Canine Obesity Research Articles

An epidemiological study of environmental factors associated with canine obesity

To assess the relationships between socioeconomic and other environmental factors with canine obesity. This was a cross-sectional questionnaire study of dog owners attending five primary veterinary practices in the UK. Owners were asked about dog age, neuter status, feeding habits, dog exercise, household income and owner age. The body condition score of the dogs was also assessed. Factors hypothesised to be associated with obesity were investigated. In total, data from 696 questionnaires were evaluated. Out of those data evaluated, 35.3% of dogs (n=246) were classed as an ideal body shape, 38.9% (n=271) were overweight, 20.4% (n=142) were obese and 5.3% (n=37) were underweight. Identified risk factors associated with obesity included owner age, hours of weekly exercise, frequency of snacks/treats and personal income. Environmental risk factors associated with canine obesity are multifactorial and include personal income, owner age, frequency of snacks/treats and amount of exercise the dog receives. Awareness about health risks associated with obesity in dogs is significantly less in people in lower income brackets. This phenomenon is recognised in human obesity.

A review of osteoarthritis and obesity: current understanding of the relationship and benefit of obesity treatment and prevention in the dog

Obesity is an increasingly important health problem for both man and dog. Osteoarthritis (OA) is a significant cause of pain and disability in both species. A link between obesity and OA has been established in man, though the exact mechanism of the relationship remains to be fully elucidated - current research supports both biomechanical and biochemical theories. There is good evidence (class I*) to support weight loss as an effective treatment for human knee OA. In the dog, the relationship is just beginning to be investigated. The results of one study in dogs (class IV evidence*) suggest that preventing the development of overweightness and obesity reduces the prevalence of hip dysplasia and OA of the hip and other joints. Three other studies (class III and IV evidence*) support weight loss as an effective treatment for OA in affected overweight and obese dogs. Further research could yield greater understanding of the pathophysiology of this relationship, perhaps identifying novel therapeutic targets. Confirmation and better understanding of the positive effect of treating and preventing obesity on symptoms and prevalence of OA is likely to be valuable in the campaign against canine obesity.

Update on the management of canine obesity

This article provides an overview of the management of canine obesity, with particular reference to the recent introduction of anti-obesity drugs and their role in weight management programmes. Obesity is best defined as an accumulation of excessive amounts of adipose tissue in the body. The term obese should be reserved for those cases whose current weight is 30% above their ideal (animals are termed overweight if they are 15 to 30% above their ideal). In most animals, obesity is the result of a simple imbalance between energy intake and energy expenditure. Numerous factors may influence the relative ease with which weight is gained, and these include genetics, age, neuter status, amount of physical activity, and the caloric content of the diet. In comparison with ‘simple’ obesity, medical causes such as hypothyroidism and hyperadrenocorticism, are comparatively rare (typically <1% of the overweight dog population), but should be considered when other clinical signs compatible with these conditions are also present. The most recent studies in Australia, France, USA and the UK estimate the prevalence of overweight dogs at 29-37% of the pet dog population, whilst 5-15% are judged to be obese. Most investigators agree that, as in humans, the incidence of obesity in the pet population is increasing. It is likely that dogs which are obese are more likely to be at increased risk of a variety of associated diseases such as diabetes mellitus, certain cancers and arthritis as well as having a reduced overall longevity. Recently a prospective study has demonstrated that a group of Labradors fed ad libitum had a shorter median life span (11.2 years) than a paired group (13 years) each member of which was fed 75% of the amount consumed by the respective pair. Other beneficial effects in the diet restricted group included reduced risk of orthopaedic disorders such as osteoarthritis and hip dysplasia, and improved glucose tolerance.

