Fecal shedding of Clostridioides difficile in calves in Sao Paulo state, Brazil.

OBJECTIVE: This study aimed to evaluate the fecal shedding of C. difficile in calves on farms in Sao Paulo State, Brazil. MATERIALS AND METHODS: Fecal samples (n = 300) were collected from diarrheic (n = 78) and nondiarrheic (n = 222) calves less than 60 days of age from 20 farms. Fecal samples were inoculated into enrichment broth supplemented with taurocholate and cultured under anaerobic conditions. Colonies suspected to be C. difficile were harvested for DNA extraction and then multiplex PCR for the detection of genes encoding toxins A and B and binary toxins. All toxigenic isolates were ribotyped and tested for antimicrobial susceptibility, and five selected strains were subjected to whole-genome sequencing to determine their sequence type. RESULTS AND DISCUSSION: C. difficile was isolated from 29.3 % (88/300) of the samples. All toxigenic isolates (17/88, 19.3 %) were classified as ribotypes RT046 (13/17-79.47 %, A+B+ CDT-) and RT126 (4/17 = 20.53 %, A+B+ CDT+). The sequenced strains from RT046 were classified as ST35 (Clade 1), while those from RT126 were classified as ST11 (Clade 5). No associations between the epidemiological factors in any of the groups and C. difficile isolation were observed. Most of the toxigenic isolates (16/17 = 94.41 %) were classified as multidrug-resistant. Calves can be an important source of toxigenic C. difficile strains, including multidrug-resistant isolates from ribotypes commonly observed in humans.

Fecal prevalence of Clostridium innocuum DNA in healthy horses and horses with colitis.

This study compared the prevalence of C. innocuum DNA in the feces of healthy horses and horses with acute colitis. C. innocuum was identified in 22% (15/68) of colitis cases and 18% (12/68) of healthy horses (p = 0.416).

Diagnosis of Potomac horse fever (syn. equine neorickettsiosis) in 2 foals in southwestern Ontario.

Potomac horse fever (PHF) is characterized by fever, depression, anorexia, ileus, diarrhea, and occasionally, laminitis. The disease is caused by infection with Neorickettsia risticii and/or N. findlayensis. Equids of all ages may be affected; however, the condition has not been well-characterized in foals. This report describes clinical signs, laboratory findings, and treatment of 2 foals diagnosed with PHF in southwestern Ontario. Feces submitted for an equine PCR panel tested positive for Neorickettsia spp. and were subsequently confirmed to be N. risticii (Case 1) and N. findlayensis (Case 2). Both foals recovered following hospitalization and intensive care. Key clinical message: The purpose of this report is to make veterinarians aware that foals may develop PHF. During summer (July to September), when encountering foals in endemic areas with clinical signs compatible with PHF, veterinarians should consider PHF as a diagnostic rule-out. For confirmation of the diagnosis, blood and feces should be submitted for PCR testing for Neorickettsia spp.

Diagnostic de la fièvre équine du Potomac (syn. néorickettsiose équine) chez 2 poulains dans le sud-ouest de l'Ontario. La fièvre équine du Potomac (PHF) se caractérise par de la fièvre, une dépression, de l'anorexie, un iléus, de la diarrhée et, occasionnellement, une fourbure. La maladie est causée par une infection par Neorickettsia risticii et/ou N. findlayensis. Les équidés de tous âges peuvent être atteints; cependant, cette pathologie n'a pas été bien caractérisée chez les poulains. Ce rapport décrit les signes cliniques, les résultats de laboratoire et le traitement de 2 poulains diagnostiqués avec PHF dans le sud-ouest de l'Ontario. Les matières fécales soumises à un panel PCR équin se sont révélées positives pour Neorickettsia spp. et ont ensuite été confirmées comme étant positives pour N. risticii (cas 1) et N. findlayensis (cas 2). Les deux poulains se sont rétablis après une hospitalisation et des soins intensifs.Message clinique clé :Le but de ce rapport est de sensibiliser les vétérinaires au fait que les poulains peuvent développer une PHF. Pendant l'été (juillet à septembre), lorsqu'ils rencontrent des poulains dans des zones d'endémie présentant des signes cliniques compatibles avec le PHF, les vétérinaires doivent considérer le PHF comme une exclusion diagnostique. Pour confirmer le diagnostic, du sang et des selles doivent être soumis à un test PCR pour Neorickettsia spp.(Traduit par Dr Serge Messier).

Real-Time PCR Differential Detection of Neorickettsia findlayensis and N. risticii in Cases of Potomac Horse Fever.

