Experiments with rectangular supersonic jets with potential noise reduction technology.

This paper describes the aeroacoustics experiments conducted with supersonic jets, exhausting from rectangular nozzles with an aspect ratio of 2, to examine the jet noise reduction by two different methods. The first method involves the use of fluid inserts, which are produced by distributed air blowing into the diverging section of a convergent-divergent exhaust nozzle. The second method involves the integration of fluid shields in dual flow rectangular jets. In the dual flow nozzle, a single shield below the exit is augmented with fluid shields extending on both sides of the rectangular jet. The purpose of the extended bypass flow is to reduce the noise radiated to the sides of a jet aircraft. In addition to the nozzles with the two noise reduction configurations, acoustic measurements are performed with a single flow rectangular jet, referred to as the baseline. In all cases, the jets are operated as overexpanded, shock-containing jets. In some cases, the jets are operated with the core flow mixtures of helium and air to simulate high temperature jets. The far-field noise measurements are performed on an arc with the microphones approximately 70 equivalent nozzle diameters from the nozzle exit. For the purposes of assessing the noise reduction capability of the dual stream jet, comparisons are made with a baseline rectangular jet on an equal thrust per unit exit area basis. The nondimensional acoustic spectra and overall sound pressure level directivities are shown and compared.

Faecal calcium excretion does not decrease during long-term feeding of a low-calcium diet in adult dogs.

According to a previous meta-analysis, adult dogs do not notably increase calcium absorption from the gastrointestinal tract when calcium intake is decreased. This results in a negative calcium balance even with a moderate calcium reduction. In this study we wanted to verify (i) whether a negative calcium balance occurs at a calcium intake equivalent to NRC (2006) (Nutrient requirements of dogs and cats, 2006, The National Academies Press, Washington, DC) minimal requirements, and if so (ii) whether the negative calcium balance will persist for up to 6 months on a low-calcium diet. After a pre-feeding period of at least 18 weeks with calcium intake slightly exceeding maintenance requirements (200 mg/kg body weight0.75 ), 12 dogs (6 Beagles, 6 Foxhound crossbreds) were fed a low-calcium diet for 28 weeks. One dog was removed from the trial for reasons unrelated to the study at week 23. Calcium intake amounted to 60 mg/kg body weight0.75 corresponding to the minimal requirement for maintenance in dogs (NRC, 2006 (Nutrient requirements of dogs and cats, 2006, The National Academies Press, Washington, DC)). Digestion trials were carried out at week 7, 14, 21 and 28 of the low calcium feeding period. At these time points, and at week 18 of the pre-trial, blood samples were taken and analysed for calcium, ionised calcium, phosphorus, parathyroid hormone, vitamin D, serum crosslaps and bone alkaline phosphatase. Apparent calcium digestibility was negative throughout the study, suggesting a negative calcium balance. There was no systematic decrease in faecal calcium excretion. Serum calcium, ionised calcium and phosphorus remained within the reference range. Serum crosslaps increased continuously from baseline to week 28 of trial, with averages increasing from 0.102 ng/ml to 0.279 ng/ml, suggesting osteoclastic activity, indicative of calcium mobilisation from the skeleton. The study supports the theory of a lack of adaptation of intestinal calcium absorption from diets with relatively low calcium content in dogs. This agrees with clinical findings in dogs eating low-calcium diet.

Systematic review of clinical practice guidelines in kidney transplantation.