Effects of green tea on insulin sensitivity, lipid profile and expression of PPARα and PPARγ and their target genes in obese dogs

As in man, canine obesity is associated with insulin resistance, dyslipidaemia and other chronic diseases. This study was designed to examine the effects of a nutritional supplement (green tea) on insulin sensitivity and plasma lipid concentrations in an obese insulin-resistant dog model. We also determined mRNA expression of two transcription factors, PPARgamma and PPARalpha, and some of their target genes, including GLUT4, lipoprotein lipase (LPL) and adiponectin. Obese dogs were divided into two groups: a green tea group (n 6); a control group (n 4). Dogs in the green tea group were given green tea extract (80 mg/kg per d) orally, just before their single daily meal, for 12 weeks. Insulin sensitivity (using a euglycaemic-hyperinsulinaemic clamp) and concentrations of plasma TAG, total cholesterol and NEFA were assessed in each group. Gene expression was measured in visceral and subcutaneous adipose tissues and in liver and skeletal muscle, by real-time PCR. At 12 weeks in the green tea group, mean insulin sensitivity index was 60 (SEM 11) % higher (P < 0.05) and TAG concentration 50 (SEM 10) % lower (P < 0.001), than baseline. PPARgamma, GLUT4, LPL and adiponectin expression were significantly higher in both adipose tissues, whilst PPARalpha and LPL expression were significantly higher in skeletal muscle, compared with baseline. These findings show that nutritional doses of green tea extract may improve insulin sensitivity and lipid profile and alter the expression of genes involved in glucose and lipid homeostasis.

Relationship between analytic values and canine obesity

The objective of this study was to assess the relationship between canine body condition and metabolic parameters like serum lipids, blood glucose and alanine aminotransferase (ALT) concentrations. We selected 127 dogs (42 males and 85 females) that were taken to our veterinary medicine service during routine visits. The mean age was 6.67 +/- 5.24 years. Body condition (BC) was measured by Laflamme scale and dogs were considered as obese when BC score was over 6. The following variables were collected: total cholesterol, high-density lipoprotein cholesterol, triglycerides, basal glucose and ALT. 66.1% of the dog cohort were obese. Total cholesterol and triglycerides were found to be higher (p < 0.05) in obese dogs with respect to normal weight dogs. In conclusion, obesity in dogs is associated with higher serum lipid levels.

Association of canine obesity with reduced serum levels of C-reactive protein

The prevalence of obesity is increasing in dogs as well as in humans. C-reactive protein (CRP) is an important tool for the detection of inflammation and/or early tissue damage and is linked to obesity in humans. The objective of the present study was to determine if serum CRP levels are altered in obese dogs. Fifteen lean (control group) and 16 overweight (obese group) dogs were examined. Blood samples were collected under fasted conditions for serum determination of CRP, glucose, insulin, cholesterol, triglyceride, and fructosamine. Results indicated that obese dogs were insulin resistant because serum insulin and insulin/glucose ratios were higher than in lean dogs (P < or = 0.05). Serum CRP concentrations were lower in obese dogs than in controls (P < or = 0.001). C-reactive protein was negatively correlated with insulin/glucose ratio (R = -0.42) and cholesterol (R = -0.39; P < or = 0.05). Furthermore, levels of cholesterol, triglycerides, and fructosamine were increased in the obese group compared with the control group. Based on these results, it can be postulated that CRP production is inhibited by obesity and insulin resistance in dogs.

Abdominal Obesity: Role in the Pathophysiology of Metabolic Disease and Cardiovascular Risk

Visceral adiposity has been identified as an independent risk factor for cardiovascular disease and the so-called metabolic syndrome. The canine obesity model closely recapitulates the correlation between human visceral adiposity and insulin resistance. A recent canine study indicates that insulin expands the volume of distribution associated with skeletal muscle, and that its ability to enhance macromolecular distribution within this space is blunted in the fat-fed obese canine model. Our canine study supports the portal theory of insulin resistance, in which free fatty acids (FFAs) from visceral fat directly enter the liver and have a detrimental effect on insulin action. The role of adipokines in this condition remains less clear. Sympathetic nervous system hyperactivity in obesity may also contribute to excessive FFA release, hypertension, and insulin resistance. Pathologies interrelated with insulin resistance include β-cell hypersecretion, reduced insulin clearance, and resultant hyperinsulinemia. An observed nocturnal increase in plasma FFA levels may account for both insulin resistance and compensatory hyperinsulinemia and warrants further investigation. The elucidation of these interrelated pathologies may help reveal points where medical intervention can reduce metabolic disease.

