Evaluation of raw meat diets on macronutrient digestibility, fecal output, microbial presence, and general health status in domestic dogs.

Raw meat-based diets (RMBDs) are typically fed to exotic carnivores managed in zoological institutions and are gaining in popularity as dietary options for pet dogs. Current research themes of RMBDs for zoo carnivores have centered around utilization in exotic felid species with a paucity of data obtained from exotic canids. In addition, current research themes of RMBDs for domestic dogs have centered around microbial contamination. Conducting nutrition-related research in exotic canids is often limited because animals are group-housed, preventing accurate individual feed intake and fecal output collection. Due to functional and anatomical similarities between digestive systems of domestic dogs with their wild counterparts, dogs may serve as an experimental model for nutrition studies for certain exotic canid species. The overall objectives of this research were to evaluate four commercially manufactured RMBDs formulated for zoological carnivores using domestic dogs as a model for exotic canids and to evaluate microbial risk to humans and canine health implications beyond digestibility. We hypothesize all RMBDs: 1.) evaluated would be highly digestible in domestic dogs, 2.) microbial risk to humans would be low, and 3.) there would be no adverse implications on canine health as a result of feeding RMBDs. Overall, nutrients in RMBDs were highly digested by domestic dogs and diets did not result in clinical signs of gastrointestinal upset/distress. Further, RMBDs did not negatively influence general health status in dogs as measured by serum chemistry, electrolytes, complete blood count (CBC), and histology of gastrointestinal tract and associated tissues. Ussing chamber evaluation of intestinal integrity and barrier function indicated possible benefit of feeding RMBDs to dogs. Our first aim was to evaluate diet composition, apparent total tract macronutrient and energy digestibility, feed intake, fecal output, and microbial presence of four commercially-manufactured RMBDs for zoological carnivores fed to domestic dogs. Diets varied in protein source including horse (Horse), pork (Pork) and two beef-based diets (Beef 1 and Beef 2). Our results indicated that diets were comparable in nutrient and energy composition and apparent total tract digestibility when fed to domestic dogs (n=4). Treatment nutrient concentrations ranged for dry matter (DM) (32.2 – 36.2%), organic matter (OM) (91.1 – 94.9%), crude protein (CP) (50.3 – 61.7%), fat (25.1 – 38.3%), and gross energy (GE) (5.8 – 6.4 kcal/g). Digestibility of nutrients and energy ranged from 83.3 – 92.4%, 88.4 – 95.3%, 93.8 – 97.7%, 94.9 – 98.2%, and 91.3 – 95.5% for DM, OM, CP, fat, and energy, respectively. Fecal chemical composition, specifically fat on a dry matter basis (DMB), differed markedly for dogs consuming one of the beef diets (Beef 2). Dogs fed Beef 2 had greater (P\u3c0.05) concentrations of fat in feces (21.5%) compared to 2.9, 6.1, and 6.3% for dogs fed Horse, Pork, and Beef 1, respectively. Despite the large fecal fat concentration, dogs fed Beef 2 diet had greater (P\u3c0.05) digestibility of DM (92.4%), OM (95.3%), CP (97.7%), and GE (95.5%) but lesser (P\u3c0.05) digestibility of fat (94.9%) compared with all other diets evaluated. Additional digestibility differences were few. Feces were scored using the following scale: 1 = very hard, dry feces to 7 = watery diarrhea (NestlÃÂé Purina). Fecal scores were lower (P\u3c0.05) when dogs were fed Horse (1.2) and Beef 2 (1.9) diets compared to Pork (2.7) and Beef 1 (3.1) diets. Detection of Salmonella spp. in diet and saliva samples was non-existent and only 5.6% (n=2/36) of fecal samples were Salmonella spp. positive. Detection of generic E. coli was determined in 12.5% (n=2/16) and 5.6% (n=2/36) of diet and saliva samples, respectively. Our second aim was to compare gastrointestinal histology, intestinal transepithelial electrical resistance (TER), and intestinal macromolecule permeability between domestic dogs fed commercial extruded- versus RMBDs. No differences were observed in gastrointestinal histology between dietary treatment groups. TER and macromolecule permeability data were highly variable and statistical analyses were not performed due to low sample size. Numerical increases in apparent permeability coefficient (Papp) were observed in extruded-fed dogs indicating increased macromolecule permeability that is suggestive of decreased intestinal integrity and barrier function. These results indicate potential improvements in intestinal barrier function when dogs were fed RMBDs using a novel technique; however, further evaluation should be considered with a larger sample size. This research demonstrates that RMBDs varying in protein source and ingredients can be effectively utilized by domestic dogs and potentially exotic canids. While these experiments evaluated four commercial products manufactured for exotic carnivores in domestic dogs, further research should evaluate direct comparisons between digestive efficiencies of domestic dogs compared to various exotic canid species. Our research also indicates that human exposure to pathogens associated with feeding RMBDs to dogs is possible but risk appears low based on presence of measured microbes. Additionally, this research indicates value in the use of gastrointestinal histology and Ussing chamber evaluation of intestinal integrity and barrier function as novel approaches for determining health effects beyond nutrient digestibility of various diets in domestic dogs