BACKGROUND: Clinical practice guidelines (CPGs) are widely used to inform the development of protocols for clinical management. Previous work has demonstrated that the quality of CPGs varies widely. This systematic review aimed to determine the quality of CPGs in kidney transplantation in the UK. METHODS: CPGs in kidney transplantation published between 2010 and 2017 were identified through searches of MEDLINE, NHS NICE Evidence, and websites of relevant UK societies. Using the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool, three appraisers rated the quality of CPGs across six domains, the overall quality of each CPG, and whether it should be recommended for future use. Domain scores were calculated, and inter-rater reliability using the intraclass correlation coefficient (ICC) was reported. RESULTS: Thirteen CPGs met the inclusion criteria. The domain 'clarity of presentation' scored highest, followed closely by 'scope and purpose'. The poorest scoring domains were 'applicability' and 'editorial independence'. Editorial independence also had the widest range of scores. Of the 13 CPGs, one was not recommended for future use, seven were recommended for use with modifications, and five for future use with no need for modification. Mean overall CPG quality was 5 (range 3-6) of a maximum score of 7, and mean inter-rater reliability was substantial with an ICC of 0·71. CONCLUSION: UK CPGs scored satisfactorily, although with wide variation in how well each domain scored both within and across CPGs. The quality of UK CPGs can still be improved.

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.

Demonstration of uniformity of calcium absorption in adult dogs and cats.

A meta-analysis was conducted to understand quantitative aspects of calcium (Ca) and phosphorus (P) absorption in adult dogs and cats. 34 studies in dogs and 14 studies in cats met the criteria for inclusion in the meta-analysis. Intake and faecal excretion values of Ca and P were subjected to a modified Lucas test and subsequent regression analyses. According to the current scientific consensus, Ca true digestibility (absorption) should increase at low Ca intake and decrease at high Ca intake. If true, this should result in a nonlinear relationship between the percentage of Ca excreted and dietary Ca intake. The present meta-analysis showed a highly significant linear relationship (p < 0.0001) between Ca intake and Ca excretion suggesting a lack of systematic quantitative adaptation in true Ca digestibility. This finding suggests either that the time period covered by standard digestion trials is too short to induce adaptation mechanisms or that dogs and cats at maintenance will not efficiently alter quantitative Ca absorption percentage according to the amount ingested. If the latter is true, a dietary Ca supply differing greatly from the recommended dietary intake might impair the health of cats and dogs when fed long term. The data plots for P intake and faecal excretion were less uniform suggesting other factors not just dietary intake influence faecal P excretion. In adult cats, the dietary Ca:P ratio strongly influenced the true digestibility of P, whereas this effect was less marked in adult dogs. Faecal P excretion was significantly correlated to faecal Ca excretion in both species (p < 0.0001), and surprisingly, the level of P intake did not appear to be an important determinant of true digestibility of P.

Feeding obese dogs during weight loss is on average cost-neutral.

OBJECTIVES: The cost of feeding a purpose-formulated weight loss diet may deter owners of obese dogs from proceeding with a weight loss programme. The current study aimed to compare average food costs during weight loss with those before weight loss. MATERIALS AND METHODS: Average daily food costs, for before and during weight loss, were calculated in 22 obese dogs that had successfully completed weight management. RESULTS: The median food cost before weight loss was £0 · 52/day (£0 · 24-3 · 31/day), for main meal only, and £0 · 64/day (£0 · 26-3 · 31/day) for main meal and additional food (table scraps and treats). The median food cost during weight loss was £0 · 90/day (£0 · 26-1 · 36/day), and no additional food was given. The average daily feeding costs during weight loss did not differ from pre-weight-loss costs, either with (P = 0 · 425) or without (P = 0 · 222) the additional food included. CLINICAL SIGNIFICANCE: Knowledge that average diet costs do not significantly differ from food costs prior to weight loss may help veterinarians to persuade owners to enrol obese dogs in a weight management programme.

Antifungal prophylaxis in liver transplantation: a systematic review and network meta-analysis.

