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Background: Clinicopathological findings and their association with the outcome and development of laminitis in horses with acute diarrhoea has not been investigated in a multicentre study across different geographic regions., Objectives: Describe and compare clinicopathologic findings of diarrhoeic horses between different geographic regions, survival rates and factors associated with non-survival and laminitis., Study Design: Multicentre retrospective case series., Methods: Information from horses with acute diarrhoea presenting to participating institutions between 2016 and 2020 was collected, and clinicopathological data were compared between surviving and non-surviving horses and horses that did and did not develop laminitis. Survival rates and seasonal and geographic differences were also investigated., Results: One thousand four hundred thirty-eight horses from 26 participating institutions from 4 continents were included; 76% survived to discharge with no differences identified between geographic regions. The survival proportion of horses with SIRS and creatinine concentrations > 159 μmol/L was 55% (154/279) compared with 81% (358/437) for those with SIRS and creatinine concentrations < 159 μmol/L (p < 0.001). The survival proportion of horses with SIRS that had an L-lactate concentration > 2.8 mmol/L was 59% (175/298) compared with 81% (240/296) in horses with SIRS and L-lactate concentration < 2.8 mmol/L (p < 0.001). The proportion of horses that developed laminitis was lower in Europe (4%, 19/479) compared with North America (8%, 52/619), Australia (8%, 12/138) and Latin America (11%, 16/146) (p < 0.05). More horses developed laminitis in the summer (46%, 39/85) compared with winter (18%, 15/85), spring (18%, 15/85) and fall (19%, 16/85) (p < 0.01). Horses with laminitis had greater odds of non-survival than those without laminitis (OR: 3.73, 95% CI: 2.47-5.65)., Main Limitations: Not all variables were available for all horses due to the retrospective nature., Conclusions: Clinicopathological findings in horses with acute diarrhoea and their association with survival are similar across geographic regions. However, developing laminitis secondary to diarrhoea is less common in Europe. In addition, factors associated with non-survival were indicative of disease severity and subsequent cardiovascular compromise., (© 2023 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Background: An international description of the diagnostic approaches used in different institutions to diagnose acute equine diarrhoea and the pathogens detected is lacking., Objectives: To describe the diagnostic approach, aetiological agents, outcome, and development of laminitis for diarrhoeic horses worldwide., Study Design: Multicentre retrospective case series., Methods: Information from horses with acute diarrhoea presenting to participating institutions between 2016 and 2020, including diagnostic approaches, pathogens detected and their associations with outcomes, were compared between institutions or geographic regions., Results: One thousand four hundred and thirty-eight horses from 26 participating institutions from 4 continents were included. Overall, aetiological testing was limited (44% for Salmonella spp., 42% for Neorickettsia risticii [only North America], 40% for Clostridiodes difficile, and 29% for ECoV); however, 13% (81/633) of horses tested positive for Salmonella, 13% (35/262) for N. risticii, 9% (37/422) for ECoV, and 5% (27/578) for C. difficile. C. difficile positive cases had greater odds of non-survival than horses negative for C. difficile (OR: 2.69, 95%CI: 1.23-5.91). In addition, horses that were positive for N. risticii had greater odds of developing laminitis than negative horses (OR: 2.76, 95%CI: 1.12-6.81; p = 0.029)., Main Limitations: Due to the study's retrospective nature, there are missing data., Conclusions: This study highlighted limited diagnostic investigations in cases of acute equine diarrhoea. Detection rates of pathogens are similar to previous reports. Non-survival and development of laminitis are related to certain detected pathogens., (© 2023 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Equine veterinarians frequently treat patients in non-climate-controlled (i.e., hospitalized) settings. In colder environments, intravenous (IV) fluid administration can contribute to patient hypothermia. The objective of this study was to evaluate three IV fluid warming mechanisms to determine their effect on fluid outflow temperatures at ambient temperatures of 21-22°C and 3.5°C. In this study, fluid outflow temperatures were measured using three warming mechanisms: (1) pre-warmed fluids at 42°C, (2) an in-line warming device placed 163 cm away from the Luer-lock fluid line adaptor (location 1) on the fluid line, and (3) an in-line warming device placed 88 cm away from the Luer-lock fluid line adaptor (location 2) on the fluid line. These warming mechanisms were compared to outflow temperatures measured using no warming mechanism at ambient temperatures