Preclinical Modeling of Metabolic Syndrome to Study the Pleiotropic Effects of Novel Antidiabetic Therapy Independent of Obesity

Background and Purpose: Cardiovascular-kidney-metabolic health reflects the interactions between metabolic risk factors, chronic kidney disease, and the cardiovascular system. A growing body of literature suggests that metabolic syndrome (MetS) in individuals of normal weight is associated with a high prevalence of cardiovascular diseases and an increased mortality. The aim of this study was to establish a non-invasive preclinical model of MetS in support of future research focusing on the effects of novel antidiabetic therapies beyond glucose reduction, independent of obesity. Experimental Approach: Eighteen healthy adult Beagle dogs were fed an isocaloric Western diet (WD) for ten weeks. Biospecimens were collected at baseline (BAS1) and after ten weeks of WD feeding (BAS2) for measurement of blood pressure (BP), serum chemistry, lipoprotein profiling, blood glucose, glucagon, insulin secretion, NT-proBNP, angiotensins, oxidative stress biomarkers, serum, urine, and fecal metabolomics. Differences between BAS1and BAS2 were analyzed using non-parametric Wilcoxon signed-rank testing. Key Results: The isocaloric WD model induced significant variations in several markers of MetS, including elevated BP, increased glucose concentrations, and reduced HDL-cholesterol. It also caused an increase in circulating NT-proBNP levels, a decrease in serum bicarbonate, and significant changes in general metabolism, lipids, and biogenic amines. Conclusions and Implications: Short-term, isocaloric feeding with a WD in dogs replicated key biological features of MetS while also causing low-grade metabolic acidosis and elevating natriuretic peptides. These findings support the use of the WD canine model for studying the metabolic effects of new antidiabetic therapies independent of obesity.This is a preprint from Mochel, Jonathan P., Jessica L. Ward, Thomas Blondel, Debosmita Kundu, Maria M. Merodio, Claudine Zemirline, Emilie Guillot et al. "Preclinical Modeling of Metabolic Syndrome to Study the Pleiotropic Effects of Novel Antidiabetic Therapy Independent of Obesity." (2024). doi: https://doi.org/10.21203/rs.3.rs-4235628/v1. Copyright 2024, The Authors. This work is licensed under a Creative Commons Attribution 4.0 International License

Dose–response of benazepril on biomarkers of the classical and alternative pathways of the renin–angiotensin–aldosterone system in dogs