Invasive fungal infections (IFIs) cause significant morbidity and mortality in liver transplant recipients, but the need and best agent for prophylaxis is uncertain. A comprehensive literature search was performed to identify randomized controlled trials comparing regimens for antifungal prophylaxis in liver transplant recipients. Direct comparisons were made between treatments using random-effects meta-analysis and a Bayesian network meta-analysis was performed for the primary end point of proven IFI. Fourteen studies met inclusion criteria, reporting comparisons of fluconazole, liposomal amphotericin B (L-AmB), itraconazole, micafungin and placebo. Overall, antifungal prophylaxis reduced the rate of proven IFI (odds ratio [OR] 0.37, confidence interval [CI] 0.19-0.72, p = 0.003), suspected or proven IFI (OR 0.40, CI 0.25-0.66, p = 0.0003) and mortality due to IFI (OR 0.32, CI 0.10-0.83, p = 0.02) when compared to placebo. All-cause mortality was not significantly affected. There was no difference in risk of adverse events requiring cessation of prophylaxis (OR 1.11, 95% CI 0.48-2.55, p = 0.81). In the network meta-analysis an equivalent reduction in the rate of IFI was seen with fluconazole (OR 0.21, CI 0.06-0.57) and L-AmB (OR 0.21, CI 0.05-0.71) compared with placebo. Routine prophylaxis with fluconazole or L-AmB reduces the incidence of IFI following liver transplantation, and the available evidence suggests that the two are equivalent in efficacy.

Oxygenation and ventilation characteristics in obese sedated dogs before and after weight loss: a clinical trial.

This prospective clinical study examined the effect of obesity and subsequent weight loss on oxygenation and ventilation during deep sedation in pet dogs. Data from nine dogs completing a formalised weight loss programme were evaluated. Dual-energy X-ray absorptiometry (DEXA) was used to quantify body fat mass prior to and after weight loss. Dogs were deeply sedated and positioned in dorsal recumbency. Sedation was scored using a semi-objective scheme. As part of the monitoring of sedation, arterial oxygen partial pressure (PaO2) and arterial carbon dioxide partial pressure (PaCO2) were measured after 10 min in dorsal recumbency. Oxygen saturation of haemoglobin (SpO2) was monitored continuously using pulse oximetry, starting oxygen supplementation where indicated (SpO2<90%) via a face mask. Morphometric measurements were taken from DEXA images and compared before and after weight loss. Several oxygen indices were calculated and correlated with body fat variables evaluated by DEXA. All body fat variables improved significantly after weight loss. PaO2 increased from 27.9±19.2 kPa to 34.8±24.4 kPa, while FiO2 decreased from 0.74±0.31 to 0.66±0.35. Morphometric measurements improved significantly after weight loss. PaO2/FiO2 (inspired oxygen fraction) and Pa/AO2 (ratio of PaO2 to alveolar PO2) also improved significantly, but there was no change in f-shunt and PaCO2 after weight loss. On multiple linear regression analysis, all oxygen indices were negatively associated with thoracic fat percentage. In conclusion, obesity decreases oxygenation in dogs during deep sedation. Oxygenation status improves with successful weight loss, but ventilation is not influenced by obesity.

Systematic review and meta-analysis of hypothermic machine perfusion versus static cold storage of kidney allografts on transplant outcomes.

BACKGROUND: Adequate preservation of renal allografts for transplantation is important for maintaining and improving transplant outcomes. There are two prevalent methods: hypothermic machine perfusion and static cold storage. The preferred method of storage, however, remains controversial. The objective was to review systematically the evidence comparing outcomes from these two modalities. METHODS: A literature search was performed using MEDLINE, Embase, the Cochrane Library, the Transplant Library and the International Clinical Trials Registry Platform. The final date for searches was 30 November 2012. Studies were assessed for methodological quality. Summary effects were calculated as relative risk (RR) with 95 per cent confidence interval (c.i.). Randomized clinical trials (RCTs) and non-RCTs were included, but evaluated separately. Results from RCTs alone were used for meta-analysis. RESULTS: Eighteen studies met the inclusion criteria, including seven RCTs (1475 kidneys) and 11 non-RCTs (728 kidneys). The overall risk of delayed graft function was lower with hypothermic machine perfusion than static cold storage (RR 0·81, 95 per cent c.i. 0·71 to 0·92; P = 0·002). There was no difference in the rate of primary non-function (RR 1·15, 0·46 to 2·90; P = 0·767). There was a faster initial fall in the level of serum creatinine with hypothermic machine perfusion in two RCTs, but not in another. There was no relationship between rates of acute rejection or patient survival and the method of preservation. CONCLUSION: Data from the included studies suggest that hypothermic machine perfusion reduces delayed graft function compared with static cold storage. There was no difference in primary non-function, acute rejection, long-term renal function or patient survival. A difference in renal graft survival is uncertain.

