Obesity quiz

Obesity in dogs and cats: battling the buldge

SASKATOON, SK – To solve a medical problem like obesity you need a two-pronged approach: prevention and management. The obesity epidemic in the pet population in North America parallels the human obesity epidemic; an estimated 20% of the human population is obese, while 25-35% of adult cats and 35-40% of adult dogs are obese, explained Elisabeth Snead, BSc, DVM, MSc, Diplomate ACVIM, speaking at the Saskatchewan Association of Veterinary Technologists Conference. Spayed and neutered animals are at greatest risk, as are certain breeds and those with certain risk factors.

Obesity defined

Obesity is a disease in which there is an accumulation of excess body fat such that health may be adversely affected. In dogs and cats, the normal percentage of body fat is considered to be 15-20%. Overweight pets have 25-40% body fat, and obese more than 40% body fat.

It is theorized in humans that in addition to overeating and decreased exercise, which are the major contributing factors for obesity, other potential contributing factors for obesity include infectious agents, gut flora disturbances, hormonal disruptions from environmental contaminants, and psychological stress. Treatments for obesity include dietary management, exercise, psychological and behavioural modification, drug therapy, and surgery.

Dr. Snead said that it is important to prevent and/or control obesity because adipose tissue (body fat) produces a lot of pro-inflammatory adipocytokines. The upregulation of the systemic inflammatory response is linked to chronic diseases associated with obesity, such as heart disease, diabetes, interstitial cystitis, orthopedic diseases, and some cancers. As well, obesity causes organs to get compressed and puts extra strain on joints and ligaments. Scientific evidence also shows that obesity leads to shorter lifespan and greater disease morbidity; a landmark study involving Labrador retrievers demonstrated that lean control dogs lived 1.8 years longer than obese dogs.

Assessing body fat

DEXA evaluation, which uses low-beam x-rays to assess body fat mass, is currently considered the gold standard for determining body fat percentage.   Risk for morbidity associated with being overweight or obese is positively correlated with increasing body fat percentage.

Risk assessment Healthy weight Moderate risk High risk Serious risk Severe risk Extreme risk
% body fat 16-25% 26-35% 36-45% 46-55% 56-65% >65%

DEXA scans, however, are relatively expensive and not readily available.  A simpler method is the Body Condition Scoring (BCS), which is based on a five- or nine-point scale.  Body condition scoring tends to be more accurate than relying on what the ideal body weight should be based on a breed standard.  However, an important limitation with using BCS to help determine what the ideal body weight of a patient should be is that this system lacks discrimination over the whole range of obesity.

Obesity prevention

Prevention begins with accepting the fact that obesity is a major medical problem that can and does shorten a pet’s lifespan and can affect the affected pet’s quality of life. While some risk factors are unavoidable, such as genetics, age, and gender (male versus female), other risk factors can be prevented or modified. These include the amount of daily physical activity, reproductive status, the caloric density of food being fed, and the owners’ own perceptions about weight. Dr. Snead said that since spaying and neutering significantly decrease the caloric requirements to maintain normal body weight, nutrition counselling should be provided before such routine surgeries are performed, at a follow-up appointment to ensure the animal did not develop any post-operative complications, and then again at every appointment thereafter. Education about the importance of maintaining a healthy weight should be part of every wellness exam starting at puppy- and kitten-hood onwards.  Important topics to discuss include the amount and composition of the pet’s current diet and the importance of regular exercise. Finally, pet owners should be taught to detect weight changes early and understand the importance of obesity prevention.

Chart is courtesy of Hill’s Pet Nutrition Canada Inc.

Nutritional assessment

Every assessment should start with a baseline: the type and brand of food being fed; amount and type of treats/table food each day; feeding methods (free choice, meal times); history of medical conditions that impact or dictate the type of food being fed; obesity risk factors; and the pet’s appetite and eating habits. A record should be made of at least two out of three objective measures of the pet’s nutritional status, such as recording the body weight, BCS, and body fat mass index or morphometric measurements. The client should then receive a specific recommendation about what food should be fed, the amount to feed, and the preferred feeding method based on determination of what the patient’s ideal body weight should be. In some cases, blood work and other diagnostic tests may be indicated to fully assess the patient’s nutritional status and to rule out possible underlying contributing endocrine disorders.  Dr. Snead stressed that food-restricted meal feeding is the best strategy for weight loss and for preventing obesity, provided that portion sizes are appropriate.

Feeding plan

To prevent obesity, maintenance food is appropriate if the pet is at an ideal bodyweight. A food specific to the pet’s life stage should be used and not an all-purpose maintenance food that can be fed for the whole spectrum of life stages. For overweight but not obese pets, a “light” calorie restricted food is recommended. This is preferable to feeding less of a maintenance food since the latter could lead to nutritional inadequacies.  Obese pets should be on a weight loss diet that is lower in calories and fat, supplemented with protein and micronutrients, and generally also has increased fibre to promote satiety.

A simple tool to use to calculate the pet’s ideal bodyweight is available at www.HWP.HillsVet.ca. The tool creates a weight loss schedule designed to set weight loss expectations with the client, as well as a feeding plan to meet those expectations. Another method is to use a Body Fat Index chart designed with descriptors and images as a guide to evaluate the pet to determine their body fat index, and to establish the pet’s ideal body weight. Regardless of the tool used, stressed Dr. Snead, timely and continued follow-up is considered to be the single most important determinant of the success of any weight loss program. The aim should be to achieve weight loss of about 1-2% per week.

Encouraging and motivating clients

Helping clients locate resources, such as doggie day care and rehabilitation facilities, and recommending environmental enrichment, exercise options, and novel feeding strategies for their pets, will help motivate clients to keep their pets at a healthy weight. Encouraging them to exercise with their pet, by slowly building up stamina if necessary, and making sure exercise occurs during cool times of day, especially for obese pets, is a great way to improve client-pet interaction and exercise levels. As well, it is important to educate clients on the importance of limiting treats and avoiding table scraps and restricting food to regular mealtimes.


The focus of obesity management and prevention should be on determining accurate calorie requirements and realistic increases in physical activity.  Morphometric measurements and Body Fat Index are recommended tools to allow a more precise determination of the ideal body weight for an overweight pet, and regular re-checks are essential. Finally, clients should be encouraged to keep their pets active and stimulated.CVT