of 21-22°C and 3.5°C with flow rates of ∼12 L/hour (gravity flow bolus) and 999 mL/hour. All outflow temperatures were measured with a thermistor. At ∼12L/hour, the use of pre-warmed fluids increased outflow temperatures at both ambient temperatures of 21-22°C and 3.5°C ambient temperatures and an in-line warming device placed at location 1 significantly increased outflow temperatures in 3.5 ° C ambient temperatures. At 999 mL/hour, use of pre-warmed fluids or an in-line warming device, placed at either location, increased outflow temperatures at ambient temperatures of 21°C or 3.5°C., Competing Interests: Declaration of competing interest This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Equine rotavirus is one of the most common causes of infectious diarrhea in foals. Although the infection itself is self-limiting, the resulting diarrhea is due to multiple mechanisms and can be severe, requiring supportive care including fluid and electrolyte support. Prompt diagnosis is important for treatment and biosecurity decisions and can be achieved by several means. Prevention, while imperfect, currently relies on vaccination of pregnant mares before parturition, ingestion of adequate colostrum from vaccinated mares and biosecurity measures., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Little is known about the acquisition and use of equine analgesic drugs by horse owners in the United States (US)., Objectives: To determine factors associated with possession of analgesic drugs by horse owners in the US or with analgesic drug acquisition from sources noncompliant with a valid veterinarian-client-patient (VCPR) relationship., Study Design: Cross-sectional survey., Methods: An internet-based questionnaire included items related to experiences with horses and equine analgesic drugs. Factors associated with possession of ≥5 types of analgesic drugs and with the acquisition of drugs from VCPR noncompliant sources were analysed using logistic regression., Results: Responses from 389 US horse owners indicated that 96% have access to at least one type of equine analgesic medication and most are confident in their drug administration skills. Horse owners with ≥5 types of analgesic drugs were more likely to have managed >20 horses in their life (odds ratio [OR] = 3.1, 95% confidence interval [CI] = 1.7-5.6), have medical insurance for some horses (OR = 4.2, CI = 2.3-7.7), and have veterinary or human medical training (OR = 2.2, CI = 1.2-4.1) and were less likely to have a primary care veterinarian requiring >30 minutes travel time (OR = 0.5, CI = 0.3-0.9). Horse owners who obtained drugs through VCPR noncompliant sources were likely to be male (OR = 5.6, CI = 1.6-19.4), ≤40 years of age (OR = 2.0, CI = 1.2-3.2), and reside in the South or West regions of the US (OR = 2.4, CI = 1.4-4.0)., Main Limitations: Possible distribution, self-selection, response, and recall biases as a result of convenience sampling methodology., Conclusions: Discussion between veterinarians and horse owners regarding available analgesic drugs and owners' competence in administering those drugs may improve veterinary care recommendations and owner compliance., (© 2022 EVJ Ltd.)

Background: Understanding factors influencing assessment of pain in horses will facilitate communication between veterinarians and horse owners., Objectives: To compare estimates of pain experienced by horses as provided by veterinarians and horse owners and to determine factors associated with individuals who perceive horses to be experiencing extreme pain or minimal pain., Study Design: Cross-sectional study., Methods: Internet-based questionnaires for horse owners and veterinarians included items related to recognition of pain in horses, estimated degree of pain experienced by horses, and demographic information. Variables associated with perception of a high or low degree of pain were investigated using logistic regression analyses., Results: Final data sets included responses from 553 horse owners and 263 veterinarians. Pain scores varied widely and differences in median scores from horse owners and veterinarians were small. Horse owners providing high pain ratings were more likely to have <10 horses (odds ratio [OR] = 2.0, 95% CI = 1.1-3.5) and to not have a college degree (OR = 1.5, 95% CI = 1.0-2.2). Those providing low pain ratings were less likely to own <10 horses (OR = 0.6, 95% confidence interval [CI] = 0.4-0.9). Veterinarians providing high pain ratings were more likely to be employed in a mixed animal practice (OR = 2.8, 95% CI = 1.3-5.9) and to lack board-certification in a veterinary specialty (OR = 2.1, 95% CI = 1.1-4.2). Veterinarians providing low pain ratings were more likely to be male (OR = 2.4, 95% CI = 1.3-4.2)., Main Limitations: The respondent population may be biased because of the method of questionnaire distribution and associated sampling bias. Respondents were primarily from the United States., Conclusions: Assessments of the degree of pain horses are experiencing vary widely among horse owners and equine veterinarians., (© 2022 EVJ Ltd.)

