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Veterinarian Technician January 2008 (Vol 29, No 1)

Managing Obesity in Dogs and Cats

by Dana Call, RVT, VTS, (ECC)

    CETEST This course is approved for 0.5 CE credits

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    Although numerous factors may contribute to the development of obesity in pets, overfeeding and underexercising are the two most significant causes.1 With the proper weight loss program, obesity can be successfully treated. Client compliance is also essential to the program's success. See Glossary .

    Patient Assessment

    Patient History

    Obtaining a thorough patient history is the first step in evaluating the nutrition status of a pet. The history should include signalment (i.e., species, breed, age, weight, sex, reproductive status), activity level (i.e., active or sedentary), and environmental factors (e.g., only pet in household, fed by one person or numerous individuals). For patients that are above optimal weight, the information obtained from the history may help to indicate if the weight gain is related to a medical condition. For example, conditions such as ascites, edema, hyperadrenocorticism, and heart disease may cause weight gain, increased girth, or exercise intolerance.1 To detect weight problems early, each patient should be weighed during every office visit and the weight should be recorded in the patient's medical record.

    Diet History

    In addition to obtaining a patient history, it is essential that the technician obtain a diet history. A thorough diet history can help determine exactly what the pet is being fed and what factors should be considered when creating a weight loss plan. If possible, owners should be given a diet history form to fill out before the visit. By filling out the form at home, the owner will be more likely to remember to list all foods, including table scraps and treats, that he or she gives the pet.

    The diet history form should include questions about the type of food being fed as well as the quantity and frequency (e.g., whether the pet is fed only at mealtimes or is fed free choice). The client should indicate the exact amount of food, in standard (8-oz) cups, that is being fed to the pet. The technician should make sure that the owner is correctly measuring commercial dry food in 8-oz cups. Many owners do not know how much food their measuring scoop holds. It is also important to question the owner about supplements, foods that are fed with medications, table scraps, and treats. In addition, the form should indicate whether the pet is being fed a nutritionally balanced homemade diet, and if so, what ingredients are being used and in what quantity.

    Physical Examination

    Before creating a weight loss program, a complete physical examination should be performed to determine the patient's health status. A complete blood count, serum chemistry profile, thyroid hormone panel, and urinalysis may be ordered to help the veterinarian rule out a medical condition as the cause of the weight gain.

    Following the physical examination, the pet's body condition score (BCS) should be determined. BCS is a semiquantitative method used to determine whether a patient is at optimal weight or is underweight, overweight, or obese. It involves visually assessing the patient's body condition and physically palpating the patient's ribs. Palpating the patient will ensure that the assessment is accurate, especially if the pet has a long or thick haircoat. The five-point scalea and the nine-point scale are the two most commonly used BCS systems.2,3 When using the five-point scale, 1/5 indicates that the patient is emaciated, 3/5 is ideal, and 5/5 is grossly obese.2 When scoring a patient using the nine-point scale, 1/9 is emaciated, 5/9 is ideal, and 9/9 is grossly obese.2 Although either scoring system can be used, the practice should select one system so that the patient is evaluated consistently every time.

    Another method of estimating body fat is to obtain the patient's morphometric measurements.b For this method, a measuring tape (graduated in centimeters) is used to measure different parts of the animal's body.3 There are two sets of measuring points: one for cats and one for dogs. Once the measurements are obtained, an equation is used to convert the morphometric measurements into estimates of percent body fat.3 BCS is often preferred over this method because morphometry requires complex calculations and numerous measurements that can be difficult to obtain.

    Before creating a weight loss program, the pet's relative body weight (RBW) should be determined. To obtain RBW, the patient's current body weight is divided by its optimal body weight.3 Animals that have a RBW of 1.00 or 100% are considered to be at their optimal weight.3 A RBW of less than 1.00 indicates that the patient's weight is less than optimal.3 RBW values of 1.10 and 1.20 indicate that the patient falls into the overweight or obese category, respectively.3 Several sources can be used to help estimate a patient's optimal body weight. The best method of obtaining optimal weight is to check the patient's medical record and locate a recorded adult weight and BCS that were obtained when the animal was classified as being at optimal weight.3 If a BCS is unavailable but the patient's weight is indicated in the file, then a close estimate would be the patient's weight at the time it reached adult age.3 Most cats and small-to-medium-breed dogs reach optimal body weight when they are a year old. If a dog's weight history is unavailable, the American Kennel Club has weight listings that are categorized by breed and sex.3 However, the American Kennel Club only provides information about purebred dogs, not mixed breeds. Once the patient's optimal weight has been established, a weight loss program can be created.