Potomac horse fever (PHF) is an acute and potentially fatal enterotyphlocolitis of horses with clinical signs that include anorexia, fever, diarrhea, and laminitis. Its incidence is increasing despite a commercially available vaccine. PHF is caused by Neorickettsia risticii, and the recently rediscovered and classified N. findlayensis. PHF diagnosis is currently accomplished using serology or nested PCR. However, both methods cannot distinguish the two Neorickettsia species that cause PHF. Further, the current N. risticii real-time PCR test fails to detect N. findlayensis. Thus, in this study, two Neorickettsia species-specific real-time PCR assays based on Neorickettsia ssa2 and a Neorickettsia genus-specific real-time PCR assay based on Neorickettsia 16S rRNA gene were developed. The ssa2 real-time PCR tests differentiated N. findlayensis from N. risticii in the field samples for which infection with either species had been verified using multiple other molecular tests and culture isolation, and the 16S rRNA gene real-time PCR detected both Neorickettsia species in the samples. These tests were applied to new field culture isolates from three Canadian provinces (Alberta, Quebec, Ontario) and Ohio as well as archival DNA samples from suspected PHF cases to estimate the prevalence of N. findlayensis in different geographic regions. The results suggest that N. findlayensis frequently causes PHF in horses in Alberta and Quebec. The development of these tests will allow rapid, sensitive, and specific diagnosis of horses presenting with clinical signs of PHF. These tests will also enable rapid and targeted treatment and help develop broad-spectrum vaccines for PHF.

Serum IgM antibody response to Clostridioides difficile polysaccharide PS-II vaccination in pony foals.

OBJECTIVES: Clostridioides difficile (formerly Clostridium difficile) is associated with colitis in foals and mature horses. C. difficile exposes specific phosphorylated polysaccharides (PSs), named PS-I, PS-II and PS-III. These cell-surface PSs are potential vaccine targets, especially the hexasaccharide phosphate PS-II, that has been found in all C. difficile ribotypes examined. Since we previously identified anti-PS-II circulating antibodies in horses, we postulated that vaccinating foals with PS-II may prevent colonization by C. difficile. In this study, we aim to evaluate the IgM antibody responses in foals to PS-II. METHODS: To evaluate the reactogenicity and immunogenicity of C. difficile PS-II in foals, three-to four-month-old foals were vaccinated intramuscularly three times at intervals of three weeks with 100 µg/dose (3 foals) or 500 µg/dose (3 foals) of purified PS-II antigen with aluminum hydroxide adjuvant, or with a placebo preparation (2 foals) containing adjuvant alone. RESULTS: No injection site swelling, pain or fever was observed after vaccination. Two of the three foals receiving 100 µg/dose, and three out of three foals receiving 500 µg/dose of PS-II responded with increases in serum IgM antibodies. No control foals that received the placebo had IgM responses to PS-II. There was a trend towards a higher response rate in foals receiving 500 µg PS-II one week after second vaccination when compared to control foals and towards higher concentrations of serum IgM antibodies in foals receiving 500 µg PS-II. CONCLUSIONS: No adverse reactions were observed following vaccination with PS-II in foals; Serum IgM immune responses were induced by vaccination. A polysaccharide-based vaccine for C. difficile in horses deserves further investigation.

Acute diarrhea in horses: A multicenter Canadian retrospective study (2015 to 2019).

This study describes the clinicopathological findings, diagnostic approach, treatment, and factors associated with non-survival of diarrheic horses admitted to 4 Canadian university teaching hospitals between 2015 and 2019. A total of 300 horses, ≥1-year-old, with acute diarrhea were included and represented 1.6% (300/18 481; range: 0.7 to 3%) of admissions during that period, 70% of the horses survived to discharge. Testing for enteropathogens was limited to a single fecal culture for Salmonella spp. in most cases. An enteropathogen was identified in 14% (42/300) of the horses, but in the hospital with higher testing rates enteropathogens were detected in 29% (16/55) of cases. Neorickettsia risticii was the pathogen most frequently detected (31%, 32/102). Antimicrobial drugs and plasma were administered to 57 and 8% of the cases, respectively. Laminitis occurred in 24/298 (8%) of the horses. A multivariable regression model identified an association between non-survival of diarrheic horses and colic signs, increased heart rate, packed cell volume, creatinine concentration, and decreased total protein concentration. A standardized approach for pathogen detection in diarrheic horses is not consistent among Canadian veterinary teaching hospitals, and testing for known pathogens is limited. Signs of colic, severe dehydration, endotoxemia, and hypoproteinemia are associated with non-survival of diarrheic horses.