Effect of weight loss in obese dogs on indicators of renal function or disease.

BACKGROUND: Obesity is a common medical disorder in dogs, and can predispose to a number of diseases. Human obesity is a risk factor for the development and progression of chronic kidney disease. OBJECTIVES: To investigate the possible association of weight loss on plasma and renal biomarkers of kidney health. ANIMALS: Thirty-seven obese dogs that lost weight were included in the study. METHODS: Prospective observational study. Three novel biomarkers of renal functional impairment, disease, or both (homocysteine, cystatin C, and clusterin), in addition to traditional markers of chronic renal failure (serum urea and creatinine, urine specific gravity [USG], urine protein-creatinine ratio [UPCR], and urine albumin corrected by creatinine [UAC]) before and after weight loss in dogs with naturally occurring obesity were investigated. RESULTS: Urea (P = .043) and USG (P = .012) were both greater after weight loss than before loss, whilst UPCR, UAC, and creatinine were less after weight loss (P = .032, P = .006, and P = .026, respectively). Homocysteine (P < .001), cystatin C (P < .001) and clusterin (P < .001) all decreased upon weight loss. Multiple linear regression analysis revealed associations between percentage weight loss (greater weight loss, more lean tissue loss; r = -0.67, r(2) = 0.45, P < .001) and before-loss plasma clusterin concentration (greater clusterin, more lean tissue loss; r = 0.48, r(2) = 0.23, P = .003). CONCLUSION AND CLINICAL IMPORTANCE: These results suggest possible subclinical alterations in renal function in canine obesity, which improve with weight loss. Further work is required to determine the nature of these alterations and, most notably, the reason for the association between before loss plasma clusterin and subsequent lean tissue loss during weight management.

Preservation solutions for static cold storage of kidney allografts: a systematic review and meta-analysis.

Static cold storage is the most prevalent method for renal allograft preservation. Several solutions have been designed to counteract the detrimental effects of cold ischemia and reperfusion. The aim of this study was to appraise the evidence for the currently available preservation solutions. We performed a systematic literature search using MEDLINE, EMBASE, the Cochrane Library, the Transplant Library and trial registries. Inclusion criteria specified any comparative, prospective study for deceased donor renal allografts. Studies were assessed for methodological quality. The primary outcome was delayed graft function (DGF). Fifteen trials with a total of 3584 kidneys were included. Eurocollins was associated with a higher risk of DGF than University of Wisconsin solution (UW) in two randomized controlled trials (RCTs) and histidine-tryptophan-ketoglutarate (HTK) in two RCTs. UW was associated with an equal risk of DGF compared with Celsior in three RCTs and HTK in two RCTs. There was limited data regarding other comparisons and outcomes. The choice of preservation solution has an effect on the incidence of DGF, which might, in turn, affect long-term outcomes. Both UW and HTK have lower rates of DGF than Eurocollins. There is no difference in the incidence of DGF with the use of Celsior, HTK and UW. These findings are supported by registry data.

Quality of life is reduced in obese dogs but improves after successful weight loss.