    Creating A Weight Loss Program

    After it has been determined that a pet is overweight or obese, treatment options, including changes in diet and physical activity, should be discussed with the client. Any medical conditions and deficiencies noted during exercise must be considered when developing a weight loss protocol. It is important to keep in mind that changes in diet to achieve weight loss may be an additional challenge in animals with medical conditions (e.g., diabetes mellitus, renal compromise).

    Nutritional Requirements and Intake Adjustments

    Dietary therapy is the foundation of weight management in companion animals.4 Dogs and cats are believed to require more than 50 nutrients to maintain good health and quality of life5; therefore, an animal's intake of essential nutrients should be considered when creating a weight loss program.

    Weight gain and obesity result when the animal's daily consumption of calories exceeds its daily energy expenditure over time.3 Therefore, a patient's energy requirement should be determined before initiating any changes in food intake. Energy requirement can be calculated using one of several methods. The box explains how to properly calculate metabolizable energy requirement.

    Once the animal's energy requirement is established, the number of calories being consumed should be compared with the number of calories needed for weight loss. The calorie content of all food, including treats, should be determined.3 Feeding a nutritionally balanced diet that provides 60% to 70% of the calories necessary to maintain current body weight usually results in adequate weight loss.1 After the veterinarian assesses the patient's blood work and physical examination findings, he or she will be better able to determine if the patient's current commercial diet is adequate or if the patient would benefit from a prescription weight loss diet.

    In cats, calorie restrictions should be conservative so that the cat is not fed less than 60% of its daily energy requirement at the start of the dietary adjustment.6 Technicians must tell cat owners to make sure that their cat continues to eat while the dietary changes are being implemented. Some cats may develop anorexia because of stress or attempts to change their food type.6 Because of the risk of hepatic lipidosis, cats cannot go longer than 48 hours without food.

    Physical Activity

    Weight loss programs that rely on calorie reduction alone may fail to help the patient lose weight. Exercise is the best method of ensuring that the energy expended is greater than the number of calories consumed.3 Overestimation of energy requirement based on current body weight and relatively low levels of daily exercise may stifle weight loss. Slowly introducing physical activity during weight loss has many benefits, including regulating food intake and building muscle (lean tissue). Because exercise requires energy, dietary restriction combined with exercise forces the body to use fat stores for energy.3

    For pets that are sedentary, the duration and intensity of exercise should slowly be increased as endurance improves. The owner should set a goal of 20 minutes of exercise 3 to 5 times a week.1 The exercise program should be determined by the physical capabilities and health of the pet and should be deemed safe and tolerable.3,6 Swimming can sometimes be advantageous for pets with osteoarthritis or cardiopulmonary disease. More calories per minute can be burned by swimming than by walking; therefore, the same number of calories can be expended in less time.3

    Increasing a cat's level of physical activity is challenging. Some cats can be trained to walk on a leash, although indoor cats may be reluctant to do so. Providing motorized play units and "fishing rod" toys may encourage a cat to play. In addition, offering feeding toys or placing the pet's food bowl in different areas of the house may entice the cat to move around.4 Use of play rewards may lead the pet to initiate play and exercise interactions.

    Implementing a Weight Loss Program

    Weight reduction protocols should be tailored to the individual patient. Slow transitions may yield greater long-term benefits. To help decrease begging, the technician can suggest that the owner offer more frequent meals while reducing overall daily food intake.7 Another way to discourage begging is to encourage the owner to keep the pet out of the kitchen while meals are being prepared and eaten.1 The technician can also suggest alternatives to table scraps or high-calorie treats. Air-popped popcorn, unflavored rice cakes, baby carrots,7 or cereals such as Cheerios or shredded wheat squares are possible substitutes.c

    While the pet is participating in the weight loss program, the owner should be encouraged to keep a food diary that details every food item, including treats and table scraps, consumed by the pet. Low-calorie treats can be given as long as they do not exceed 10% of the pet's total caloric intake.8

    Owner compliance is essential to weight loss in a pet. Therefore, technicians should counsel clients about the numerous health benefits that their pet will receive by losing excess weight. Some of the benefits include increased longevity,9 maintenance of body condition, reduced risk of musculoskeletal disorders, and improved glucose tolerance.4

    The veterinarian should review the diet plan with the owners. The technician can then provide a BCS chart, a measuring cup, an exercise plan, and nutritional information on diets and treats. To monitor progress, staff members should encourage the owner to bring the pet to the clinic for monthly assessments.8 Monitoring the patient's progress is essential and requires staff involvement.