A weight loss protocol and owners participation in the treatment of canine obesity

The success of a weight loss program for pets depends on the owners collaboration. Their compliance is fundamental in establishing the correct food management. The objective of this study was to compare the effectiveness of a weight loss program in two groups of dogs, one maintained under experimental conditions and the other with their owners. The same hypocaloric food was used to feed all animals, the amount being restricted to 60% of the estimated maintenance energy requirement for a 15% reduction of the present body weight of the dog. The animals were followed during 90 days. A standard questionnaire was used to study the owners' perception of obesity and its treatment. The protocol and the diet were found to be effective. The control dogs had an average weight loss of 1.39% per week. Dogs with owners lost on average 0.75% of their body weight per week, a statistically lower result (P&lt;0.05), suggesting that the owners did not follow the treatment closely. The owners were clearly satisfied with the results that were obtained, even with this modest weight loss. The questionnaires were shown to be an important tool in determining the causes of canine obesity, as well as in the follow-up of the treatment.

COMPUTED TOMOGRAPHIC ASSESSMENT OF BODY FAT IN BEAGLES

Obesity is the most common nutritional disorder in small animals. To establish a computed tomographic (CT) method for assessment of visceral and subcutaneous fat content in the dog, CT analysis was performed in normal and obese beagles. Fat area was measured by the level detection method at varied attenuation ranges and compared with body fat content estimated by the deuterium oxide dilution method. Fat area measured at L3 using the attenuation range of -135/-105 Hounsfield unit had the best correlation with body fat content (r = 0.98). Regional fat distribution was almost the same between normal and obese dogs, with more fat accumulation at L1-S1 than T10-T13. Moreover, visceral and subcutaneous fat area could be estimated separately. This CT method may contribute to both the clinical diagnosis and the study of canine obesity, especially for studies in the relationship between body fat distribution and obesity-associated diseases.

Abnormal cardiovascular responses to exercise during the development of obesity in dogs.

This study examined the control of cardiovascular dynamics in response to exercise during the development of obesity in dogs. Left atrial pressure (LAP), mean arterial pressure, and cardiac output (CO) were determined both at rest and in response to treadmill exercise (5.6 km/h, 10% grade) first during a control, lean state and then, once a week while the dogs were maintained on a high fat diet (HFD) for 4 weeks. Body weight increased from 22.8 +/- 1.1 to 33.1 +/- 2.0 kg after 4 weeks of HFD. The dogs developed mild hypertension with increases in resting CO, heart rate, and LAP. The response to exercise was characterized by a decrease in LAP when the dogs were lean and, in contrast, by a dramatic increase in LAP during the development of obesity. In addition, after the third week, the dogs could no longer maintain exercise at the original level. These results suggest that abnormal left ventricular function may occur very early during the development of canine obesity.

