Management of obesity in cats

Kirsten M Hoelmkjaer, Charlotte R Bjornvad Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark Abstract: Obesity is a common nutritional disorder in cats, especially when they are neutered and middle-aged. Obesity predisposes cats to several metabolic and clinical disorders, including insulin resistance, diabetes mellitus, lameness, and skin disease. Prevention and treatment of obesity is therefore of great importance in veterinary practice. Correct assessment of body composition is important for recognizing early states of obesity and for monitoring success of weight-loss programs. Various methods for assessing body composition have been proposed, of which a 9-point body-condition score has been validated in cats, and is possibly the most simple to use in the clinic; however, for extremely obese individuals, it is less useful. When calculating the appropriate daily caloric intake for a weight-loss plan, the aim is to maintain a safe weight-loss rate, increasing the chance of preserving lean body mass and decreasing the risk of developing hepatic lipidosis, while also producing a sufficient weight-loss rate to keep owners motivated. A weight-loss rate of 0.5%–2% per week is recommended, which for a cat that needs to lose 3 kg body weight results in an anticipated time for reaching the target weight of 24–60 weeks. There are several purpose-made weight-loss diets available. The optimal composition of a weight-loss diet for cats is unknown, but most of the available products have lower caloric density, an increased nutrient:energy ratio, and higher protein and fiber content. Regular follow-up visits allow the caloric intake to be adjusted based on progress, and possibly increase the chance of success. This review discusses the risk factors for and consequences of obesity, and gives directions for formulating a weight-loss plan, including daily caloric intake, choice of diet, and common problems based on the current literature. This review further provides a nutritional comparison of the current composition of selected commercial veterinary-specific weight-loss diets. Keywords: body condition, glucose intolerance, veterinary weight-loss diets, weight-loss managemen

Obesity‐induced changes in gene expression in feline adipose and skeletal muscle tissue

Indoor-confined cats are prone to developing obesity due to a sedentary life and an energy intake exceeding energy requirements. As in humans, feline obesity decreases insulin sensitivity and increases the risk of developing feline diabetes mellitus, but the pathophysiological mechanisms are currently poorly understood. Human obesity-related metabolic alterations seem to relate to changes in the expression of genes involved in glucose metabolism, insulin action and inflammation. The objective of the current study was to investigate changes in the expression of genes relating to obesity, glucose metabolism and inflammation in cats with non-experimentally induced obesity. Biopsies from the sartorius muscle and subcutaneous adipose tissue were obtained from 73 healthy, neutered, indoor-confined domestic shorthaired cats ranging from lean to obese. Quantification of obesity-related gene expression levels relative to glyceraldehyde-3-phosphate dehydrogenase was performed by quantitative real-time polymerase chain reaction. A negative association between obesity and adiponectin expression was observed in the adipose tissue (mean ± SD; normal weight, 27.30 × 10-3 ± 77.14 × 10-3 ; overweight, 2.89 × 10-3 ± 0.38 × 10-3 and obese, 2.93 × 10-3 ± 4.20 × 10-3 , p < 0.05). In muscle, the expression of peroxisome proliferative activated receptor-γ2 and plasminogen activator inhibitor-1 was increased in the obese compared to the normal-weight cats, and resistin was increased in the normal-weight compared to the overweight cats. There were no detectable obesity-related changes in the messenger RNA levels of inflammatory cytokines. In conclusion, a possible obesity-related low-grade inflammation caused by increased expression of key proinflammatory regulators was not observed. This could imply that the development of feline obesity and ensuing insulin resistance may not be based on tissue-derived inflammation, but caused by several determining factors, many of which still need further investigation