Obesity is thought to affect quality of life, but limited objective data exist to support this supposition. The current study aim was to use a questionnaire to determine health-related quality of life (HRQOL) both before and after weight loss, in obese client-owned dogs. Fifty obese dogs were included, and represented a variety of breeds and genders. Prior to weight loss, owners were asked to complete a validated standardised questionnaire to determine HRQOL. Thirty of the dogs successfully completed their weight loss programme and reached target, and owners then completed a follow-up questionnaire. The completed questionnaire responses were transformed to scores corresponding to each of four factors (vitality, emotional disturbance, anxiety and pain), and scored on a scale of 0-6. Changes in the scores were used to explore the sensitivity of the questionnaire, and scores were correlated with responses to direct questions about quality of life and pain, as well as weight loss. Dogs that failed to complete their weight loss programme had lower vitality and higher emotional disturbance scores than those successfully losing weight (P=0.03 for both). In the 30 dogs that completed, weight loss led to an increased vitality score (P<0.001), and decreased scores for both emotional disturbance (P<0.001) and pain (P<0.001). However, there was no change in anxiety (P=0.09). The change in vitality score was positively associated with percentage weight loss (r(P)=0.43, P=0.02) and percentage body fat loss (r(P)=0.39, P=0.03). These results indicate demonstrable improvement in HRQOL for obese dogs that successfully lose weight.

Effects of weight loss in obese cats on biochemical analytes related to inflammation and glucose homeostasis.

The aim of the current study was to measure circulating metabolic and inflammation-related biochemical analytes in obese cats before and after weight loss. Thirty-seven overweight neutered cats were studied, median body weight 6.85 kg (range, 4.70 to 10.30 kg), representing a range of ages and both sexes. An individualized weight-loss program was devised for each cat and monitored until completion. Body fat mass was determined by dual-energy x-ray absorptiometry, whereas plasma concentrations of acute-phase proteins (APPs; eg, haptoglobin and serum amyloid A), hormones (eg, insulin, IGF-1, and adiponectin), and enzymes (eg, butyrylcholinesterase and paraoxonase type 1 [PON-1]) associated with inflammation and metabolic compounds (eg, glucose) were also measured. No significant changes were found in APPs after weight loss (P > 0.3), but significant increases in plasma adiponectin (P = 0.021) and IGF-1 (P = 0.036) were seen, whereas insulin (P < 0.001) and homeostasis model assessment (P = 0.005) decreased significantly. Plasma concentrations before weight loss of PON-1 (P = 0.004), adiponectin (P = 0.02), and IGF-1 (P = 0.048) were less in cats that failed to complete weight loss than cats that were successful, whereas glucose concentration was greater. Finally, multivariable linear regression analysis showed that lean tissue loss during weight management was associated with percentage weight loss (greater weight loss, greater lean tissue loss; R = 0.71, P < 0.001) and plasma adiponectin concentration before weight loss (lesser adiponectin, more lean tissue loss; R = -0.52, P = 0.023). In conclusion, various metabolic abnormalities occur in feline obesity, and these can be linked to outcomes of weight-loss programs. The changes that occur with weight loss suggest an improved metabolic status.

Long-term follow-up after weight management in obese dogs: the role of diet in preventing regain.

Regain after weight loss is widely reported in humans, but there is little information on this phenomenon in dogs. The current study aim was to determine long-term success of a weight loss regime and those factors linked with regain. Thirty-three obese dogs, that had successfully lost weight, were included, all enrolled between December 2004 and May 2009. After weight loss, dogs were switched to a maintenance regime and follow-up weight checks were performed periodically. A review of cases that had completed their weight programme was held during the summer of 2010 and a follow-up check was subsequently conducted, where dogs were reweighed and information was collected on current feeding practices. Median duration of follow-up was 640 days (119-1828 days). Fourteen dogs (42%) maintained weight, 3 (9%) lost >5% additional weight, and 16 (48%) gained >5% weight. Dogs fed a purpose-formulated weight loss diet regained less weight than those switched onto a standard maintenance diet (P=0.0016). Energy intake at the time of follow-up was significantly higher in those dogs fed a standard maintenance diet, compared with those that had remained on a purpose-formulated weight loss diet (P=0.017). These results suggest that weight regain occurs in about half of dogs after successful weight loss. Long-term use of a purpose-formulated weight management diet can significantly limit regain in the follow-up period, likely by limiting food intake.