Diarrhée aiguë chez le cheval : une étude rétrospective canadienne multicentrique (2015 à 2019). Cette étude décrit les résultats clinicopathologiques, l'approche diagnostique, le traitement et les facteurs associés à la non-survie de chevaux diarrhéiques admis dans quatre hôpitaux universitaires canadiens entre 2015 et 2019. Un total de 300 chevaux, ≥1 an, atteints de diarrhée aiguë ont été inclus et représentaient 1,6 % (300/18 481; intervalle : 0,7 à 3 %) des admissions au cours de cette période. Soixante-dix pourcents des chevaux ont survécu jusqu'à leur congé. La recherche d'agents entéropathogènes était limitée à une seule culture fécale pour Salmonella spp. dans la plupart des cas. Un agent entéropathogène a été identifié chez 14 % (42/300) des chevaux, mais à l'hôpital avec des taux de dépistage plus élevés, des agents entéropathogènes ont été détectés dans 29 % (16/55) des cas. Neorickettsia risticii était l'agent pathogène le plus fréquemment détecté (31 %, 32/102). Des médicaments antimicrobiens et du plasma ont été administrés respectivement à 57 et 8 % des cas. Une fourbure est survenue chez 24/298 (8 %) des chevaux. Un modèle de régression multivarié a identifié une association entre la non-survie des chevaux diarrhéiques et les signes de coliques, l'augmentation de la fréquence cardiaque, l'hématocrite, la concentration de créatinine et la diminution de la concentration totale de protéines. Une approche normalisée pour la détection des agents pathogènes chez les chevaux diarrhéiques n'est pas uniforme dans les hôpitaux d'enseignement vétérinaires canadiens, et les tests pour les agents pathogènes connus sont limités. Des signes de coliques, de déshydratation sévère, d'endotoxémie et d'hypoprotéinémie sont associés à la non-survie des chevaux diarrhéiques.(Traduit par Dr Serge Messier).

Development and Validation of a Three-Dimensional Printed Training Model to Teach Ultrasound-Guided Injections of the Cervical Articular Process Joints in Horses.

Intra-articular injections are routinely performed to alleviate pain and inflammation associated with osteoarthritis in horses. Intra-articular injections require accurate needle placement to optimize clinical outcomes and minimize complications. This study's objectives were to develop and validate a three-dimensional (3D) printed model of an equine cervical articular process joint to teach ultrasound-guided injections. Five identical models of an equine cervical articular process joint were 3D printed and embedded in 10% ballistic gelatin. Experts' and novices' ability to successfully insert a needle into the joint space of the model using ultrasound guidance was assessed and graded using an objective structured clinical examination (OSCE). Scores from experts and novices were compared to evaluate the construct validity of the model. Participants also answered a survey assessing the face and content validity of the model. Experts required less time (22.51 seconds) for correct needle placement into the model joint space than novices (35.96 seconds); however, this difference was not significant (p = .53). Experts' median total OSCE score (14) was significantly higher (p = .03) than novices' (12), supporting the model's construct validity. Participants agreed on the face and content validity of the model by grading all survey questions greater than 7 on a 10-point Likert-type scale. In summary, we successfully developed a 3D printed model of an equine cervical articular process joint, partially demonstrated the construct validity of the model, and proved the face and content validity of this new training tool.

Standing laparoscopic abdominal lavage using a suction-irrigation device in 2 horses with primary suppurative peritonitis.

The use of a laparoscopic suction-irrigation device in 2 standing horses for lavage of the abdomen for the treatment of primary suppurative peritonitis is reported. Two horses were presented with a 1- to 2-week history of weight loss. Abdominocentesis revealed highly elevated total nucleated cell count. Peritoneal lavage systems were placed in both horses, but complications prevented adequate lavage. Both horses underwent standing laparoscopy; the dorsal abdomen was explored and the abdomen was profusely lavaged, using a suction-irrigation device. The procedure was efficient and allowed adequate visualization of the dorsal abdomen and lavage. A successful outcome was achieved in both cases. Key clinical message: Lavage of the abdomen of horses with peritonitis can be achieved under standing sedation, using a laparoscopic technique. In appropriately selected cases, this allows for adequate visualization of the dorsal abdomen and efficacious abdominal lavage.