Objectives: In humans, serum zonulin, a biomarker of intestinal permeability, correlates with underlying enteropathies and has potential application as a therapeutic target. The aim of this study was to evaluate serum zonulin as a biomarker for canine chronic enteropathy., Materials and Methods: Prospective enrolment of twenty-one client-owned dogs with at least 1 of the following gastrointestinal (GI) signs for at least 3 weeks duration: anorexia, hyporexia, dysrexia, vomiting, weight loss or diarrhea. 21 control dogs, age and breed matched, were also enrolled. Dogs with gastrointestinal signs were diagnosed with chronic enteropathy based on a complete blood count, serum chemistry, specific canine pancreatic lipase, cobalamin, resting cortisol, abdominal ultrasound and gastrointestinal endoscopy with histopathology. Enrolled control dogs had an unremarkable physical examination, complete blood count, serum chemistry and no clinical signs of gastrointestinal disease. Dogs were ineligible if antibiotics or immunosuppressive medications were administered within 1 month of enrolment. Blood samples were analysed using a commercial canine serum zonulin quantitative ELISA., Results: Dogs with chronic enteropathies had median serum zonulin values of 0.28 ng/mL (interquartile range: 0.04-2.59), while control dogs of 0.27 ng/mL (0.05-3.67). There was no significant difference in canine serum zonulin levels between these populations. The estimated difference in the median concentrations was -0.01 ng/mL (95% CI: -0.23 to 0.89)., Clinical Significance: In this study, using a commercial canine zonulin ELISA, serum zonulin levels did not differentiate between dogs with chronic enteropathies and control dogs., (© 2022 British Small Animal Veterinary Association.)

We investigated the effects of season and geographic location on detection of nucleic acids of potential enteric pathogens (PEPs) or their toxins (PEP-Ts) in feces of horses ≥6-mo-old in the United States. Results of 3,343 equine diarrhea PCR panels submitted to Idexx Laboratories for horses >6-mo-old were reviewed. Submission months were grouped into 4 seasons, and states were grouped into 4 geographic regions. Logistic regression was performed to assess effects of season and region on detection rates of PEPs and PEP-Ts. Agresti-Coull CIs were determined. Detection rate of Salmonella enterica was higher in the South in summer compared to all other regions, and was also higher in the South in fall compared to the Midwest and Northeast. The Neorickettsia risticii detection rate was lower during summer in the West and higher in fall in the Midwest. Detection of Cryptosporidium spp. was lower during spring, summer, and winter in the West. Differences were not identified for detection rates of Clostridioides difficile , Clostridium perfringens , Lawsonia intracellularis , Rhodococcus equi , equine rotavirus, and equine coronavirus. Overall, our data support seasonal and regional differences in detection rates of S. enterica , N. risticii , and Cryptosporidium spp. in horses ≥6-mo-old in the United States.

In a recent issue of the Lancet, the prevalence of Inflammatory Bowel Disease (IBD) was estimated at 7 million worldwide. Overall, the burden of IBD is rising globally, with direct and indirect healthcare costs ranging between $14.6 and $31.6 billion in the U.S. alone in 2014. There is currently no cure for IBD, and up to 40% of patients do not respond to medical therapy. Although the exact determinants of the disease pathophysiology remain unknown, the prevailing hypothesis involves complex interplay among host genetics, the intestinal microenvironment (primarily bacteria and dietary constituents), and the mucosal immune system. Importantly, multiple chronic diseases leading to high morbidity and mortality in modern western societies, including type II diabetes, IBD and colorectal cancer, have epidemiologically been linked to the consumption of high-calorie, low-fiber, high monosaccharide, and high-fat diets (HFD). More specifically, data from our laboratory and others have shown that repeated consumption of HFD triggers dysbiotic changes of the gut microbiome concomitant with a state of chronic intestinal inflammation and increased intestinal permeability. However, progress in our understanding of the effect of dietary interventions on IBD pathogenesis has been hampered by a lack of relevant animal models. Additionally, current in vitro cell culture systems are unable to emulate the in vivo interplay between the gut microbiome and the intestinal epithelium in a realistic and translatable way. There remains, therefore, a critical need to develop translatable in vitro and in vivo models that faithfully recapitulate human gut-specific physiological functions to facilitate detailed mechanistic studies on the impact of dietary interventions on gut homeostasis. While the study of murine models has been pivotal in advancing genetic and cellular discoveries, these animal systems often lack key clinical signs and temporal pathological changes representative of IBD. Specifically, some limitations of the mouse model are associated with the use of genetic knockouts to induce immune deficiency and disease. This is vastly different from the natural course of IBD developing in immunologically competent hosts, as is the case in humans and dogs. Noteworthily, abundant literature suggests that canine and human IBD share common clinical and molecular features, such that preclinical studies in dogs with naturally occurring IBD present an