The effect of obesity and subsequent weight reduction on cardiac structure and function in dogs.

BACKGROUND: In people, the cardiovascular effects of obesity include systemic hypertension, cardiac remodelling and both systolic and diastolic dysfunction, whilst weight reduction can reverse myocardial remodelling and reduce risk of subsequent cardiovascular disease. To date, variable results are reported in studies of the effect of obesity and controlled weight reduction on cardiovascular morphology and function in dogs. This prospective study aimed to assess cardiac function, heart rate variability, cardiac biomarkers and body composition before and after weight reduction in pet dogs with obesity. Twenty-four client-owned dogs referred for weight management due to obesity were recruited. To assess the cardiac effects of obesity, body composition analysis (by dual energy X-ray absorptiometry, DEXA) and cardiovascular assessment (echocardiography, Doppler blood pressure, electrocardiography, cardiac biomarkers) were performed prior to weight management. Twelve dogs completed the study and reached target weight, receiving a further cardiovascular assessment and DEXA. A Wilcoxon-signed rank test was used to compare each variable pre- and post- weight reduction. RESULTS: Median (interquartile range) duration of weight loss was 224 days (124-245 days), percentage weight loss was 23% (18-31%) of starting weight. Median change in body fat mass was -50% (-44% to -55%; P = 0.004), whilst median change in lean mass was -7% (+ 1% to -18%, P = 0.083). Before weight reduction, diastolic dysfunction (evidence of impaired relaxation in all dogs), increased left ventricular wall thickness and mildly elevated systolic blood pressure (14/24 ≥ 160 mmHg, median 165 mmHg (140-183)) were common features in dogs with obesity. However, systolic left ventricular wall dimensions were the only variables that changed after weight reduction, with a decrease in both the systolic interventricular septum (P = 0.029) and systolic left ventricular free wall (P = 0.017). There was no evidence of decreased heart rate variability in dogs with obesity (P = 0.367), and no change in cardiac biomarker concentrations with weight reduction (N-terminal proBNP, P = 0.262; cardiac troponin I P = 0.657). CONCLUSIONS: Canine obesity results in diastolic dysfunction and left ventricular hypertrophy, the latter of which improves with significant weight and fat mass reduction. Further studies are required to clarify the clinical consequences of these findings.

Maintenance energy requirements in miniature colony dogs.

There are numerous reports of maintenance energy requirements (MER) in dogs, but little information is available about energy requirements of miniature dog breeds. In this prospective, observational, cohort study, we aimed to determine MER in dogs from a number of miniature breeds and to determine which factors were associated with it. Forty-two dogs participated in the study. MER was calculated by determining daily energy intake (EI) during a period of 196 days (28-359 days) when body weight did not change significantly (e.g. ±2% in 12 weeks). Estimated median MER was 473 kJ/kg(0.75) /day (285-766 kJ/kg(0.75) /day), that is, median 113 kcal/kg(0.75) /day (68-183 kcal/kg(0.75) /day). In the obese dogs that lost weight, median MER after weight loss was completed was 360 kJ/kg(0.75) /day (285-515 kJ/kg(0.75) /day), that is, 86 kcal/kg(0.75) /day, (68-123 kcal/kg(0.75) /day). Simple linear regression analysis suggested that three breeds (e.g. Chihuahua, p = 0.002; Yorkshire terrier, p = 0.039; dachshund, p = 0.035) had an effect on MER. In addition to breed, simple linear regression revealed that neuter status (p = 0.079) and having previously been overweight (p = 0.002) were also of significance. However, with multiple linear regression analysis, only previous overweight status (MER less in dogs previously overweight p = 0.008) and breed (MER greater in Yorkshire terriers [p = 0.029] and less in Chihuahuas [p = 0.089]) remained in the final model. This study is the first to estimate MER in dogs of miniature breeds. Although further information from pet dogs is now needed, the current work will be useful for setting energy and nutrient requirement in such dogs for the future.

