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Summary: Background: The hyperglycaemic clamp has been used for measurement of insulin sensitivity (IS) but not for measurement of β‐cell response in the horse. However, the repeatability of this test has not been reported for horses. Objectives: To determine the repeatability and reliability of measures for IS and β‐cell response to glucose using the hyperglycaemic clamp in horses. Study design: Repeated measures, longitudinal study. Methods: Six healthy Standardbred mares underwent a 120‐min hyperglycaemic clamp on two occasions with a 10‐day washout period. Indices of repeatability and reliability were calculated from measures of IS and β‐cell response to glucose derived from each hyperglycaemic clamp. Results: Measures of β‐cell response to glucose, including area under the insulin response curve in the time interval 0–120 min and during steady state (60–120 min), as well as the mean insulin concentration during steady state had coefficient of variations (CV) of 9.5, 10.5 and 9.3 respectively and intraclass correlation coefficients (ICC) of 0.93, 0.93 and 0.95 respectively. The measure of glucose disposal (M) had lower CV (12.4) and ICC (0.71) compared to measure of IS (M/I‐index; CV of 17.4 and ICC of 0.89). Main limitations: The study was conducted in a small number of horses. Conclusions: The hyperglycaemic clamp is a diagnostic method for assessing β‐cell response to intravenous glucose with high repeatability and reliability. Insulin sensitivity can be determined with the same test but the repeatability for these measurements is lower compared to the measurements for β‐cell response. [ABSTRACT FROM AUTHOR]

Background: Decreasing hyperinsulinemia is crucial in preventing laminitis in insulin dysregulated (ID) horses. Complementary pharmacological treatments that efficiently decrease postprandial hyperinsulinemia in ID horses are needed., Objectives: Compare short-term effects of canagliflozin vs placebo on glucose and insulin responses to an oral sugar test (OST) as well as the effects on body weight and triglyceride concentrations in horses with ID., Animals: Sixteen privately-owned ID horses., Methods: A single-center, randomized, double-blind, placebo-controlled, parallel design study. The horses were randomized (ratio 1:1) to either once daily PO treatment with 0.6 mg/kg canagliflozin or placebo. The study consisted of an initial 3-day period for obtaining baseline data, a 3-week double-blind treatment period at home, and a 3-day follow-up period similar to the initial baseline period but with continued double-blind treatment. Horses were subjected to an 8-sample OST in the morning of the third day on both visits., Results: Maximal geometric least square (LS) mean insulin concentration (95% confidence interval [CI]) during the OST decreased after 3 weeks of canagliflozin treatment compared with placebo (83.2; 55.4-125.0 vs 215.2; 143.2-323.2 μIU/mL). The geometric LS mean insulin response (insulin AUC 0-180 ) for canagliflozin-treated horses was >66% lower compared with placebo. Least square mean body weight decreased by 11.1 (4-18.1) kg and LS mean triglyceride concentrations increased by 0.99 (0.47-1.5) mmol/L with canagliflozin treatment., Conclusions and Clinical Importance: Canagliflozin is a promising drug for treatment of ID horses that requires future studies., (© 2023 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Overweight in dogs is an increasing problem, with a prevalence of about 30% in Sweden. To prevent the negative health effects of overweight, it is important to identify and treat canine overweight. Dog owners are essential for such interventions. The aim of this study was to evaluate dog owners' perceptions of various canine body compositions via indirect assessment based on photos and direct assessment of their own dogs. A second aim was to evaluate the effect of a standardized practical education for dog owners on body condition score (BCS) assessment of their own dogs. The 9-point BCS scale was used, and two study samples were recruited: one was a survey sample where 564 dog owners assessed the BCS of dogs using photos, and one sample was a separate clinical sample where 82 dogs were assessed by their owners and by veterinary health care personnel. The initial BCS assessment by the dog owners in the clinical sample (mean ± SD) was significantly lower (4.6 ± 1.0) than the BCS assessed by the veterinary health care personnel (5.2 ± 1.1), but the owners improved significantly after receiving the standardized education (5.1 ± 1.0) (both p < 0.0001) and performed as accurately as the veterinary health care personnel ( p = 0.99). The results should be verified in the broader dog owner population based on a randomized selection of participants. "Weight blindness", defined here as an underassessment of normal-weight dogs and an inability to identify overweight dogs, is likely to have a negative impact on canine overweight prevalence. Deeper knowledge about dog owners' perceptions can inform the development of new strategies to help prevent and manage canine overweight, whereof standardized practical education on BCS assessment is shown here to be one example.

