary supplementation with chromium, which supports glucose and fat metabolism, L-carnitin, which helps burn fats for energy, and vitamin A, which plays a key role in lowering leptin levels, thereby reducing food intake and increasing energy expenditure.