Weight loss outcomes are generally worse for dogs and cats with class II obesity, defined as > 40% overweight.

In pet dogs and cats, adiposity is most-often estimated clinically using a 9-category body condition score (BCS), with BCS 9 equating to ~ 40% overweight. Animals that are more overweight (> 40%) are seen in clinical practice but are not appropriately depicted by descriptions in the existing categories. To determine whether being > 40% overweight has clinical relevance, this study aimed to compare the outcomes of weight management in animals that were > 40% overweight with those < 40% overweight. Records of dogs and cats attending a specialist obesity care clinic, where adiposity is determined using dual-energy X-ray absorptiometry (DXA), were reviewed. Animals were assigned to two classes (class I ≤ 40% overweight: 118/398 [40%] dogs and 68/116 [59%] cats; class II, > 40% overweight: 180/398 [60%] dogs and 48/116 [41%] cats) based on DXA results, and weight loss outcomes were compared. Fewer class II dogs obesity completed weight management than class I dogs (P < 0.001), rate of weight loss was also slower (P = 0.012) and lean tissue loss greater (P < 0.001). Compared with class I, cats with class II obesity lost more weight (P = 0.048) albeit over a longer period (P = 0.043) leading to greater lean tissue loss (P = 0.004). Approximately half the pets presenting to a specialist clinic were have class II obesity (> 40% overweight), and some weight loss outcomes are worse for these animals.

"Just old age" - a qualitative investigation of owner and veterinary professional experiences of and attitudes to ageing in dogs in the UK.

OBJECTIVES: Many UK dogs live into old age, but owners may not recognise or report age-associated signs of disease which lead to negative welfare. This study investigated dog owner and veterinary professional experiences and attitudes towards ageing in dogs, how health care is offered, barriers to its delivery, and some best-practice solutions. MATERIALS AND METHODS: In-depth semi-structured interviews were conducted with 15 owners of 21 dogs (aged 8 to 17 years mean: 13) and 11 veterinary professional (eight veterinary surgeons, two nurses and one physiotherapist). Open-text responses from 61 dog owners were collected using an online survey. Transcripts and survey responses were inductively coded into themes. RESULTS: Four themes were constructed: "just old age", barriers to care, trust in veterinary surgeons, and tools to improve health care. Age-related changes were mostly perceived as "just old age" by dog owners. Many dogs were no longer vaccinated and did not attend check-ups unless owners identified a problem. The greatest barriers to health care were finances (dog owners), owner awareness, willingness to act and consultation time (veterinary professionals). Trust in veterinary professionals was more likely when dog owner experienced continuity, prioritisation of care, clear communication and an accessible, knowledgeable and empathic veterinary professional. Participants suggested that senior health care and communication between dog owners and veterinary professionals could be improved through questionnaires, and evidence-based online information. CLINICAL SIGNIFICANCE: Opportunities to educate owners on which clinical signs represent healthy or pathological ageing are being missed. Resources should be developed to guide on best-practice discussions in consultations, encourage more owners to recognise clinical signs and to seek and trust veterinary advice.

Sodium/glucose cotransporter-1, sweet receptor, and disaccharidase expression in the intestine of the domestic dog and cat: two species of different dietary habit.