Lavage abdominal laparoscopique debout à l'aide d'un dispositif d'irrigation par aspiration chez deux chevaux atteints de péritonite suppurée primaire. L'utilisation d'un dispositif laparoscopique d'irrigation par aspiration pour le lavage de l'abdomen pour le traitement d'une péritonite suppurée primaire chez deux chevaux debout est rapportée. Deux chevaux ont été présentés avec une histoire de 1 à 2 semaines de perte de poids. L'abdominocentèse a révélé un nombre total de cellules nucléées très élevé. Des systèmes de lavage péritonéal ont été placés chez les deux chevaux, mais des complications ont empêché un lavage adéquat. Les deux chevaux ont subi une laparoscopie debout; l'abdomen dorsal a été exploré, et l'abdomen a été abondamment lavé à l'aide d'un dispositif d'irrigation par aspiration. La procédure était efficace et permettait une visualisation adéquate de l'abdomen dorsal et un lavage. Une résolution positive a été obtenue dans les deux cas.Message clinique clé:Le lavage de l'abdomen de chevaux atteints de péritonite peut être réalisé sous sédation debout, en utilisant une technique laparoscopique. Dans des cas bien choisis, cela permet une visualisation adéquate de l'abdomen dorsal et un lavage abdominal efficace.(Traduit par Dr Serge Messier).

Sabulous cystitis in the horse: 13 cases (2013-2020).

The objective of this study was to describe the clinical findings, medical management, and outcomes of horses with sabulous cystitis, and to describe a high flow bladder lavage procedure in horses that are standing or under general anesthesia. The medical records of 13 horses diagnosed with sabulous cystitis via cystoscopy between 2013 and 2020 were reviewed. Geldings (92%) and Warmbloods (46%) were overrepresented. The most common presenting complaint was urinary incontinence (69%). Complete blood cell count, serum biochemistry profile and urine cytology results were non-specific. Six (46%) horses had various degrees of erosion, ulceration, and hemorrhage of the bladder mucosa. All horses were treated with bladder lavage either with standing sedation (n = 12) or general anesthesia (n = 2), as well as antimicrobials (54%), anti-inflammatory drugs (62%), bethanechol (15%), and phenazopyridine (15%). Most horses (85%) were discharged from the hospital, but only a small percentage (23%) was reported as having no urinary abnormalities on follow-up communication. Key clinical message: Copious bladder lavage with a high flow rate system could mitigate the acute clinical signs and improve the quality of life of horses with sabulous cystitis, but the prognosis for return to previous level of athletic performance and long-term survival is guarded.

Cystite sableuse chez le cheval: 13 cas (2013­2020). L'objectif de cette étude était de décrire les résultats cliniques, la prise en charge médicale et les résultats des chevaux atteints de cystite sableuse, et de décrire une procédure de lavage de la vessie à haut débit chez les chevaux debout ou sous anesthésie générale. Les dossiers médicaux de 13 chevaux diagnostiqués avec une cystite sableuse par cystoscopie entre 2013 et 2020 ont été revus. Les hongres (92 %) et les Warmbloods (46 %) étaient surreprésentés. La plainte la plus fréquente était l'incontinence urinaire (69 %). Un hémogramme complet, le profil biochimique sérique et les résultats de cytologie urinaire n'étaient pas spécifiques. Six chevaux (46 %) présentaient divers degrés d'érosion, d'ulcération et d'hémorragie de la muqueuse de la vessie. Tous les chevaux ont été traités par lavage de la vessie soit avec sédation debout (n = 12) ou anesthésie générale (n = 2), ainsi que des antimicrobiens (54 %), des anti-inflammatoires (62 %), du béthanéchol (15 %) et de la phénazopyridine (15 %). La plupart des chevaux (85 %) sont sortis de l'hôpital, mais seul un petit pourcentage (23 %) a été signalé comme n'ayant aucune anomalie urinaire lors de la communication de suivi.Message clinique clé:Un lavage vésical abondant avec un système à débit élevé pourrait atténuer les signes cliniques aigus et améliorer la qualité de vie des chevaux atteints de cystite sableuse, mais le pronostic du retour au niveau antérieur de performance athlétique et de survie à long terme est réservé.(Traduit par Dr Serge Messier).

Survey of the equine broodmare industry, abortion, and equine herpesvirus-1 vaccination in Ontario.

A survey of Ontario horse breeders was conducted in 2016 and retrospectively asked farm-level management questions regarding herd sizes, vaccination, respiratory disease, and abortion over the years 2014 to 2015. A total of 88 farm owners completed the survey, reporting 857 broodmares. Using logistic regression modelling, management influences on vaccine use, and the reporting of respiratory disease or abortion was investigated. Having veterinary records and the reasons for breeding were significantly associated with the odds of an abortion even after controlling for broodmare herd size. The odds of having respiratory illness on the farm were significantly greater if the farm was the primary source of income even after controlling for farm size. Respondents with primary breeding operations were more likely to utilize vaccines against equine herpesvirus 1 (EHV-1), independent of herd size. Veterinarians were more involved with abortions than with respiratory disease, leaving a significant gap in the opportunities for client education.