opportunity to further our understanding on disease pathogenesis and streamline the development of new therapeutic strategies. Using a stepwise approach, in vitro mechanistic studies investigating the contribution of dietary interventions to chronic intestinal inflammation and "gut leakiness" could be performed in intestinal organoids and organoid derived monolayers. The biologic potential of organoids stems from the method's ability to harness hard-wired cellular programming such that the complexity of the disease background can be reflected more accurately. Likewise, the effect of therapeutic drug candidates could be evaluated in organoids prior to longitudinal studies in dog and human patients with IBD. In this review, we will discuss the value (and limitations) of intestinal organoids derived from a spontaneous animal disease model of IBD (i.e., the dog), and how it can heighten understanding of the interplay between dietary interventions, the gut microbiota and intestinal inflammation. We will also review how intestinal organoids could be used to streamline the preclinical development of therapeutic drug candidates for IBD patients and their best four-legged friends., Competing Interests: Authors KA, AEJ and JPM are co-founders of 3D Health Solutions, Inc. Author EG is employed by Ceva Sante Animale and acts as a consultant of 3D Health Solutions, Inc. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Kopper, Iennarella-Servantez, Jergens, Sahoo, Guillot, Bourgois-Mochel, Martinez, Allenspach and Mochel.)

Probiotics are defined as live microorganisms that confer a health benefit to the host when administered in adequate amounts, therefore the presence of viable microorganisms is essential. Previous studies reported inconsistencies when comparing contents of probiotics marketed for use in animals with label claims. However, to the author's knowledge the variability of the same product between different lots has yet to be evaluated. The objective of this observational study was to evaluate the content and inter-lot variability of commercial equine probiotic products using culture dependent and independent techniques. Eleven probiotics marketed for use in horses were evaluated for microbial content using culture-dependent and independent techniques. The content was then compared to microorganisms listed and quantities on the label of the probiotic. Statistical analyses were performed using a Kruskal-Wallis test. None of the 11 probiotics met their label claim. Nine of the 11 did not have statistically significant inter-lot variability. Several products lacked microorganisms listed on the label based on both culture and polymerase chain reaction (PCR) analyses., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Rates of detecting ≥1 potential enteric pathogens (PEP) or toxins (PEP-T) in feces, blood, or both of horses ≥6 months of age with enteric disease and impact of multiple detections on outcome of horses with colitis has not been reported., Objective: To determine detection rates of PEP/PEP-T in feces, blood, or both of horses with enteric disease and effect of detecting multiple agents on outcome of horses with colitis., Animals: Thirty-seven hundred fifty-three fecal samples submitted to IDEXX Laboratories and 239 fecal and blood samples submitted to Michigan State University's Veterinary Diagnostic Laboratory (MSUVDL)., Methods: Retrospective evaluation of PEP/PEP-T testing results was performed to determine rates of detection of 1 or more PEP/PEP-T. Impact of detecting multiple agents on outcome was assessed in 239 horses hospitalized for colitis., Results: One or more PEP/PEP-T was detected in 1175/3753 (31.3%) and 145/239 (60.7%) of samples submitted to IDEXX Laboratories and MSUVDL, respectively. In a hospitalized cohort, survival to discharge was lower (76%) in horses with 1 agent, compared to horses with either no (88%) or multiple (89%) agents. There was no difference (P = .78) in days of hospitalization between horses with 0 (1-17), 1 (1-33), and > 1 positive (1-20) result. There was no difference in cost of hospitalization (P = .25) between horses with 0 ($2357, $1110-15 553), 1 ($2742, $788-11 005), and >1 positive ($2560, $1091-10 895) result., Conclusions and Clinical Importance: Detection rates of PEP/PEP-T in horses with colitis vary with cohorts and tests performed. Detection of more than 1 PEP or PEP-T did not affect outcome., (© 2021 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Probiotics, by definition, are live micro-organisms and should remain viable when they reach the intended site of action which is typically the cecum and/or colon. In humans, probiotics often need enteric protection to survive transit through the proximal gastrointestinal (GI) tract. Typically, equine probiotics do not advertise enteric protection and to the author's knowledge the viability of equine probiotics after exposure to the proximal GI tract has not been evaluated. The objective of this study was to evaluate the effect of an in vitro simulation of the equine proximal GI tract on probiotic viability. We hypothesized that the simulated proximal GI tract would adversely effect microbial viability and that the adverse effects would be partially ameliorated by increasing the gastric pH to 4. A total of 11 products were evaluated of which six had at least one micro-organism that was adversely effected by exposure to the proximal GI tract and four of which had at least one micro-organism that was adversely affected when the gastric pH was increased