The domestic cat (Felis catus), a carnivore, naturally eats a very low carbohydrate diet. In contrast, the dog (Canis familiaris), a carno-omnivore, has a varied diet. This study was performed to determine the expression of the intestinal brush border membrane sodium/glucose cotransporter, SGLT1, sweet receptor, T1R2/T1R3, and disaccharidases in these species adapted to contrasting diets. The expression (this includes function) of SGLT1, sucrase, maltase and lactase were determined using purified brush border membrane vesicles and by quantitative immunohistochemistry of fixed tissues. The pattern of expression of subunits of the sweet receptor T1R2 and T1R3 was assessed using fluorescent immunohistochemistry. In proximal, middle, and distal small intestine, SGLT1 function in dogs was 1.9- to 2.3-fold higher than in cats (P = 0.037, P = 0.0011, P = 0.027, respectively), and SGLT1 protein abundance followed an identical pattern. Both cats and dogs express T1R3 in a subset of intestinal epithelial cells, and dogs, but not cats, express T1R2. In proximal and middle regions, there were 3.1- and 1.6-fold higher lactase (P = 0.006 and P = 0.019), 4.4- and 2.9-fold higher sucrase (both P < 0.0001), and 4.6- and 3.1-fold higher maltase activity (P = 0.0026 and P = 0.0005), respectively, in the intestine of dogs compared with cats. Dogs have a potential higher capacity to digest and absorb carbohydrates than cats. Cats may suffer from carbohydrate malabsorption following ingestion of high-carbohydrate meals. However, dogs have a digestive ability to cope with diets containing significant levels of carbohydrate.

Imprecision when using measuring cups to weigh out extruded dry kibbled food.

Many pet cats and dogs are fed dry extruded kibbled food by measuring cup, yet the precision and accuracy of this feeding strategy is not known. Over 12 studies, we assessed precision and accuracy of weighing out food portions, of various dry kibbled foods, by measuring cup. Poor precision was noted in all studies, with intra- and inter-subject coefficients of variation ranging from 2 to 13% and 2 to 28% respectively. Variable accuracy was also noted, which ranged from an 18% under-estimate to an 80% over-estimate in portion size. No specific factors were associated with imprecision, but the degree of inaccuracy was negatively associated with portion size (R = -0.67, p = 0.022), and positively associated with the number of subjects participating in the study (R = 0.60, p = 0.048). This is the first study to document imprecision and inaccuracy of using measuring cups to estimate portions of extruded dry kibbled food. Over time, such errors could contribute to insidious weight gain in companion animals, potentially contributing to the development of obesity. Imprecision in measuring food portions could also contribute to failure of weight management programmes for obese animals.

Maintenance energy requirements in cats following controlled weight loss: An observational study.

There is a paucity of information regarding the phenomenon of weight regain after successful weight reduction in cats. This study aimed to estimate post-weight reduction maintenance energy requirements (MER) required to maintain stable weight in a group of pet cats. Nineteen cats that had successfully completed a controlled weight reduction programme were enrolled. For inclusion, at least 2 months of follow-up had to be available for review, and the maximum change in weight during maintenance was ±2%. Post-weight-reduction MER was estimated by determining dietary energy consumption from owner diary records. The Friedman test was used to compare bodyweight and energy intake at different stages of weight management. Simple and multiple linear regression were used to identify factors associated with post-weight-reduction MER. The median (interquartile range) duration of weight maintenance was 179 days (119-408 days) and, during this time, MER was 273 ± 56.7 kJ per kg0.67 ideal bodyweight (IBW) per day. Post-weight-reduction MER was greater than metabolisable energy intake at the end (233 ± 29.5 kJ IBW per kg0.67 per day; P < 0.001) but not the start (255 ± 38.6 kJ per kg0.67 IBW per day; P = 0.148) of the weight reduction period. Using simple and multiple linear regression, the only variable that was associated with post-weight reduction MER was the mean ME intake during weight reduction (r2 = 0.349, P = 0.008). Post-weight-reduction MER at the lower limits of MER recommendations for pet cats might predispose to weight regain during the weight maintenance phase.

A randomized, open-label, positively-controlled field trial of a hydrolyzed protein diet in dogs with chronic small bowel enteropathy.