Enquête sur l'industrie poulinière, l'avortement et l'utilisation du vaccin contre l'herpèsvirus équin-1 en Ontario. Une enquête auprès des éleveurs de chevaux de l'Ontario a été menée en 2016 et a posé des questions de gestion de l'écurie concernant la taille des troupeaux, la vaccination, les maladies respiratoires et l'avortement, rétrospectivement pour les années 2014 et 2015. Au total, 88 propriétaires d'écuries ont répondu à l'enquête avec 857 juments poulinières. Utilisant des modèles de régression logistique, l'influence du style gestionnaire sur l'utilisation des vaccins et la déclaration des maladies respiratoires ou de l'avortement a été étudiée. La probabilité d'avoir un avortement était significativement associée avec l'utilisation des dossiers vétérinaires et la raison de l'élevage. Les probabilités de souffrir de maladies respiratoires au niveau de la ferme étaient significativement plus élevées si l'écurie était la principale source de revenu. Les répondants ayant des établissements principalement d'élevage étaient plus susceptibles d'utiliser des vaccins contre HVE-1. Les vétérinaires étaient plus impliqués lors de cas d'avortements que lors de maladies respiratoires, ratant une belle opportunité pour l'éducation des clients.(Traduit par les auteurs).

Potomac horse fever in Ontario: Clinical, geographic, and diagnostic aspects.

Clinical findings, geographic locations, laboratory diagnoses, and culture isolation of Neorickettsia spp. in Potomac horse fever (PHF) cases diagnosed in Ontario between 2015 and 2019 are described. Forty-six confirmed PHF cases occurred from late June to early September. Of 41 horses admitted to the Ontario Veterinary College, 28 (68%) survived and 13 (32%) were euthanized due to poor prognosis or financial constraints. Most cases were in southern Ontario along the Canada-USA border. Blood and fecal samples from 43 suspect PHF cases were submitted to 2 laboratories for polymerase chain reaction (PCR) testing for Neorickettsia risticii. Agreement between both laboratories for detection of N. risticii DNA was excellent for feces [κ = 0.932, 95% confidence interval (CI): 0.80 to 1], and fair for blood samples (κ = 0.494, 95% CI: 0.13 to 0.85). Neorickettia spp. were isolated from 16 of 41 (39%) blood samples. DNA analysis confirmed 14 isolates were N. risticii and 2 were N. findlayensis, a novel species of Neorickettsia recently demonstrated to cause PHF.

La fièvre équine du Potomac en Ontario : aspects cliniques, géographiques et diagnostiques. Les résultats cliniques, emplacements géographiques, diagnostics de laboratoire et isolement par culture de Neorickettsia spp. dans les cas de fièvre équine du Potomac (PHF) diagnostiqués en Ontario entre 2015 et 2019 sont décrits. Quarante-six cas confirmés de PHF sont survenus de la fin juin au début septembre. Sur 41 chevaux admis au Ontario Veterinary College, 28 (68%) ont survécu et 13 (32%) ont été euthanasiés en raison d'un mauvais pronostic ou de contraintes financières. La plupart des cas se trouvaient dans le sud de l'Ontario, le long de la frontière canado-américaine. Des échantillons de sang et de matières fécales provenant de 43 cas suspects de PHF ont été soumis à deux laboratoires pour des tests de réaction d'amplification en chaîne par la polymérase (PCR) pour Neorickettsia risticii. La concordance entre les deux laboratoires pour la détection de l'ADN de N. risticii était excellente pour les selles [κ = 0,932, intervalle de confiance (IC) à 95% : 0,80 à 1] et passable pour les échantillons sanguins (κ = 0,494, IC à 95% : 0,13 à 0,85). Neorickettia spp. ont été isolés à partir de 16 des 41 échantillons de sang (39%). L'analyse de l'ADN a confirmé que 14 isolats étaient N. risticii et deux étaient N. findlayensis, une nouvelle espèce de Neorickettsia récemment démontrée comme causant le PHF.(Traduit par Dr Serge Messier).

Valvular endocarditis in the horse: 20 cases (1993-2020).

Medical records of 20 horses with a confirmed diagnosis of valvular endocarditis at the Ontario Veterinary College between January 1, 1993 and February 3, 2020 were reviewed. The diagnosis was based on physical examination findings, complete blood (cell) count (CBC), serum biochemistry, echocardiography, blood culture, and post-mortem findings. Common presenting signs included tachycardia, pyrexia, weight loss, lameness/joint distension, and a heart murmur. Clinicopathological findings included leukocytosis, anemia, hypoalbuminemia, hyperglobulinemia, and elevated inflammatory markers. Culture from 5 horses yielded Actinobacillus equuli in 2 cases and Actinobacillus suis in 1 case. Of the 20 horses included in this study, 17 were euthanized and 3 were treated. Only 1 case had follow-up more than 1 year after discharge.