Angiotensin-converting enzyme inhibitors (ACEI) such as benazepril are commonly prescribed in both humans and dogs with heart disease to mitigate the renin–angiotensin–aldosterone system (RAAS); however, the dose-dependent effects of benazepril on comprehensive RAAS components remain unknown. In this study, nine purpose-bred healthy dogs received three different dosages of oral benazepril (0.125 mg/kg, 0.25 mg/kg, or 0.5 mg/kg) in a randomized crossover design following induction of RAAS activation by consuming a low-sodium diet. Blood samples were collected at serial time intervals after benazepril dosing to measure plasma benazeprilat (active metabolite of benazepril) and serum RAAS biomarkers. Blood pressure and echocardiogram were performed at baseline and after each benazepril administration. Time-weighted averages for RAAS biomarkers for 12 h post-dose and hemodynamic variables were compared between dosing groups using Wilcoxon rank-sum testing. Compared to the lowest dosage of benazepril (0.125 mg/kg), the highest dosage (0.5 mg/kg) resulted in lower time-weighted average values of angiotensin (Ang) II (− 38%, P = 0.004), Ang1-5 (− 53%, P = 0.001), ACE-S (surrogate for ACE activity; − 59%, P = 0.0002), and ALT-S (surrogate for alternative RAAS activity; − 22%, P = 0.004), and higher values of AngI (+ 78%, P = 0.014) and PRA-S (surrogate for plasma renin activity; + 58%, P = 0.040). There were no relevant differences between dosing groups for blood pressure or echocardiographic variables. Knowledge of dose-dependent alterations in biomarkers of the classical and alternative RAAS pathways could help inform clinical trials for dosage optimization in both dogs and humans.This article is published as Sotillo, Samantha, Jessica L. Ward, Emilie Guillot, Oliver Domenig, Lingnan Yuan, Joseph S. Smith, Vojtech Gabriel, Chelsea A. Iennarella-Servantez, and Jonathan P. Mochel. "Dose–response of benazepril on biomarkers of the classical and alternative pathways of the renin–angiotensin–aldosterone system in dogs." Scientific Reports 13, no. 1 (2023): 2684. DOI: 10.1038/s41598-023-29771-x. Copyright 2023 The Author(s). Attribution 4.0 International (CC BY 4.0). Posted with permission.

Canine Intestinal Organoids as a Novel In Vitro Model of Intestinal Drug Permeability: A Proof-of-Concept Study

A key component of efforts to identify the biological and drug-specific aspects that contribute to therapeutic failure or unexpected exposure-associated toxicity is the study of drug-intestinal barrier interactions. While methods supporting such assessments are widely described for human therapeutics, there is relatively little information available for similar evaluation in support of veterinary pharmaceuticals. There is, therefore, a critical need to develop novel approaches for evaluating drug-gut interactions in veterinary medicine. Three-dimensional (3D) organoids can address these difficulties in a reasonably affordable system that circumvents the need for more invasive in vivo assays in live animals. However, a first step in the development of such systems is understanding organoid interactions in a 2D monolayer. Given the importance of orally administered medications for meeting the therapeutic need of companion animals, we demonstrate growth conditions under which canine colonoid-derived intestinal epithelial cells survive, mature, and differentiate into confluent cell systems with high monolayer integrity. We further examine the applicability of this canine colonoid-derived 2D model to assess the permeability of three structurally diverse, passively absorbed β-blockers (e.g., propranolol, metoprolol, and atenolol). Both absorptive and secretive apparent permeability (Papp) of these drugs at two different pH conditions were evaluated in canine colonoid-derived monolayers and were compared with that of Caco-2 cells. This proof-of-concept study provides promising preliminary results with regard to the utility of canine-derived organoid monolayers for species-specific assessments of therapeutic drug passive permeability.This is a pre-print of the article Sahoo, Dipak Kumar, Marilyn Martinez, Kimberly Dao, Vojtech Gabriel, Christopher Zdyrski, Albert E. Jergens, Todd Atherly et al. "Canine Intestinal Organoids as a Novel In Vitro Model of Intestinal Drug Permeability: A Proof-of-Concept Study." (2023): 2023040101. DOI: 10.20944/preprints202304.0101.v1. Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted

Canine Intestinal Organoids as a Novel In Vitro Model of Intestinal Drug Permeability: A Proof-of-Concept Study

A key component of efforts to identify the biological and drug-specific aspects contributing to therapeutic failure or unexpected exposure-associated toxicity is the study of drug–intestinal barrier interactions. While methods supporting such assessments are widely described for human therapeutics, relatively little information is available for similar evaluations in support of veterinary pharmaceuticals. There is, therefore, a critical need to develop novel approaches for evaluating drug–gut interactions in veterinary medicine. Three-dimensional (3D) organoids can address these difficulties in a reasonably affordable system that circumvents the need for more invasive in vivo assays in live animals. However, a first step in developing such systems is understanding organoid interactions in a 2D monolayer. Given the importance of orally administered medications for meeting the therapeutic need of companion animals, we demonstrate growth conditions under which canine-colonoid-derived intestinal epithelial cells survive, mature, and differentiate into confluent cell systems with high monolayer integrity. We further examine the applicability of this canine-colonoid-derived 2D model to assess the permeability of three structurally diverse, passively absorbed β-blockers (e.g., propranolol, metoprolol, and atenolol). Both the absorptive and secretive apparent permeability (Papp) of these drugs at two different pH conditions were evaluated in canine-colonoid-derived monolayers and compared with that of Caco-2 cells. This proof-of-concept study provides promising preliminary results with regard to the utility of canine-derived organoid monolayers for species-specific assessments of therapeutic drug passive permeability