to 4.0. Results from this study indicate that some micro-organisms in equine probiotics do not appear to be adversely affected by exposure to the equine proximal GI tract., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The objective of this study was to determine if transferable antimicrobial resistance (AMR) genes are present in commercial animal probiotics. DNA was extracted from 50 probiotics, tested for the presence of bacterial DNA, and analyzed by polymerase chain reaction (PCR) for the presence of 8 transferrable AMR genes, including tetracycline, erythromycin, aminoglycoside, sulfonamide, and trimethoprim. Samples that were positive by PCR were confirmed by genome sequencing. Forty-seven (94%) products contained bacterial DNA. Of these, 97% contained at least 1 AMR gene, and 82% contained 2 or more. These results indicate that further evaluation of the risk for transmission of these AMR genes may be warranted., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Hospitalized horses are at risk for colic due to several factors, all of which may reduce voluntary water intake (VWI) further contributing to the development of colic during hospitalization. Our objectives were to determine if using flavored water (sweet feed, peppermint, or apple-flavored electrolyte) increases VWI of hospitalized horses and to determine if horses consumed more flavored water versus plain water. We hypothesized that (1) in hospitalized horses the availability of flavored water results in more VWI than the availability of unflavored water and that (2) average intake of flavored water is larger for flavored versus unflavored within the experimental (flavored) group. Four groups of hospitalized horses (n = 10/group) were recruited. All horses were provided two buckets of water. Control horses were provided two buckets of plain water. The other three groups were provided one bucket of plain water and one bucket of flavored water (sweet feed, peppermint, or a commercial apple-flavored electrolyte). The total and the flavor-specific water consumed was recorded during a 72-hour period. There was weak evidence to suggest that the use of flavored water increases median total water intake of hospitalized horses by a factor of 1.76 [95% CI: 0.98 to 3.11] for sweet feed (P = .05) and 1.85 [95% CI: 1.03 to 3.33] for peppermint (P = .04). The results strongly supported that horses consumed more sweet feed-flavored water (27.0 mL/kg/day [95% CI: 14.6 to 39.3] more water) compared with plain water (P = .0001)., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Fecal microbiota transplant (FMT), a technique used to restore normal intestinal microbial communities, has been successful in treating humans with Clostridioides difficile colitis. Subsequently, FMT is being used in veterinary patients with suspected intestinal dysbiosis. Unfortunately, little data are available regarding best practices for FMT in horses. The objective of this study was to evaluate the effects of storing manure prepared for equine FMT (MP-FMT) at -20°C for up to 4 weeks and passage through a simulated proximal gastrointestinal (GI) tract on the viability of MP-FMT. The results of this study indicate that storage at -20°C for greater than 1 week and exposure to conditions consistent with the proximal GI tract significantly decreased viability of the microbial population, with gram-negative enteric bacteria most significantly impacted. This preliminary evaluation indicates that further work is necessary to determine best practices to preserve the viability MP-FMT in horses., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The nematode Trichuris muris has been shown to interact with specific enteric bacteria, but its effects on the composition of its host's microbial community are not fully understood. We hypothesized that Trichuris muris -infected mice would have altered colon microbiota as compared with uninfected mice. Colon histopathology and microbial community structure and composition were examined in mouse models of colitis (C3BirTLR4 -/- IL10 -/- and C3H/HeJ TLR4 -/- IL10 +/+ mice) with and without T. muris infection, in uninfected C3BirIL10 -/- mice with and without spontaneous colitis, and in normal C3H/ HeJ mice. T. muris -infected mice developed colon lesions that were more severe than those seen in IL10-deficient mice. Ap- proximately 80% of infected IL10 -/- mice had colon neutrophilic exudates, and some had extraintestinal worms and bacteria. The composition and structure of proximal colon microbiota were assessed by using terminal restriction fragment length polymorphism analysis targeting the bacterial 16S rRNA gene. Colon microbiota in C3BirIL10 -/- and C3H/HeJ mice differed both qualitatively and quantitatively. Trichuris infection significantly altered the relative abundance of individual operational taxonomic units [OTU] but not the composition (presence or absence of OTU) of colon microbiota in the 2 mouse genotypes. When C3BirIL10 -/- and C3H/HeJ mouse OTU were considered separately, Trichuris was found to affect the microbiota of C3BirIL10 -/- mice but not of C3H/HeJ mice. Even though 34 of the 75 (45%) C3BirIL10 -/- mice had spontaneous colitis, neither qualitative nor quantitative differences were detected in microbiota between colitic or noncolitic C3BirIL10 -/- mice or noncolitic C3H/HeJ mice. Therefore, Trichuris -infected mice developed distinct microbial communities that were influenced by host background genes; these alterations cannot be attributed solely to colonic inflammation.