Endocardite valvulaire chez le cheval : 20 cas (1993­2020). Les dossiers médicaux de 20 chevaux avec un diagnostic confirmé d'endocardite valvulaire au Ontario Veterinary College entre le 1er janvier 1993 et le 3 février 2020 furent revus. Le diagnostic était basé sur les trouvailles de l'examen physique, un comptage sanguin complet (CBC), une biochimie sérique, une échocardiographie, une hémoculture et les trouvailles post-mortem. Les signes fréquents de présentation incluaient tachycardie, pyrexie, perte de poids, boiterie/enflure articulaire et murmure cardiaque. Les trouvailles clinico-pathologiques incluaient leucocytose, anémie, hypoalbuminémie, hyperglobulinémie et augmentation des marqueurs inflammatoires. La culture provenant de cinq chevaux permis d'isoler Actinobacillus equuli dans deux cas et Actinobacillus suis d'un cas. Parmi les 20 chevaux inclus dans cette étude, 17 furent euthanasiés et trois furent traités. Seulement un cas avait un suivi de plus d'un an après le congé.(Traduit par Dr Serge Messier).

Multiple imaging modalities for the diagnosis of tracheal collapse in a calf: A case report.

A 4-month-old Holstein Friesian calf was presented to the Ontario Veterinary College with progressive respiratory distress. The calf was diagnosed with tracheal collapse following perinatal rib fractures. Tracheal collapse has been infrequently reported in calves and is a possible sequela after delivery by forced extraction. Clinical signs can appear from days to months after birth, making the connection between clinical signs and dystocia more challenging. Multiple imaging modalities were used to diagnose and determine the severity of the tracheal collapse, and to establish the most likely cause and prognosis.

Modalités multiples d'imagerie pour le diagnostic de collapse trachéal chez un veau : rapport de cas. Un veau de race Holstein Friesian âgé de 4 mois fut présenté au Ontario Veterinary College pour détresse respiratoire progressive. Un diagnostic de collapse trachéal à la suite de fractures de côtes périnatales fut posé. Le collapse de la trachée n'a été rapporté que très peu fréquemment chez les veaux et serait une séquelle possible d'une mise-bas par extraction forcée. Les signes cliniques peuvent apparaitre des jours jusqu'à des mois après la naissance, rendant l'association entre les signes cliniques et la dystocie encore plus difficile. Des modalités multiples d'imagerie furent utilisées pour diagnostiquer et déterminer la sévérité du collapse trachéal, et afin d'établir la cause la plus probable et le pronostic.(Traduit par Dr Serge Messier).

Plasma transfusions in horses with typhlocolitis/colitis.

The outcome of treatment of horses with plasma for typhlocolitis/colitis at the Ontario Veterinary College-Health Sciences Centre was evaluated. Horses with typhlocolitis/colitis that received a plasma transfusion had higher odds of dying than did non-transfused horses. The clinical usefulness of transfusing plasma to hospitalized hypoproteinemic horses is questioned.

Transfusions de plasma chez les chevaux atteints de typhlocolite/colite. Les résultats du traitement des chevaux à l'aide de plasma pour la typhlocolite/colite au Health Sciences Centre de l'Ontario Veterinary College ont été évalués. Les chevaux atteints de typhlocolite/colite qui avaient reçu une transfusion de plasma présentaient une probabilité accrue de décès par rapport aux chevaux qui n'avaient pas reçu une transfusion. L'utilité clinique de la transfusion de plasma aux chevaux hypoprotéinémiques hospitalisés est remise en question.(Traduit par Isabelle Vallières).

Acute Leukemia in Horses.