BACKGROUND: Hydrolyzed protein diets are commonly used to manage canine chronic enteropathies (CE), but their efficacy has not yet been critically evaluated. HYPOTHESIS: A hydrolyzed protein diet is superior to that of a highly digestible (control) diet in the management of CE in dogs. ANIMALS: Twenty-six dogs (18 test diet, 8 control diet) referred for investigation and management of naturally occurring chronic small intestinal disease. METHODS: Randomized, open-label, positively controlled trial. After a full diagnostic investigation, which included endoscopy, dogs were assigned either to the test diet or control diet on a 2:1 basis (test:control). Cases were re-evaluated 3 times (at approximately 3, 6-12 months, and 3 years). Outcome measures included response of clinical signs (complete, partial, none), change in severity of signs (based upon clinical disease activity index; canine inflammatory bowel disease activity index [CIBDAI]), change in body weight, and need for other therapy. RESULTS: There were no significant differences in baseline characteristics (eg, signalment, body weight, and duration of clinical signs), and histopathologic severity between test and control diet groups. However, despite randomization, CIBDAI was significantly higher in the test diet group (P=.013). Most dogs had responded by first evaluation, with no difference between groups (P=.87). However, significantly more dogs on the test diet remained asymptomatic at both the second (P=.0012) and third (P<.001) re-evaluation, and the decrease in CIBDAI was significantly greater (P=.010). CONCLUSIONS AND CLINICAL IMPORTANCE: A hydrolyzed protein diet can be highly effective for long-term management of canine chronic small bowel enteropathy.

An open-label randomised clinical trial to compare the efficacy of dietary caloric restriction and physical activity for weight loss in overweight pet dogs.

Canine obesity is usually managed with a combination of dietary caloric restriction and increasing physical activity, but no previous study has compared both of these strategies in a prospective randomised controlled trial. Thirteen overweight dogs (body condition score 6-9/9) were randomised to one of two interventions: dietary caloric restriction or physical activity. The dietary caloric restriction intervention comprised feeding a therapeutic weight loss diet, while the physical activity intervention comprised increasing the dog's current physical activity pattern by at least a third. The primary outcome measure was change in body weight, while secondary outcome measures included change in neck, thorax and abdominal circumference and change in physical activity measured by triaxial accelerometer. Bodyweight decreased significantly with the dietary caloric restriction (median -10% of starting body weight [SBW], 5 to -12%; P=0.028) but not with the physical activity intervention (-2% SBW, +3% to -6%; P=0.107). Abdominal circumference (dietary caloric restriction: median -12.0%; physical activity: median -7.8%, P=0.016) and thoracic circumference (dietary caloric restriction: median -7.5%, P=0.031; physical activity: median -3.6%, P=0.031) changed significantly in both groups. There was no change in activity levels within the dietary caloric restriction group, but vigorous activity increased significantly in the physical activity group (P=0.016). Dietary caloric restriction was more effective than physical activity for controlled weight loss in overweight pet dogs. Although advising owners to increase their dog's activity by a third led to a modest increase in measured vigorous physical activity, this was insufficient to promote weight loss on its own.

How often do veterinarians assess the bodyweight and body condition of dogs?

Measurements of bodyweight and body condition are useful for monitoring the state of health of companion animals, but the frequency with which they are used by veterinarians in general practice is not known. Information derived from 148 dogs was analysed to determine how often their bodyweight and body condition had been assessed. Bodyweight had been measured at least once in 103 (70 per cent) of the dogs. The median time between the measurements was 114 days (range five days to 6.8 years), and the median number of consultations per measurement was four (range one to 44). Body composition had been assessed subjectively in 43 (29 per cent) of the dogs. The median time between the assessments was 216 days (21 days to 6.26 years) and the median number of consultations per assessment was seven (two to 43). A recognised body condition score had been assessed in only one dog on one occasion.

Successful resolution of dermatophyte mycetoma following terbinafine treatment in two cats.