    Patient Monitoring

    A weight loss goal of 1% to 2% of body weight per week is recommended for most pets. A balance between effective gradual weight loss and minimal loss of lean body tissue is optimal. Owners should be informed that weight loss in pets requires a lifelong commitment. It may take several months for a pet to lose weight. If weight loss is not evident during regular assessments, modifications in diet and exercise may be required. Slight reductions in body weight or BCS represent success; therefore, the owner should be congratulated for complying with the program.10


    Implementing a weight loss program in the clinic can improve patient care and longevity. Technicians can encourage compliance by sharing obesity prevention strategies with clients and recommend methods to reduce food intake as pets reach maturity and are neutered or spayed.3 They should also weigh patients at every visit and assess BCS. Owners who understand the importance of keeping their pet's weight at an optimal level can work with the staff to keep their pet healthy.

    1. Case LP, Carey DP, Hirakawa DA, Daristotle L: Obesity, in Canine and Feline Nutrition: A Resource for Companion Animal Professionals, ed 2. St. Louis, Mosby, 2000, pp 303-330.

    2. Remillard RL: Obesity: A disease to be recognized and managed, in Ettinger SJ, Feldman EC (eds): Textbook of Veterinary Internal Medicine, vol 1. St. Louis, Elsevier-Saunders, 2000, pp 76-78.

    3. Burkholder WJ, Toll PW: Obesity, in Hand MS, Thatcher CD, Remillard RL, Roudebush P (eds): Small Animal Clinical Nutrition, ed 4. Topeka, KS, Mark Morris Institute, 2000, pp 401-430.

    4. German AJ: The growing problem of obesity in dogs and cats. J Nutr 136(7 Suppl):1940S-1946S, 2006.

    5. Campbell KL, Corbin JE, Campbell JR: Companion Animals: Their Biology, Care, Health, and Management. Upper Saddle River, NJ, Prentice Hall, 2005, pp 168-211.

    6. Wills JM, Simpson KW (eds): The Waltham Book of Clinical Nutrition of the Dog and Cat, ed 1. Boston, Butterworth-Heinemann, 1994, pp 131-145.

    7. Kaplan H, Gurven M: The Natural History of Human Food Sharing and Cooperation: A Review and a New Multi-Individual Approach to the Negotiation of Norms. Preliminary Draft. Prepared for the Conference on the Structure and Evolution of Strong Reciprocity, Santa Fe Institute, Santa Fe, NM, March 9-11, 2001; cited with permission (Gurven M).

    8. Yaissle JE, Holloway C, Buffington CA: Evaluation of owner education as a component of obesity treatment programs for dogs. JAVMA 224(12):1932-1935, 2004.

    9. Kealy RD, Lawler DF, Ballam JM, et al: Effects of diet restriction on life span and age-related changes in dogs. JAVMA 220(9):1315-1320, 2002.

    10. Delaney SJ: Identify At-Risk Patients When Battling Obesity in Companion Animals. Accessed December 2007 at www.dvmnews.com/dvm/DVM+InFocus/Identify-at-risk-patients-when-battling-obesity-in/ArticleStandard/Article/detail/162668.120.

    aTo download a BCS chart using the five-point scale, check out this month's Web Exclusive .

    bFor more information about morphometric measurements, see Burkholder WJ, Toll PW: Obesity, in Hand MS, Thatcher CD, Remillard RL, Roudebush P (eds): Small Animal Clinical Nutrition, ed 4. Topeka, KS, Mark Morris Institute, 2000, pp 401"430.

    cA Heintz, DVM; J Lee, DVM: Personal communication, Wedgewood Pet Clinic, Oklahoma City, Oklahoma, 2007.

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    Did you know... For dogs with protein-losing nephropathy, protein restriction is recommended even in early stages of the disease.Read More

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