Synbiotic-IgY Therapy Modulates the Mucosal Microbiome and Inflammatory Indices in Dogs with Chronic Inflammatory Enteropathy: A Randomized, Double-Blind, Placebo-Controlled Study

Chronic inflammatory enteropathy (CE) is a common cause of persistent gastrointestinal signs and intestinal inflammation in dogs. Since evidence links dysbiosis to mucosal inflammation, probiotics, prebiotics, or their combination (synbiotics) may reduce intestinal inflammation and ameliorate dysbiosis in affected dogs. This study’s aim was to investigate the effects of the synbiotic-IgY supplement on clinical signs, inflammatory indices, and mucosal microbiota in dogs with CE. Dogs with CE were enrolled in a randomized prospective trial. Twenty-four client-owned dogs were fed a hydrolyzed diet and administered supplement or placebo (diet) for 6 weeks. Dogs were evaluated at diagnosis and 2- and 6-week post-treatment. Outcome measures included clinical activity, endoscopic and histologic scores, inflammatory markers (fecal calprotectin, C-reactive protein), and composition of the mucosal microbiota via FISH. Eleven supplement- and nine placebo-treated dogs completed the trial. After 6 weeks of therapy, clinical activity and endoscopic scores decreased in both groups. Compared to placebo-treated dogs, dogs administered supplement showed decreased calprotectin at 2-week post-treatment, decreased CRP at 2- and 6-week post-treatment increased mucosal Clostridia and Bacteroides and decreased Enterobacteriaceae in colonic biopsies at trial completion. Results suggest a beneficial effect of diet and supplements on host responses and mucosal microbiota in dogs with CE.This article is published as Sahoo, Dipak Kumar, Karin Allenspach, Jonathan P. Mochel, Valerie Parker, Adam Joseph Rudinsky, Jenessa A. Winston, Agnes Bourgois-Mochel et al. "Synbiotic-IgY Therapy Modulates the Mucosal Microbiome and Inflammatory Indices in Dogs with Chronic Inflammatory Enteropathy: A Randomized, Double-Blind, Placebo-Controlled Study." Veterinary Sciences 10, no. 1 (2023): 25. DOI: 10.3390/vetsci10010025. Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted

A Preclinical Model of Obesity-Independent Metabolic Syndrome for Studying the Effects of Novel Antidiabetic Therapy Beyond Glycemic Control

Accumulating data from several large, placebo-controlled studies suggests that sodium-glucose transporter 2 (SGLT-2) inhibitors and glucagon-like peptide 1 receptor (GLP-1) receptor agonists offer therapeutic benefits in the management of cardiovascular diseases, regardless of the patient's diabetic status. In addition to their effects on glucose excretion, SGLT2-inhibitors have a positive impact on systemic metabolism by reducing inflammation and oxidative stress, shifting metabolism towards ketone body production, and suppressing glycation end-product signaling. The aim of this study was to establish a non-invasive preclinical model of metabolic syndrome (MetS) to investigate the effects of novel antidiabetic therapies beyond glucose reduction, independent of obesity. Eighteen healthy adult Beagle dogs were fed isocalorically a Western diet (WD) adjusted from parameters of the National Health and Nutrition Examination Survey for ten weeks. Blood samples were collected at baseline (BAS1) when dogs were fed their regular diet, and then again after ten weeks of WD feeding (BAS2) for measurement of blood count and serum chemistry, lipoprotein profiling, fasting blood glucose, glucagon, insulin, NT-proBNP, BUN, creatinine, angiotensins and oxidative stress biomarkers. Blood pressure (BP) was measured at BAS1 and BAS2 using Doppler. Serum, urine and fecal metabolomics were derived by mass spectrometry to assess general metabolism, complex lipids and biogenic amines. Differences between BAS1 and BAS2 were analyzed using non-parametric Wilcoxon signed rank testing with continuity correction, as appropriate. Body weight changes did not exceed 13% after ten weeks of feeding with the WD. The isocaloric WD model induced significant variations in several markers of MetS, including (1) elevated BP, (2) increased fasting glucose levels, and (3) reduced HDL-cholesterol. It also triggered a significant decrease in circulating insulin, as well as an increase in circulating NT-proBNP levels and a decrease in serum bicarbonate levels. Marked and significant changes in overall metabolism, lipids, and biogenic amines were finally reported at BAS2. Short-term, isocaloric feeding with a WD in dogs replicates key biological features of MetS, while also causing low-grade metabolic acidosis and elevating natriuretic peptides. These findings support the use of the WD canine model for studying the metabolic effects of new antidiabetic therapies independent of obesity.This is a preprint from Mochel, Jonathan P., Jessica L. Ward, Thomas Blondel, Debosmita Kundu, Maria M. Merodio, Claudine Zemirline, Emilie Guillot et al. "A Preclinical Model of Obesity-Independent Metabolic Syndrome for Studying the Effects of Novel Antidiabetic Therapy Beyond Glycemic Control." (2023). doi: https://doi.org/10.21203/rs.3.rs-3569600/v1. Copyright The Authors 2023. This work is licensed under a Creative Commons Attribution 4.0 International License