Objective: Vancomycin resistant enterococci (VRE) are of significant public health concern. The identification of VRE in livestock and food has increased. The objective of this study was to determine if the transferrable vancomycin resistance genes vanA and vanB were present in probiotics marketed for use in animals that claimed to contain Enterococcus spp., Results: Of the 40 products selected, Enterococcus spp. DNA was successfully extracted from 36 products. Of these 36 products with enterococcal DNA, 2 (6%) had a PCR product consistent with vanA which was confirmed by sequencing. None of the products appeared to contain vanB.

Equine coronavirus (ECoV) is a known cause of fever, anorexia, and lethargy in adult horses. Although there are multiple reports of ECoV outbreaks, less is known about the clinical presentation of individual horses during a nonoutbreak situation. The purpose of this study was to describe the clinical presentation of horses diagnosed with ECoV infection that were not associated with an outbreak. Medical records of all horses admitted to Washington State University, Veterinary Teaching Hospital, during an 8-year period were reviewed (2010-2018). The five horses included in this study were older than 1 year of age, were diagnosed with colitis, tested positive for ECoV using real-time polymerase chain reaction, and were negative to other enteric pathogens. Interestingly, 4 of 5 horses had moderate to severe diarrhea, 3 had abnormal large colon ultrasonography, 2 had transient ventricular tachycardia and 2 had clinicopathologic evidence of liver dysfunction. ECoV should be included as a differential diagnosis for individual horses presenting with anorexia, fever, lethargy, and colitis. Early identification of ECoV cases is key to implement appropriate biosecurity measures to prevent the potential spread of this disease., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The objective of this study was to determine whether there was an association between type of colloid administered and survival of horses with enterocolitis (N = 92). A retrospective review of medical records of horses with enterocolitis treated with plasma or hetastarch (HES) between January 1, 2005 and December 31, 2011 was performed. Data collected included signalment, outcome, physical and clinicopathologic findings, and volume and type of colloid administered. Sixty-nine horses (75%) were treated with plasma and 23 horses (25%) were treated with HES. After accounting for confounding variables, horses treated with plasma (80% survival) were more likely to survive to discharge than horses treated with HES (47% survival; P = 0.041) despite similar disease severity at admission. This study provides support that use of natural colloids may be superior to treatment with synthetic colloids in horses with enterocolitis. A prospective, multi-center trial comparing outcome of critically ill equine patients treated with natural or synthetic colloids is warranted., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Background: Obtaining commercial fluids for intravenous administration (IVF) was challenging during a recent shortage. This necessitated use of custom-made non-sterile fluids for intravenous administration (JUGs) in some hospitals. There are no studies comparing outcome of horses treated with JUG versus IVF and limited information is available about adverse effects of JUGs., Hypothesis/objectives: To evaluate death, complications, blood pH, and plasma electrolyte concentrations of horses that received JUG versus IVFs., Animals: One hundred eighty-six horses that received IVFs and 37 that received JUGs., Methods: A retrospective review of medical records was performed to identify horses that received IVFs or JUGs during hospitalization. Information including survival to discharge, complications (fever [>38.5°C], jugular vein phlebitis/thrombosis, arrhythmia, or laminitis), blood pH, and plasma electrolyte concentrations were obtained., Results: There was no difference (P = .67) in survival to discharge for horses that received JUGs (78%) compared to horses that received IVFs (87%). Horses that received JUGs were more likely to develop a jugular vein complication (3 of 37 versus 1 of 186, odds ratio 17.2 [95% CI 1.9-389.8], P = .04). Horses that received JUGs were more likely to have electrolyte abnormalities consistent with hyperchloremic metabolic acidosis., Conclusion and Clinical Importance: Veterinarians using JUGs should obtain informed client consent because of a potential increased risk of jugular vein complications. Chloride content of JUGs should be considered to limit development of hyperchloremic metabolic acidosis., (© 2019 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Objective: To investigate effects of body condition