Background: The gut microbiota and its metabolic end-products act in close collaboration with the nutrient metabolism of the animal. A relationship between excess adiposity and alterations in gut microbiota composition has been identified in humans and rodents, but data are scarce for overweight dogs. This study compared composition and temporal variations of gut microbiota in healthy lean and spontaneously overweight dogs. The analysis was based on three individual fresh faeces samples from each dog during a 10-day period. Twenty-seven healthy and intact male Labrador retriever dogs were included, 12 of which were classified as lean (body condition score (BCS) 4-5 on a 9-point scale) and 15 as overweight (BCS 6-8). Gut microbiota was analysed by Illumina sequencing of the V3-V4 region of the 16S rRNA gene., Results: Lean and overweight groups of dogs were not separated by principal coordinate analysis (PCoA), analysis of similarity (one-way ANOSIM, P = 0.99) or species indicator analysis (IndVal) using operational taxonomic units (OTU) data. Gut microbial taxa at phylum, family or genus level did not differ between lean and overweight dogs in mixed-model repeated measures analyses. Short-term stability, evaluated by similarity index, did not differ between lean and overweight dogs over the 10-day period. Pooled Firmicutes/Bacteroidetes (F/B) ratio was 3.1 ± 3.7 in overweight dogs and 2.1 ± 1.2 in lean dogs (P = 0.83). Individual dogs, irrespective of body condition (lean or overweight), displayed variation in mean alpha diversity (Chao-1 index range 122-245, Shannon index range 2.6-3.6) and mean similarity index (range 44-85%)., Conclusions: Healthy lean and spontaneously overweight Labrador retriever dogs had comparable gut microbiota composition and short-term stability over a 10-day sampling period. There were no alterations in microbial diversity or in relative abundance of specific taxa at phylum, family or genus level in overweight compared to lean dogs. Our findings suggest that there are few detectable differences in gut microbiota composition between healthy spontaneously overweight and lean dogs by the current method. Future application of metagenomic or metabolomic techniques could be used to investigate microbial genes or microbial end-products that may differ even when microbiota compositional analyses fail to detect a significant difference between lean and overweight dogs., (© 2022. The Author(s).)

Background: Obesity is associated with insulin resistance, vascular dysfunction and altered cortisol metabolism both in humans and in horses., Objectives: Evaluate the effect of weight gain induced by a haylage diet low in nonstructural carbohydrates (NSC) on insulin sensitivity, blood pressure and serum cortisol concentrations., Study Design: In vivo experiment., Methods: Nine adult Standardbred mares fed a fat supplemented haylage diet at 250% of the horses' daily metabolisable energy requirements for 22 weeks. Horses were then turned out on pasture for 4 weeks. Insulin sensitivity (SI CLAMP ) was measured before and after weight gain and after 4 weeks of pasture using the euglycemic hyperinsulinaemic clamp (EHC) method. Body condition score (BCS), blood pressure and serum cortisol were monitored throughout the study. All data were analysed using the linear mixed model procedure. Values of P < 0.05 were considered as statistically different., Results: All horses became obese during the weight gain period (BCS> 7). Mean arterial blood pressure (MAP) increased during the weight gain period and was significantly higher than initial values at the end of the weight gain period (78 ± 3 mm Hg vs 92 ± 3 mmHg). MAP remained increased on pasture (93 ± 3 mmHg). SI CLAMP was unaffected by weight gain 0.9 ± 0.1 vs 1.0 ± 0.1 ([mg/kg/min × 10 3 ]/[µIU/mL × mmol/L])) but improved after pasture (1.6 ± 0.1 ([mg/kg/min × 10 3 ]/ [mU/L]). Serum cortisol concentrations increased during the weight gain period (80 ± 9 nmol/L vs 112 ± 9 nmol/L) and remained increased during pasture., Main Limitations: Limited number of horses and no control group., Conclusions: Obesity was associated with a linear increase in blood pressure and an increase in serum cortisol that was not associated with insulin sensitivity., (© 2020 EVJ Ltd.)