Microsporum canis sensitive to itraconazole and terbinafine was isolated from two cats presented with generalized dermatophytosis and dermatophyte mycetoma. Itraconazole therapy was withdrawn through lack of efficacy in one cat (a Persian) and unacceptable adverse effects in the other (a Maine Coon). Both cats achieved clinical and mycological cure after 12-14 weeks therapy with 26-31 mg kg(-1) terbinafine every 24 h per os (PO). Clinical signs in the Maine Coon resolved completely after 7 weeks treatment. Four weeks of therapy with additional weekly washes with a 2% chlorhexidine/2% miconazole shampoo following clipping produced a 98% reduction in the Persian cat's mycetoma, which was then surgically excised. Recurrent generalized dermatophytosis in the Persian cat has been managed with pulse therapy with 26 mg kg(-1) terbinafine every 24 h PO for 1 week in every month. No underlying conditions predisposing to dermatophytosis were found in either cat despite extensive investigation. Terbinafine administration was associated with mild to moderate lethargy in the Persian cat, but no other adverse effects or changes in blood parameters were seen. To the best of the authors' knowledge this is the first report of a dermatophyte mycetoma in a Maine Coon and of successful resolution of this condition in cats following terbinafine therapy.

Gastric carcinoma in canines and humans, a review.

Gastric carcinoma (GC) is the most common neoplasm in the stomach of dogs. Although incidence in the general population is reported to be low, breed-specific GC has a high incidence. Median age at presentation ranges from 8 to approximately 10 years. The disease is mostly located in the lesser curvature and antropyloric region of the stomach. Unfortunately, diagnosis is usually made when the disease is at an advanced stage and, therefore, prognosis is poor. Due to similarities in clinical presentation, diagnosis, histology and prognosis, canine GC may serve as a valuable model for human GC. Extensive pedigrees of canine gastric carcinoma cases could reveal insights for human gastric carcinoma. Putative species differences include the role of Helicobacter in pathogenesis, the wide array of genetic data and screening available for humans, and treatment protocols that are available for human GC.

The Financial Costs, Behaviour and Psychology of Obesity: A One Health Analysis.

People who are overweight or have obesity are estimated to comprise 30% of the global population and up to 59% of companion dogs and cats are estimated to be above their optimal body weight. The prevalence of human and companion obesity is increasing. The direct and indirect costs of obesity and associated comorbidities are significant for human and veterinary healthcare. There are numerous similarities between obesity in people and companion animals, likely related to the shared environmental and lifestyle elements of this multifactorial disease. While the study of human obesity is relatively robust, research conducted in pets is generally limited to small studies, studies with cross-sectional designs or reports that have yet to be replicated. Greater understanding of human obesity may elucidate some of the factors driving the more recent rise in pet obesity. In particular, there are overlapping features of obesity in children and pets that are, in part, related to dependency on their 'parents' for care and feeding. When feeding is used in a coercive and controlling fashion, it may lead to undesirable feeding behaviour and increase the risk for obesity. A 'responsive parenting' intervention teaches parents to respond appropriately to hunger-satiety cues and to recognize and respond to others' distress. Such interventions may impact on childhood overweight and obesity and have the potential to be adapted for use with companion animals. Social behaviour towards people with obesity or owners of pets with obesity is often driven by beliefs about the cause of the obesity. Educating healthcare professionals and the public about the multifactorial nature of this complex disease process is a fundamental step in reducing the bias and stigma associated with obesity. Children living in low-income households have particularly high rates of obesity and as household income falls, rates of obesity also rise in pets and their owners. There are risk regulators (i.e. dynamic components of interconnected systems that influence obesity-related behaviours) and internal factors (i.e. biological determinants of obesity) that may influence the development of both childhood and pet obesity, and poverty may intersect with these variables to exacerbate obesity in low-income environments. This review discusses the costs, behaviours and psychology related to obesity in people and pets, and also proposes potential techniques that can be considered for prevention and treatment of this disease in pets. A 'One Health' approach to obesity suggests that an understanding of human obesity may elucidate some of the factors driving the more recent rise in pet obesity.

The association between dog ownership or dog walking and fitness or weight status in childhood.