肥満犬における食餌療法の一治験例

It has been recommended that diets for the management of canine obesity should be prescribed on the basis of providing 60% of the calculated maintenance requirement at the ideal body weight. The purpose of this paper is to evaluate effects of a commercial weight-reduction diet on an overweight beagle. During this experiment the optimal calorie intake and changes in body weight of the obese dog were determined. Additionally, hematological and serum biochemical analysis were performed.The body weight before the experiment was 19.44 kg. When the weight-reduction regimen started, the authors estimated that the optimum body weight of the beagle was 15 kg. The diets were changed from the usual dog food to the prescribed one. The metabolizable energy intake was restricted from 700 to 506 kcal/day, and again to 440 kcal/day: that is, the calorie intake decreased to approximately 70% and 60% of the initial calorie intake, respectively. During this experiment, this dog lost 4.5 kg in weight over 3 months, reaching the target weight. While being fed the restrictive weight-reduction diet, the dog's body weight remained between 14.5 and 15.0 kg. When ad lib feeding using normal dog food was recontenued, the dog quickly regained the same energy intake level as the pre-experiment one, resulting in an increase in body weightThe blood and serum chemistry profile revealed no abnormalities before the test. The thyroidal function was normal. From these results, the patient was diagnosed as simple obesity. During the diet treatment, laboratory findings showed few changes. However, when the dog returned to its former obese condition, the red blood cell count. hemoglobin concentration and packed cell volume decreased. Total cholesterol and β-lipoprotein markedly increased and HDL-cholesterol declined. The activity of lactate dehydrogenase only showed an increase.These results demonstrated that there was a particular case that the recommended feeding calolie “the maintanance requirement×60%” in the diet therapy would not have a sufficienteffectonoverweightdogs-In such an instance, the calorie intake before the weight reduction might be the important indication in regimens. It was revealed that the relapse of obesity after the body weight reduction was drastic, and that the body weight rapidly increased and lipid metabolic system was remarkably affected. These abnormalities, after we discontinued the calolie.restriction, might be explained as the rebound phenomena after diet theranv.

Hyperinsulinemia induced by canine distemper virus infection of mice and its correlation with the appearance of obesity

1. 1. Weanling Swiss mice surviving an acute infection with canine distemper virus were persistently infected. Among these mice, up to 30% had hyperinsulinemia and this was followed by an obesity syndrome. 2. 2. Analysis of the lipid composition of various organs revealed that compared to control animals, the obese had an accumulation of triglycerides in both liver and adipose tissue. 3. 3. Studies on the lipid metabolism using a number of radioactive lipid precursors showed a specific accumulation of the triglycerides of the obese animals. 4. 4. A decrease of lipogenesis was observed in white adipose tissue of obese mice. Glycogenesis and serum glucose levels were unaffected during obesity. 5. 5. The model of canine distemper virus-induced obesity is compared with other experimental models.

Diagnosis and management of the overweight dog.

Abstract Canine obesity remains one of the most commonly encountered problems in small animal practice; yet the average owner rarely presents the dog because it has been recognized as being overweight. More frequently, the dog is presented because it is suffering from one of the numerous health problems that being overweight can cause. The present paper discusses the causes, development and clinical signs of obesity, the differential diagnosis of the condition and finally the management of cases.

Jaundice in Dogs and Cats

The aim of this study was to evaluate the serum biochemistry profile, inflammatory cytokines, adipokines and cardiovascular findings in obese dogs. Twenty obese and 20 normal weight healthy pet dogs were recruited into the study, where they underwent blood testing and assessment of cardiovascular function (blood pressure analysis, electrocardiography and echocardiography). Higher concentrations of total cholesterol, triglycerides, lactate dehydrogenase, total serum proteins, α-globulins, total bilirubin, insulin, insulin:glucose ratio, alkaline phosphate and alanine aminotransferase were observed in obese dogs than dogs of normal weight. There were no differences in concentrations of tumour necrosis factor (TNF)-α or interleukin (IL)-6 between the two groups. Obese dogs had higher serum leptin but lower adiponectin concentrations than dogs of normal weight. Systolic arterial blood pressure was higher in obese dogs than dogs of normal weight. The values for the thickness of the free wall of the left ventricle and interventricular septal thickness were greater at end-diastole in obese dogs compared to dogs of normal weight. Four of 20 obese dogs were determined to have obesity-related metabolic dysfunction (ORMD). The findings indicate that a chronic inflammatory state is not necessarily evident in obese dogs, as has been described in human beings, and the criteria used for ORMD can be used to define this syndrome in dogs. In this study, canine obesity was associated with cardiac and vascular dysfunction.