on permeability of intestinal mucosa in horses., Animals: 13 horses (7 obese and 6 lean) from 8 to 15 years of age., Procedures: Body condition score was assessed, and an oral sugar test (OST) was performed to evaluate glucose and insulin dynamics. Horses were allowed a 2-week diet acclimation period and were then euthanized. Tissue samples were collected from the jejunum, ileum, cecum, pelvic flexure, right dorsal colon, and rectum. Mucosal permeability was assessed by measuring transepithelial resistance and lipopolysaccharide (LPS) flux across tissue samples mounted in Ussing chambers., Results: 5 obese horses and 1 lean horse had evidence of insulin dysregulation, whereas 1 obese and 5 lean horses had no abnormalities in results of the OST. Results for the OST were not available for 1 obese horse. Mucosal transepithelial resistance did not differ in any intestinal segment between obese and lean horses. Obese horses had a significantly higher LPS flux across jejunal mucosa, compared with results for lean horses, but there were no significant differences between obese and lean horses for other intestinal segments., Conclusions and Clinical Relevance: Obese horses may have had greater paracellular mucosal permeability of jejunal mucosa to LPS, compared with that for lean horses. This finding was consistent with data for the gastrointestinal mucosa of humans and mice and supported the hypothesis that obese horses may be at higher risk from chronic exposure to increased amounts of LPS, compared with the risk for lean horses.

Trichuris muris infected C57BL/6 mice are a frequently studied model of immune mediated resistance to helminths. Our objective was to characterize dose-dependent gastrointestinal (GI) disease and pathology due to Trichuris in C57BL/6 mice with varying degrees of IL-10 sufficiency. These mice can serve as a model for other animals (dogs, cattle) and humans where IL-10 polymorphisms have been associated with disease susceptibility and may affect susceptibility to whipworm. C57BL/6 IL-10(+/+), IL-10(+/-) and IL-10(-/-) mice were infected with T. muris (J strain) in a dose response study. T. muris produced dose-dependent disease in IL-10(-/-) mice. Ninety percent of mice receiving the high dose (75 ova) had severe disease necessitating early euthanasia, while the medium dose (50 ova) resulted in 100% early euthanasia of males/75% of females, and the low dose (25 ova) in 100% early euthanasia of males/25% of females. Having some IL-10 as in heterozygotes did not rescue all infected mice from effects of the high dose. 2/21 IL-10(-/-), 1/17 IL-10(+/-), and 0/17 IL-10(+/+) mice in the high dose group had severe peritonitis and extra-intestinal bacteria confirmed by fluorescent 16S rDNA analysis of peritoneal organ surfaces. Three of twenty one IL-10(-/-) had demonstrable extra-intestinal T. muris adults. Although free from viral pathogens, 12/21 IL-10(-/-), 6/17 IL-10(+/-), and 4/17 IL-10(+/+) infected mice had hepatitis, while control mice of all genotypes did not. Mice had evidence of inflammation of serosal surfaces of liver, spleen and GI tract even when extraintestinal Trichuris were not found. Blinded histopathology scoring revealed that even when infected IL-10(-/-) mice displayed few, if any, clinical signs, levels of gut inflammation did not vary significantly from those mice euthanized early due to severe disease. To examine whether antibiotics or corticosteroids could reverse severe disease and lesions, IL-10(-/-) mice infected with T. muris were treated with metronidazole or prednisolone prior to and throughout 40 days of infection. Mice given prednisolone had severe disease and lesions with the highest mortality rate. Mice given metronidazole had a significantly lower mortality rate than those given prednisolone, but GI lesions were of similar severity and distribution including peritonitis. Mortality was associated with extraintestinal worms and bacteria and further supported a role for enteric bacteria in this pathogenesis., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Human Campylobacter jejuni infection can result in an asymptomatic carrier state, watery or bloody diarrhea, bacteremia, meningitis, or autoimmune neurological sequelae. Infection outcomes of C57BL/6 IL-10(-/-) mice orally infected with twenty-two phylogenetically diverse C. jejuni strains were evaluated to correlate colonization and disease phenotypes with genetic composition of the strains. Variation between strains was observed in colonization, timing of development of clinical signs, and occurrence of enteric lesions. Five pathotypes of C. jejuni in C57BL/6 IL-10(-/-) mice were delineated: little or no colonization, colonization without disease, colonization with enteritis, colonization with hemorrhagic enteritis, and colonization