BACKGROUND: Health benefits of dog walking are established in adults: dog owners are on average more physically active, and those walking their dogs regularly have lower weight status than those who do not. However, there has been little research on children. OBJECTIVES: This study aimed to examine the association between dog ownership or dog walking and childhood fitness or weight status. METHODS: A survey of pet ownership and involvement in dog walking was combined with fitness and weight status measurements of 1021 9 to 10-year-old children in the Liverpool SportsLinx study. RESULTS: We found little evidence to support that children who live with, or walk with, dogs are any fitter or less likely to be obese than those who do not. CONCLUSIONS: This is an important finding, as it suggests that the activity that children currently do with dogs is not sufficient enough to impact weight status or fitness.

Pyloric localisation in 57 dogs of breeds susceptible to gastric dilatation-volvulus in the UK using computed tomography.

OBJECTIVE: Describe the location of the pylorus using CT in dog breeds susceptible to gastric dilatation-volvulus in the UK. METHODS: Descriptive anatomical study. Abdominal CT scans of 57 client-owned dogs were reviewed to assess pyloric position relative to the 9th, 10th, 11th and 13th ribs and 2 and 3 cm caudal to the 13th rib at the 8, 9 and 10 o'clock positions. The angle of the pylorus from the centre of the abdominal cavity relative to the sagittal plane was also determined. RESULTS: In 88 per cent of cases, the pylorus was located in the right cranioventral abdomen with 63 per cent positioned at the 9-10 o'clock position. The overall distance between the pylorus and right abdominal wall (RAW) at the 13th rib 10 o'clock position was equivalent to 29 per cent of ventral abdominal length, significantly greater than the median overall distance of ∼14 per cent of ventral abdominal length between the pylorus and RAW at the 9th or 10th rib 10 o'clock position (P<0.0001). CLINICAL SIGNIFICANCE: Common gastropexy locations may result in considerable displacement of the pylorus relative to its natural anatomic location. Further case-control studies are required to assess the clinical significance of this finding.

Clinical leishmaniasis in dogs living in the UK.

OBJECTIVES: To investigate the prevalence of leishmaniasis in dogs in the UK and to describe clinical presentation, clinicopathological abnormalities, therapeutic protocols and outcome in this non-endemic country. MATERIALS AND METHODS: Medical records of dogs diagnosed with leishmaniasis at seven referral centres in the UK were retrospectively reviewed. RESULTS: The prevalence was between 0·007 and 0·04% with a higher number of cases in southern England. All dogs had a history of travel to or from an endemic country. Lethargy, dermatological disease, decreased appetite and lameness were the most common reasons for presentation. Allopurinol was used alone for treatment in the majority of cases. CLINICAL SIGNIFICANCE: Although rare, leishmaniasis should be considered in dogs in the UK if they have compatible clinical signs and history of travel to or from endemic areas.

Effect of intestinal inflammation on fecal elastase concentration in dogs.

BACKGROUND: A commercially available ELISA kit for fecal elastase measurement can be used in the diagnosis of exocrine pancreatic insufficiency (EPI) in dogs. However, other causes of diarrhea also may affect fecal elastase concentration. OBJECTIVE: This study was undertaken to determine whether intestinal inflammation alters fecal elastase concentration in dogs. METHODS: Fecal elastase concentration was measured with an ELISA kit in the following groups of dogs: group 1 (n=16), control dogs, without gastrointestinal disease; group 2 (n=14), dogs with diarrhea and no histopathologic evidence of intestinal inflammation; and group 3 (n=12), dogs with diarrhea and histopathologic evidence of intestinal inflammation. Serum trypsin-like immunoreactivity (TLI) was determined in dogs with diarrhea to rule out EPI. RESULTS: All dogs in groups 2 and 3 had serum TLI concentrations >5 microg/L, ruling out EPI. No statistically significant difference was found in fecal elastase concentration among the 3 groups of dogs (P=.969). CONCLUSIONS: The results indicate that intestinal inflammation does not affect fecal elastase concentration, such that test results may be used to exclude a diagnosis of EPI even in animals with inflammatory bowel disease.

