Gonadectomy in dogs also results in modified feeding patterns.

Neutering results in the net loss of circulating sex hormones, slowing an animal's metabolism and predisposing the neutered animal to becoming overweight or obese.14,15,28 Changes in sex hormones after neutering directly affect the satiety center in the brain through changes in leptin and ghrelin concentrations and possibly indirectly affect it by altering cell metabolism and hormonal regulators of food.24,29-31 In short, a reduced metabolic rate associated with aging predisposes dogs to being overweight or obese.27 If food intake does not decrease proportionately with the decreasing energy needs, weight gain results.26 The end result is an increasing prevalence of obesity in older dogs. The total daily energy needs of an average-sized 7-year-old dog may decrease by as much as 20% when compared with its needs as a young adult. Recent data in various animal species provide new insight into the genetic basis of obesity.19-21 A significant breed predisposition to obesity has been shown in certain breeds including Cairn terriers, West Highland white terriers, Scottish terriers, Shetland sheepdogs, basset hounds, Cavalier King Charles spaniels, dachshunds, beagles, cocker spaniels, and Labrador retrievers.12,15,22-24 Conversely, certain breeds, particularly sight hounds, appear to be resistant to the development of obesity.24Īs an adult animal ages, lean body mass declines, resulting in a decrease in total daily energy needs.25 The loss of lean body mass is exacerbated if aging is accompanied by a decrease in voluntary activity. Studies from throughout the world have estimated the prevalence of overweight or obese dogs to range between 22% and 40%.13-17 Cross-sectional data suggest one in three dogs seen by U.S. Obesity is one of the most important medical problems in dogs.

In most animals, obesity results from an imbalance between energy intake and energy expenditure.

Underweight (BMI 15% above ideal and are obese when their weight is > 30% of ideal.11,12 However, these criteria have not been confirmed with rigorous epidemiologic studies, and limited data exist on the definition of an optimal body weight.

Obesity is defined as excessive white adipose tissue.1 Human epidemiologic data show increased morbidity and mortality with increasing body fat mass.2 The most commonly used measure of body fat in people is the body mass index (BMI: weight divided by height2 ). In Part 2, we discuss treatment and monitoring strategies.

In Part 1 of this two-part series, we explore common causes of weight gain in dogs and the consequences of dogs being overweight or obese. Excess weight is the most common medical condition in companion animals and has a number of health and wellness implications for both pets and their owners.Ĭertain behaviors predispose dogs to weight gain. It is generally accepted that the prevalence of overweight and obese pets has increased in recent years.

Dog obese