with neurological signs with or without enteritis. Virulence gene content of ten sequenced strains was compared in silico; virulence gene content of twelve additional strains was compared using a C. jejuni pan-genome microarray. Neither total nor virulence gene content predicted pathotype; nor was pathotype correlated with multilocus sequence type. Each strain was unique with regard to absences of known virulence-related loci and/or possession of point mutations and indels, including phase variation, in virulence-related genes. An experiment in C. jejuni 11168-infected germ-free mice showed that expression levels of ninety open reading frames (ORFs) were significantly up- or down-regulated in the mouse cecum at least two-fold compared to in vitro growth. Genomic content of these ninety C. jejuni 11168 ORFs was significantly correlated with the capacity to colonize and cause enteritis in C57BL/6 IL-10(-/-) mice. Differences in gene expression levels and patterns are thus an important determinant of pathotype in C. jejuni strains in this mouse model., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Murine immunological responses to experimental infection with Trichuris muris and the effects of the resident microbiota on these responses are of increasing interest. For these studies, accurate dose delivery and improved sterilization of inocula are essential to prevent co-infection with unknown contaminants. We found that washing T. muris eggs with antibiotics may not be sufficient for sterilization of inocula. However, washing eggs in 6.25% hypochlorite/bleach eliminated bacteria and fungi, as determined by culture and PCR, did not harm viable T. muris eggs and reduced the number of non-viable eggs in the inocula. A hatching assay and propidium iodide staining method were developed and found to increase the accuracy for assessing T. muris egg viability prior to infection for rapid dose evaluation. In addition, metal gavage feeding needles increased the accuracy and precision of the dose delivered to the mice compared to flexible rubber tubes. These methods will improve experimental Trichuris studies by decreasing the variability in outcome due to unintended carryover of adherent microorganisms and unrecognized variation in inocula.

We hypothesized that particular genetic backgrounds enhance rates of colonization, increase severity of enteritis, and allow for extraintestinal spread when inbred IL-10(-/-) mice are infected with pathogenic C. jejuni. Campylobacter jejuni stably colonized C57BL/6 and NOD mice, while congenic strains lacking IL-10 developed typhlocolitis following colonization that mimicked human campylobacteriosis. However, IL-10 deficiency alone was not necessary for the presence of C. jejuni in extraintestinal sites. C3H/HeJ tlr4(-/-) mice that specifically express the Cdcs1 allele showed colonization and limited extraintestinal spread without enteritis implicating this interval in the clinical presentation of C. jejuni infection. Furthermore, when the IL-10 gene is inactivated as in C3Bir tlr4(-/-) IL-10(-/-) mice, enteritis and intensive extraintestinal spread were observed, suggesting that clinical presentations of C. jejuni infection are controlled by a complex interplay of factors. These data demonstrate that lack of IL-10 had a greater effect on C. jejuni induced colitis than other immune elements such as TLR4 (C3H/HeJ, C3Bir IL-10(-/-)), MHC H-2g7, diabetogenic genes, and CTLA-4 (NOD) and that host genetic background is in part responsible for disease phenotype. C3Bir IL-10(-/-) mice where Cdcs1 impairs gut barrier function provide a new murine model of C. jejuni and can serve as surrogates for immunocompromised patients with extraintestinal spread.

We used terminal restriction fragment polymorphism (T-RFLP) analysis to assess (1) stability of the fecal microbiota in dogs living in environments characterized by varying degrees of exposure to factors that might alter the microbiota and (2) changes in the microbiota associated with acute episodes of diarrhea. Results showed that the healthy canine GI tract harbors potential enteric pathogens. Dogs living in an environment providing minimal exposure to factors that might alter the microbiota had similar microbiotas; the microbiotas of dogs kept in more variable environments were more variable. Substantial changes in the microbiota occurred during diarrheic episodes, including increased levels of Clostridium perfringens, Enterococcus faecalis, and Enterococcus faecium. When diet and medications of a dog having a previously stable microbiota were changed repeatedly, the microbiota also changed repeatedly. Temporal trend analysis showed directional changes in the microbiota after perturbation, a return to the starting condition, and then fluctuating changes over time.