Unusual vascular ring anomaly associated with a persistent right aortic arch in two dogs.

An unusual vascular ring anomaly consisting of a persistent right aortic arch and a left ligamentum arteriosum extending from the main pulmonary artery to an aberrant left subclavian artery and left aortic arch remnant complex was identified in a German shepherd dog and a great Dane. The left subclavian artery and left aortic arch remnant complex originated at the junction between the right distal aortic arch and the descending aorta and coursed dorsal to the oesophagus in a cranial direction. The attachment of the ligamentum arteriosum to the aberrant left subclavian artery was approximately 5 cm cranial to the point of origin of the aberrant left subclavian artery and left aortic arch remnant complex from the descending aorta in both dogs. This anomaly observed in both dogs is similar to an anomaly reported in humans, in which a persistent right aortic arch is found in conjunction with an aberrant left subclavian artery and a left aortic arch remnant (Kommerell's diverticulum). Surgical ligation and division of the left ligamentum arteriosum in both dogs, along with division of the left subclavian artery in the great Dane, resulted in resolution of clinical signs in both of the dogs in this report.

Best in show but not best shape: a photographic assessment of show dog body condition.

Previous studies suggest that owners often wrongly perceive overweight dogs to be in normal condition. The body shape of dogs attending shows might influence owners' perceptions, with online images of overweight show winners having a negative effect. This was an observational in silico study of canine body condition. 14 obese-prone breeds and 14 matched non-obese-probe breeds were first selected, and one operator then used an online search engine to identify 40 images, per breed, of dogs that had appeared at a major national UK show (Crufts). After images were anonymised and coded, a second observer subjectively assessed body condition, in a single sitting, using a previously validated method. Of 1120 photographs initially identified, 960 were suitable for assessing body condition, with all unsuitable images being from longhaired breeds. None of the dogs (0 per cent) were underweight, 708 (74 per cent) were in ideal condition and 252 (26 per cent) were overweight. Pugs, basset hounds and Labrador retrievers were most likely to be overweight, while standard poodles, Rhodesian ridgebacks, Hungarian vizslas and Dobermanns were least likely to be overweight. Given the proportion of show dogs from some breeds that are overweight, breed standards should be redefined to be consistent with a dog in optimal body condition.

Cohort Study of the Success of Controlled Weight Loss Programs for Obese Dogs.

BACKGROUND: Most weight loss studies in obese dogs assess rate and percentage of weight loss in the first 2-3 months, rather than the likelihood of successfully reaching target weight. OBJECTIVE: To determine outcome of controlled weight loss programs for obese dogs, and to determine the factors associated with successful completion. ANIMALS: 143 obese dogs undergoing a controlled weight loss program. METHODS: This was a cohort study of obese dogs attending a referral weight management clinic. Dogs were studied during their period of weight loss, and cases classified according to outcome as "completed" (reached target weight), "euthanized" (was euthanized before reaching target weight), or "stopped prematurely" (program stopped early for other reasons). Factors associated with successful completion were assessed using simple and multiple logistic regression. RESULTS: 87/143 dogs (61%) completed their weight loss program, 11 [8%] died or were euthanized, and the remaining 45 [32%] stopped prematurely. Reasons for dogs stopping prematurely included inability to contact owner, refusal to comply with weight management advice, or development of another illness. Successful weight loss was positively associated with a faster rate (P < .001), a longer duration (P < .001), and feeding a dried weight management diet (P = .010), but negatively associated with starting body fat (P < .001), and use of dirlotapide (P = .0046). CONCLUSIONS AND CLINICAL RELEVANCE: Just over half of all obese dogs on a controlled weight loss program reach their target weight. Future studies should better clarify reasons for success in individual cases, and also the role of factors such as activity and behavioral modification.