Synbiotic-IgY Therapy Modulates the Mucosal Microbiome and Inflammatory Indices in Dogs with Chronic Inflammatory Enteropathy: A Randomized, Double-Blind, Placebo-Controlled Study

Chronic inflammatory enteropathy (CE) is a common cause of persistent gastrointestinal signs and intestinal inflammation in dogs. Since evidence links dysbiosis to mucosal inflammation, probiotics, prebiotics, or their combination (synbiotics) may reduce intestinal inflammation and ameliorate dysbiosis in affected dogs. This study’s aim was to investigate the effects of the synbiotic-IgY supplement on clinical signs, inflammatory indices, and mucosal microbiota in dogs with CE. Dogs with CE were enrolled in a randomized prospective trial. Twenty-four client-owned dogs were fed a hydrolyzed diet and administered supplement or placebo (diet) for 6 weeks. Dogs were evaluated at diagnosis and 2- and 6-week post-treatment. Outcome measures included clinical activity, endoscopic and histologic scores, inflammatory markers (fecal calprotectin, C-reactive protein), and composition of the mucosal microbiota via FISH. Eleven supplement- and nine placebo-treated dogs completed the trial. After 6 weeks of therapy, clinical activity and endoscopic scores decreased in both groups. Compared to placebo-treated dogs, dogs administered supplement showed decreased calprotectin at 2-week post-treatment, decreased CRP at 2- and 6-week post-treatment increased mucosal Clostridia and Bacteroides and decreased Enterobacteriaceae in colonic biopsies at trial completion. Results suggest a beneficial effect of diet and supplements on host responses and mucosal microbiota in dogs with CE

Preclinical modeling of metabolic syndrome to study the pleiotropic effects of novel antidiabetic therapy independent of obesity

International audienceCardiovascular-kidney-metabolic health reflects the interactions between metabolic risk factors, chronic kidney disease, and the cardiovascular system. A growing body of literature suggests that metabolic syndrome (MetS) in individuals of normal weight is associated with a high prevalence of cardiovascular diseases and an increased mortality. The aim of this study was to establish a noninvasive preclinical model of MetS in support of future research focusing on the effects of novel antidiabetic therapies beyond glucose reduction, independent of obesity. Eighteen healthy adult Beagle dogs were fed an isocaloric Western diet (WD) for ten weeks. Biospecimens were collected at baseline (BAS1) and after ten weeks of WD feeding (BAS2) for measurement of blood pressure (BP), serum chemistry, lipoprotein profiling, blood glucose, glucagon, insulin secretion, NT-proBNP, angiotensins, oxidative stress biomarkers, serum, urine, and fecal metabolomics. Differences between BAS1 and BAS2 were analyzed using non-parametric Wilcoxon signed-rank testing. The isocaloric WD model induced significant variations in several markers of MetS, including elevated BP, increased glucose concentrations, and reduced HDL-cholesterol. It also caused an increase in circulating NT-proBNP levels, a decrease in serum bicarbonate, and significant changes in general metabolism, lipids, and biogenic amines. Short-term, isocaloric feeding with a WD in dogs replicated key biological features of MetS while also causing low-grade metabolic acidosis and elevating natriuretic peptides. These findings support the use of the WD canine model for studying the metabolic effects of new antidiabetic therapies independent of obesity.</div