Reprinted article "Exercise training versus angioplasty for stable claudication. Long and medium term results of a prospective, randomised trial".

OBJECTIVES: To compare percutaneous transluminal angioplsty (PTA) against exercise training in the treatment of stable claudication. DESIGN: Prospective, randomised trial. MATERIALS: Fifty-six patients with unilateral, stable, lower limb claudication assessed prior to randomisation, at 3 monthly intervals for 15 months, and at approximately 6 years follow-up. Thirty-seven patients were available for long term review. OUTCOME MEASURES: Ankle/brachial pressure index (ABPI), treadmill claudication and maximum walking distances, percentage fall in ankle systolic pressure after exercise. RESULTS: Significant increases were seen in ABPI in the patients treated with PTA at all assessment to 15 months. However in terms of improved walking performance, the most significant changes in claudication and maximum walking distance were seen in the exercise training group. At long term follow-up, there was no significant difference between the groups. Subgroup analysis by angiographic site of disease showed greater functional improvement in those patients with disease confined to the superficial femoral artery treated by exercise training. The overall prognosis for the whole group of patients was benign, with only two (4%) undergoing amputation. CONCLUSIONS: Exercise training confers a greater improvement in claudication and maximum walking distance than PTA, especially in patients with disease confined to the superficial femoral artery.

11-Hydroxy-ß-steroid dehydrogenase gene expression in canine adipose tissue and adipocytes: stimulation by lipopolysaccharide and tumor necrosis factor α.

The enzyme 11ß-hydroxysteroid dehydrogenase 1 (11ß-HSD-1) is expressed in a number of tissues in rodents and humans and is responsible for the reactivation of inert cortisone into cortisol. Its gene expression and activity are increased in white adipose tissue (WAT) from obese humans and may contribute to the adverse metabolic consequences of obesity and the metabolic syndrome. The extent to which 11ß-HSD-1 contributes to adipose tissue function in dogs is unknown; the aim of the present study was to examine 11ß-HSD-1 gene expression and its regulation by proinflammatory and anti-inflammatory agents in canine adipocytes. Real-time PCR was used to examine the expression of 11ß-HSD-1 in canine adipose tissue and canine adipocytes differentiated in culture. The mRNA encoding 11ß-HSD-1 was identified in all the major WAT depots in dogs and also in liver, kidney, and spleen. Quantification by real-time PCR showed that 11ß-HSD-1 mRNA was least in perirenal and falciform depots and greatest in subcutaneous, omental, and gonadal depots. Greater expression was seen in the omental depot in female than in male dogs (P=0.05). Gene expression for 11ß-HSD-1 was also seen in adipocytes, from both subcutaneous and visceral depots, differentiated in culture; expression was evident throughout differentiation but was generally greatest in preadipocytes and during early differentiation, declining as cells progressed to maturity. The inflammatory mediators lipopolysaccharide and tumor necrosis factor α had a main stimulatory effect on 11ß-HSD-1 gene expression in canine subcutaneous adipocytes, but IL-6 had no significant effect. Treatment with dexamethasone resulted in a significant time- and dose-dependent increase in 11ß-HSD-1 gene expression, with greatest effects seen at 24 h (2 nM: approximately 4-fold; 20 nM: approximately 14-fold; P=0.010 for both). When subcutaneous adipocytes were treated with the peroxisome proliferator activated receptor γ agonist rosiglitazone, similar dose- and time-dependent effects were noted. However, no effects were seen when adipocytes from the gonadal WAT depot were treated with rosiglitazone. The induction of 11ß-HSD-1 expression, by the pro-inflammatory cytokine tumor necrosis factor α and by lipopolysaccharide may have implications for the pathogenesis of obesity and its associated diseases in the dog.