Leukemia is broadly divided into acute and chronic lymphocytic and myeloid types based on the proportion of blasts, morphology of cells, and expression of specific antigens on neoplastic cells. Classifying leukemia in horses can be challenging if blasts predominate and since few antibodies to identify cell types are available. The objective of this study was to describe in detail the clinical and pathologic features of acute leukemia in horses. Twelve horses ranging from 0.2 to 25.9 years of age were diagnosed with acute leukemia. Six cases were classified as acute lymphocytic leukemia (ALL) based on predominance of blasts, lack of granulocytic or monocytic differentiation, and detection of CD3, CD20, and/or CD79a antigens by immunohistochemistry. Six other cases were classified as acute myeloid leukemia (AML) with myelomonocytic ( n = 4), basophilic ( n = 1), and eosinophilic ( n = 1) differentiation based on > 20% bone marrow blasts and partial leukocytic differentiation. Reactivity with antibodies to Iba-1/AIF-1, CD172a, and CD163 was determined for all cases of AML. Eleven horses had thrombocytopenia, 10 had neutropenia, 8 had anemia, all had blasts on blood films, and none had leukocytosis. Ten horses had increased serum acute phase proteins. Bone marrow cellularity ranged from 30% to 100%, and the proportion of blasts ranged from 80% to 100% and 30% to 60% in ALL and AML, respectively. Horses were severely ill at diagnosis and euthanized within days or weeks. Unique features of acute leukemia in horses compared to other species were variable lymphocyte antigen expression (ALL) and frequent inflammation (ALL and AML).

Equine duodenitis-proximal jejunitis: A review.

Duodenitis-proximal jejunitis (DPJ) is an inflammatory process of the proximal part of the small intestine and occurs sporadically in horses. It is clinically characterized by an acute onset of ileus and nasogastric reflux leading to systemic signs of toxemia. This review discusses the definition of the disease, potential etiologic agents, clinical findings, epidemiological features, histopathologic and clinico-pathological findings, and medical management of this condition. Salmonella spp., mycotoxins, Clostridium perfringens, and Clostridium difficile have all been associated with the disease but there is limited supporting evidence for any agent other than C. difficile. Particular attention, however, was given to etiological investigations and the data available to support the proposed etiological agents. The potential role of C. difficile as the etiological agent of DPJ, possible pathogenesis, and recent efforts to support this hypothesis are highlighted, but it is recognized that there could be more than one agent that causes the disease.

L'entérite proximale chez le cheval: revision. L'entérite proximale est un processus inflammatoire de la portion proximale du petit intestin qui se présente sporadiquement chez le cheval. Cliniquement, elle est caractérisée par un début soudain d'iléus et de reflux nasogastrique menant à des signes systémiques d'endotoxémie. Cet article discute de la définition de la maladie, des agents étiologiques potentiels, des signes cliniques, des caractéristiques épidémiologiques, des trouvailles histopathologique et clinique et du traitement médical de cette condition. Salmonella spp., les mycotoxines, Clostridium perfringens et Clostridium difficile ont tous été associés avec la maladie, mais les preuves sont limitées pour tout autre agent que C. difficile. Une attention particulière a été mise sur l'étude étiologique et sur les données disponibles pour supporter les agents étiologiques proposés. Le rôle potentiel de C. difficile comme étant l'agent étiologique de l'entérite proximale, la possible pathogénèse et les efforts récents pour supporter cette hypothèse sont soulignés, mais il est reconnu qu'il pourrait y avoir plus d'un agent causatif de la maladie.(Traduit par Dr Marie-Soleil Dubois).

Techniques and Accuracy of Abdominal Ultrasound in Gastrointestinal Diseases of Horses and Foals.

Diagnostic ultrasonography has been used as a test to determine the presence or absence of gastrointestinal disease in horses and foals. General techniques and anatomic landmarks are reviewed. Many clinical reports that have included diagnostic ultrasound as part of their diagnostic process and accuracy studies are necessary to determine the usefulness of diagnostic ultrasound in clinical practice.

Association of unmeasured strong ions with outcome of hospitalized beef and dairy diarrheic calves.

Increased systemic concentrations of L-lactate and unmeasured strong ions (USI) are associated with an increased risk of mortality in human neonates and adults suffering from various diseases. This exploratory study aimed to investigate if values of certain acid-base parameters, especially L-lactate and USI, on admission to hospital are associated with mortality in diarrheic calves. Fifty-five calves < 28 days old admitted to 2 teaching hospitals for diagnosis and treatment of diarrhea were included. Admission demographic, physical examination, blood gas and biochemistry analysis, and outcome data were recorded. Admission acid-base values associated with outcome were assessed using multivariable regression modeling. Calves with elevated plasma L-lactate (OR: 1.30, 95% CI: 1.08 to 1.55; P = 0.005) and USI (OR: 1.40, 95% CI: 1.12 to 1.74; P = 0.003) at admission were more likely to die or to be euthanized. This study revealed that elevated concentrations of L-lactate and USI at admission were positively associated with mortality.