Background: The prevalence of overweight and obesity is increasing in companion dogs, but little is known of these conditions in show dogs. This study assessed body condition score (BCS) of show dogs of six selected popular breeds at a major Swedish dog show event and examined the association between BCS and performance in competition., Results: At one of Sweden's largest dog shows, BCS of 120 dogs of six different breeds was assessed by trained animal healthcare personnel, using a 9-point BCS scale with conditional cut-off for overweight set to BCS ≥ 6. Prevalence of overweight in the cohort was 32% but all overweight dogs except one displayed only slight overweight (BCS 6) and no dog was assessed as obese (BCS 8-9). Prevalence of overweight differed significantly between breeds (P < 0.0001) with Labrador retrievers, Golden retrievers and French bulldogs showing the highest mean BCS (5.6-5.7) and highest prevalence of overweight (50-67%). Lean and overweight dogs received awards and higher show awards (certificates) to the same extent, and no significant association between slight overweight and performance in competition was found., Conclusions: Prevalence of overweight in Swedish show dogs was relatively high and in the same range as in the Swedish dog population as a whole. Dog owners, breeders and judges should be made aware of canine obesity problems and trained in BCS assessment, to better prevent canine overweight and associated health risks. This is particularly important for retriever and brachycephalic breeds, which showed high prevalence of slight overweight and have breed-specific health problems exacerbated by overweight. Owners and breeders of traditionally sturdy dog breeds should be informed that overweight dogs do not outperform lean dogs in competition.

Background: Proxies are mathematical calculations based on fasting glucose and/or insulin concentrations developed to allow prediction of insulin sensitivity (IS) and β-cell response. These proxies have not been evaluated in horses with insulin dysregulation. The first objective of this study was to evaluate how fasting insulin (FI) and proxies for IS (1/Insulin, reciprocal of the square root of insulin (RISQI) and the quantitative insulin sensitivity check index (QUICKI)) and β-cell response (the modified insulin-to-glucose ratio (MIRG) and the homeostatic model assessment of β-cell function (HOMA-β)) were correlated to measures of IS (M index) using the euglycemic hyperinsulinemic clamp (EHC) in horses with insulin resistance (IR) and normal IS. A second objective was to evaluate the repeatability of FI and proxies in horses based on sampling on consecutive days. The last objective was to investigate the most appropriate cut-off value for the proxies and FI., Results: Thirty-four horses were categorized as IR and 26 as IS based on the M index. The proxies and FI had coefficients of variation (CVs) ≤ 25.3 % and very good reliability (intraclass correlation coefficients ≥ 0.89). All proxies and FI were good predictors of the M index (r = 0.76-0.85; P < 0.001). The proxies for IS had a positive linear relationship with the M index whereas proxies for β-cell response and FI had an inverse relationship with the M index. Cut-off values to distinguish horses with IR from horses with normal IS based on the M index were established for all proxies and FI using receiver operating characteristic curves, with sensitivity between 79 % and 91 % and specificity between 85 % and 96 %. The cut-off values to predict IR were < 0.32 (RISQI), < 0.33 (QUICKI) and > 9.5 µIU/mL for FI., Conclusions: All proxies and FI provided repeatable estimates of horses' IS. However, there is no advantage of using proxies instead of FI to estimate IR in the horse. Due to the heteroscedasticity of the data, proxies and FI in general are more suitable for epidemiological studies and larger clinical studies than as a diagnostic tool for measurement of IR in individual horses.