The effects of increasing water content to reduce the energy density of the diet on body mass changes following caloric restriction in domestic cats.

Caloric restriction induces body mass loss that is often regained when restriction ends. This study aimed to determine if dietary energy density modulates the extent of post-restriction body mass regain. Water (20% wt:wt) was added to a standard dry commercially available feline diet. Twenty-seven domestic short-haired cats underwent a 20% caloric restriction on this diet. Following restriction, cats were offered the same dry diet ad libitum either without additional water or with 40% added water, therefore maintaining macronutrient composition whilst manipulating energy density. Despite no significant difference in energy intake during ad libitum consumption, post-restriction body mass regain was greater on the high energy dense (0% hydrated), compared to the low energy dense (40% hydrated) diet. The same protocol was repeated with a separate cohort of 19 cats with additional measures of physical activity, gut transit time and energy digestibility. Activity levels on the low energy dense diet were significantly higher than in cats on the high energy dense diet (p=0.030) and were similar to those recorded during caloric restriction. These results suggest that body mass gain following caloric restriction is ameliorated, and physical activity enhanced, by feeding a diet which is low in energy density due to the addition of 40% water.

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.

Improvement in insulin resistance and reduction in plasma inflammatory adipokines after weight loss in obese dogs.

Obesity is now a major disease of dogs, predisposing to numerous disorders including diabetes mellitus. Adipocytes are active endocrine cells, and human obesity is characterized by derangements in inflammatory adipokine production. However, it is unclear as to whether similar changes occur in dogs. The purpose of the current study was to assess insulin sensitivity and inflammatory adipokine profiles in dogs with naturally occurring obesity and to investigate the effect of subsequent weight loss. Twenty-six overweight dogs were studied, representing a range of breeds and both sexes. All dogs underwent a weight loss program involving diet and exercise. Body fat mass was measured by dual-energy x-ray absorptiometry; plasma concentrations of insulin, glucose, and a panel of inflammatory adipokines (including acute-phase proteins, cytokines, and chemokines) were also analyzed. Body fat mass before weight loss was positively correlated with both plasma insulin concentrations (Kendall tau=0.30, P=0.044) and insulin:glucose ratio (Kendall tau=0.36, P=0.022), and both decreased after weight loss (P=0.0037 and 0.0063, respectively). Weight loss also led to notable decreases in plasma tumor necrosis factor-alpha (TNF-alpha), haptoglobin, and C-reactive protein concentrations (P<0.05 for all), suggesting improvement of a subclinical inflammatory state associated with obesity. This study has demonstrated that in obese dogs, insulin resistance correlates with degree of adiposity, and weight loss improves insulin sensitivity. Concurrent decreases in TNF-alpha and adipose tissue mass suggest that in dogs, as in humans, this adipokine may be implicated in the insulin resistance of obesity.

Use of starting condition score to estimate changes in body weight and composition during weight loss in obese dogs.

Prior to starting a weight loss programme, target weight (TW) is often estimated, using starting body condition score (BCS). The current study assessed how well such estimates perform in clinical practice. Information on body weight, BCS and body composition was assessed before and after weight loss in 28 obese, client-owned dogs. Median decrease in starting weight per BCS unit was 10% (5-15%), with no significant difference between dogs losing moderate (1-2 BCS points) or marked (3-4 BCS points) amounts of weight (P=0.627). Mean decrease in body fat per BCS unit change was 5% (3-9%). A model based on a change of 10% of starting weight per unit of BCS above ideal (5/9) most closely estimated actual TW, but marked variability was seen. Therefore, although such calculations may provide a guide to final TW in obese dogs, they can either over- or under-estimate the appropriate end point of weight loss.