Association des ions forts non mesurés avec les résultats des veaux de boucherie et laitiers diarrhéiques hospitalisés. Des concentrations systémiques accrues de L-lactate et des ions forts non mesurés (IFN) sont associées à un risque accru de mortalité chez les nouveau-nés humains et les adultes souffrant de diverses affections. Cette étude exploratoire visait à vérifier si les valeurs de certains paramètres acides, particulièrement L-lactate et IFN, à l'admission à l'hôpital sont associées à la mortalité chez les veaux diarrhéiques. Cinquante-cinq veaux âgés de < 28 jours admis à deux hôpitaux d'enseignement pour le diagnostic et le traitement ont été inclus. Les données démographiques, l'examen physique, les valeurs des gaz sanguins et de l'analyse biochimique du sang ainsi que l'issu des animaux ont été consignés. Les valeurs de l'équilibre acide-base à l'admission associées à l'issu des animaux ont été évaluées en utilisant une modélisation de régression multi-variable. Il était plus probable que les veaux avec du L-lactate plasmatique élevé (RC : 1,30, IC 95 %, 1,08 à 1,55; P = 0,005) et IFN (RC : 1,40, IC de 95 %, 1,12 à 1,74; P = 0,003), à l'admission meurent ou soient euthanasiés. Cette étude a révélé que des concentrations élevées de L-lactate et d'IFN à l'admission étaient positivement associées à la mortalité.(Traduit par Isabelle Vallières).

An Ecotype of Neorickettsia risticii Causing Potomac Horse Fever in Canada.

UNLABELLED: Neorickettsia (formerly Ehrlichia) risticii is an obligatory intracellular bacterium of digenetic trematodes. When a horse accidentally ingests aquatic insects containing encysted trematodes infected with N. risticii, the bacterium is transmitted from trematodes to horse cells and causes an acute and often fatal disease called Potomac horse fever (PHF). Since the discovery of N. risticii in the United States in 1984, using immunofluorescence and PCR assays, PHF has been increasingly recognized throughout North America and South America. However, so far, there exist only a few stable N. risticii culture isolates, all of which are from horses within the United States, and the strain diversity and environmental spreading and distribution of pathogenic N. risticii strains remain poorly understood. This paper reports the isolation of N. risticii from the blood of a horse with acute PHF in Ontario, Canada. Intracellular N. risticii colonies were detected in P388D1 cells after 47 days of culturing and 8 days after the addition of rapamycin. Molecular phylogenetic analysis based on amino acid sequences of major surface proteins P51 and Ssa1 showed that this isolate is distinct from any previously sequenced strains but closely related to midwestern U.S. strains. This is the first Canadian strain cultured, and a new method was developed to reactivate dormant N. risticii to improve culture isolation. IMPORTANCE: Neorickettsia risticii is an environmental bacterium that lives inside flukes that are parasitic to aquatic snails, insects, and bats. When a horse accidentally ingests insects harboring flukes infected with N. risticii, the bacterium is transmitted to the horse and causes an acute and often fatal disease called Potomac horse fever. Although the disease has been increasingly recognized throughout North and South America, N. risticii has not been cultured outside the United States. This paper reports the first Canadian strain cultured and a new method to effectively culture isolate N. risticii from the horse blood sample. Molecular analysis showed that the genotype of this Canadian strain is distinct from previously sequenced strains but closely related to midwestern U.S. strains. Culture isolation of N. risticii strains would confirm the geographic presence of pathogenic N. risticii, help elucidate N. risticii strain diversity and environmental spreading and distribution, and improve diagnosis and development of vaccines for this dreadful disease.

Acute myeloid leukemia with basophilic differentiation in a 3-year-old Standardbred gelding.

A 3-year-old Standardbred gelding with a history of pyrexia, persistent hemorrhage from the oral cavity, and a large, soft swelling at the junction of the caudal aspect of the mandibular rami and proximal neck was evaluated. The horse had neutropenia and anemia, with atypical granulated cells in a blood smear. Additional tests confirmed acute myeloid leukemia with basophilic differentiation, which has been reported in humans, cats, dogs, and cattle but not horses.

Leucémie myéloïde aiguë avec différenciation basophile chez un hongre Standardbred âgé de 3 ans. Nous avons évalué un hongre Standardbred âgé de 3 ans avec une anamnèse de pyrexie, d'hémorragie persistante de la cavité orale et d'une grosse enflure molle à la jonction de l'aspect caudal des rameaux mandibulaires et du cou proximal. Le cheval souffrait de neutropénie et d'anémie avec des cellules granulées au frottis sanguin. Des tests additionnels ont confirmé une leucémie myéloïde avec différenciation basophile, qui avait déjà été signalée chez les humains, les chats, les chiens et le bétail, mais pas chez les chevaux.(Traduit par Isabelle Vallières).