Obesity in dogs is an increasing problem and better knowledge of the metabolism of overweight dogs is needed. Identification of molecular changes related to overweight may lead to new methods to improve obesity prevention and treatment. The aim of the study was firstly to investigate whether Nuclear Magnetic Resonance (NMR) based metabolomics could be used to differentiate postprandial from fasting urine in dogs, and secondly to investigate whether metabolite profiles differ between lean and overweight dogs in fasting and postprandial urine, respectively. Twenty-eight healthy intact male Labrador Retrievers were included, 12 of which were classified as lean (body condition score (BCS) 4-5 on a 9-point scale) and 16 as overweight (BCS 6-8). After overnight fasting, a voided morning urine sample was collected. Dogs were then fed a high-fat mixed meal and postprandial urine was collected after 3 hours. Metabolic profiles were generated using NMR and 45 metabolites identified from the spectral data were evaluated using multivariate data analysis. The results revealed that fasting and postprandial urine differed in relative metabolite concentration (partial least-squares discriminant analysis (PLS-DA) 1 comp: R2Y = 0.4, Q2Y = 0.32; cross-validated ANOVA: P = 0.00006). Univariate analyses of discriminant metabolites showed that taurine and citrate concentrations were elevated in postprandial urine, while allantoin concentration had decreased. Interestingly, lean and overweight dogs differed in terms of relative metabolite concentrations in postprandial urine (PLS-DA 1 comp: R2Y = 0.5, Q2Y = 0.36, cross-validated ANOVA: P = 0.005) but not in fasting urine. Overweight dogs had lower postprandial taurine and a trend of higher allantoin concentrations compared with lean dogs. These findings demonstrate that metabolomics can differentiate 3-hour postprandial urine from fasting urine in dogs, and that postprandial urine metabolites may be more useful than fasting metabolites for identification of metabolic alterations linked to overweight. The lowered urinary taurine concentration in overweight dogs could indicate alterations in lipid metabolism and merits further investigation.

Background: An oral sugar test (OST) using Karo ® Light Corn Syrup has been developed in the USA as a field test for the assessment of insulin dysregulation in horses but the syrup is not available in Scandinavian grocery stores. The aim of the study was to compare the results of a modified OST between horses with equine metabolic syndrome (EMS) and healthy horses using a Scandinavian commercially available glucose syrup (Dansukker glykossirap). In addition, the effect of breed and the repeatability of the test were evaluated. In the present study, clinically healthy horses (7 Shetland ponies, 8 Icelandic horses, 8 Standardbred horses) and 20 horses of various breeds with EMS underwent the modified OST test. The Icelandic horses and Shetland ponies underwent the OST twice. Insulin and glucose data from the OST were used to calculate peak insulin concentration (Peak INS ), time to peak insulin concentration (T-peak INS ), area under the curve for insulin (AUC INS ) and glucose (AUC GLU ) as well as whole body insulin sensitivity index (ISI COMP )., Results: Compared to the healthy group, the EMS group had 6-7 times higher geometric mean for Peak INS and AUC INS and 8 times lower geometric mean for ISI COMP . The EMS group had a delayed T-peak INS compared to the healthy group. There was no effect of breed in the group of healthy horses on Peak INS , T-peak INS , AUC INS , AUC GLU and ISI COMP . Coefficient of variation for repeated tests was 19.8, 19.0 and 17.6 % for Peak INS , AUC INS and ISI COMP respectively., Conclusions: The results of the present study demonstrate that the modified OST appears to be a practical and useful diagnostic tool for assessment of insulin dysregulation in the horse. However, to make it possible to establish the most appropriate sampling interval and to evaluate the accuracy of the modified OST, further studies in horses with a variable degree of insulin resistance are needed, where results from the modified OST are compared with quantitative measurements for IS.