Environmental risk factors for UV-induced cutaneous neoplasia in horses: A GIS approach.

Objective: Ultraviolet light (UV) is a risk factor for the development of cutaneous neoplasia in many mammalian species. This study evaluated UV exposure as a risk factor of concern for the development of cutaneous neoplasia in equine species due to the significant UV exposure that may accrue over their lifetimes. Animals and samples: Neoplastic biopsy specimens from 3272 horses that were submitted over a 10-year period to the Colorado State University Diagnostic Medicine Center and to the University of Saskatchewan Western College of Veterinary Medicine and Prairie Diagnostic Services were evaluated. Procedure: This retrospective study assessed the spatial relationships between altitude, latitude, longitude, and UV maximum value and the probability of UV-induced cutaneous neoplasia. Results: Cases from areas at high altitude proved to have a higher prevalence of UV-induced cutaneous neoplasia than those from areas at lower elevations. A multivariable regression analysis demonstrated that altitude was the only factor significantly and positively associated with the diagnosis of UV-induced neoplasia. Conclusion and clinical relevance: Evidence of cutaneous neoplasia in horses and environmental factors that influence the degree of UV exposure in a geographic location may aid in diagnosis and suggest preventive measures from UV overexposure.

Facteurs de risque environnementaux des néoplasies cutanées induites par les UV chez le cheval : une approche SIG. Objectif: La lumière ultraviolette (UV) est un facteur de risque pour le développement de néoplasies cutanées chez de nombreuses espèces de mammifères. Cette étude a évalué l'exposition aux UV en tant que facteur de risque préoccupant pour le développement de néoplasies cutanées chez les équidés en raison de l'exposition importante aux UV qui peut s'accumuler au cours de leur vie. Animaux et échantillons: Des échantillons de biopsie néoplasique de 3272 chevaux qui ont été soumis sur une période de 10 ans au Colorado State University Diagnostic Medicine Center et au University of Saskatchewan Western College of Veterinary Medicine and Prairie Diagnostic Services ont été évalués. Procédure: Cette étude rétrospective a évalué les relations spatiales entre l'altitude, la latitude, la longitude et la valeur maximale des UV et la probabilité de néoplasie cutanée induite par les UV. Résultats: Les cas des régions de haute altitude se sont avérés avoir une prévalence plus élevée de néoplasie cutanée induite par les UV que ceux des régions de basse altitude. Une analyse de régression multivariée a démontré que l'altitude était le seul facteur significativement et positivement associé au diagnostic de néoplasie induite par les UV. Conclusion et pertinence clinique: Les preuves de néoplasie cutanée chez les chevaux et les facteurs environnementaux qui influencent le degré d'exposition aux UV dans un lieu géographique peuvent aider au diagnostic et suggérer des mesures préventives contre la surexposition aux UV.(Traduit par Dr Serge Messier).

A retrospective study of equine perinatal loss in Canada (2007 to 2020).

Objective: This study aims to identify the most common causes of equine perinatal loss up to 7 d of age in Canada. Animal: Equine. Procedure: Necropsy reports from 360 equine perinatal loss cases were acquired from provincial veterinary diagnostic labs across Canada. Each case was classified into a basic cause (noninfectious, infectious, or unidentified) of perinatal loss, then further classified into primary and secondary categories for analysis. Results: Of the basic causes of perinatal loss, noninfectious causes were the most common. Bacterial causes, such as septicemia, were the most common primary diagnosis overall. Actinobacillus was the most commonly identified bacterial species. Conclusion: This study showed similar results to those of studies conducted in other countries, including having similar etiologic agents identified. The high prevalence of thyroid hyperplasia identified in this study is notable and was not reported in other, similar retrospective studies, despite being reported in locations other than Canada. Clinical relevance: Perinatal loss can have important economic consequences for horse breeders; thus, identification of the most common causes is of interest to both veterinarians and breeders.

Étude rétrospective des décès périnataux équins au Canada (2007 à 2020). Objectif: Cette étude vise à identifier les causes les plus courantes de décès périnatal équin jusqu'à l'âge de 7 jours au Canada. Animal: Cheval. Procédure: Les rapports d'autopsie de 360 cas de décès périnatal équin ont été acquis auprès de laboratoires provinciaux de diagnostic vétérinaire à travers le Canada. Chaque cas a été classé selon une cause fondamentale (non infectieuse, infectieuse ou non identifiée) de décès périnatal, puis classé en catégories primaires et secondaires pour analyse. Résultats: Parmi les causes fondamentales de décès périnatal, les causes non infectieuses étaient les plus fréquentes. Les causes bactériennes, telles que la septicémie, étaient le diagnostic principal le plus courant dans l'ensemble. Actinobacillus était le genre bactérien le plus fréquemment identifié. Conclusion: Cette étude a montré des résultats similaires à ceux d'études menées dans d'autres pays, y compris l'identification d'agents étiologiques similaires. La forte prévalence de l'hyperplasie thyroïdienne identifiée dans cette étude est remarquable et n'a pas été signalée dans d'autres études rétrospectives similaires, bien qu'elle ait été signalée dans des endroits autres que le Canada. Pertinence clinique: Le décès périnatal peut entraîner des conséquences économiques importantes pour les éleveurs de chevaux; ainsi, l'identification des causes les plus courantes intéresse à la fois les vétérinaires et les éleveurs.(Traduit par Dr Serge Messier).

A 13-year retrospective study of equine abortions in Canada.

Objective: The purpose of this study was to identify the most common causes of equine abortion in Canada, and to compare findings to similar reports from other countries. Animal: Equine. Procedure: Necropsy reports from 901 equine abortion cases were acquired from provincial veterinary diagnostic laboratories across Canada. The final diagnosis was classified into basic abortion causes (infectious, non-infectious, unknown) and into primary and secondary categories for analysis. Results: Non-infectious causes of abortion were the most frequently identified in Canada, with fetoplacental causes, including umbilical cord torsion or placental insufficiency, being the most common primary diagnosis category. Streptococcus and Escherichia were the bacterial species most often identified as causing infectious abortions, whereas equine herpesvirus-1 was implicated in all viral abortions identified. Conclusion: The high rate of non-infectious causes of abortion was similar to previous studies conducted in the United Kingdom. This finding was somewhat dissimilar to the USA, which had higher rates of infectious abortions, despite Canada's geographic proximity to the USA. The reason for variations among countries in equine abortion causes is unknown. Clinical relevance: The large number of fetoplacental-related abortions identified in this study emphasized the need for submission of both the fetus and placenta, if possible, to increase the probability of a diagnosis. In addition, the high rate of unidentified diagnoses suggests a need for further study into both non-infectious and infectious causes of equine abortion, including potential development of new diagnostic tests or markers.

Objectif: Le but de cette étude était d'identifier les causes les plus courantes d'avortement chez les équidés au Canada et de comparer les résultats à des rapports similaires provenant d'autres pays. Animal: Chevaux. Procédure: Les rapports de nécropsie de 901 cas d'avortements équins ont été obtenus auprès de laboratoires provinciaux de diagnostic vétérinaire à travers le Canada. Le diagnostic final a été classé en causes d'avortement de base (infectieuses, non infectieuses, inconnues) et en catégories primaires et secondaires pour analyse. Résultats: Les causes non-infectieuses d'avortement étaient les plus fréquemment identifiées au Canada, les causes foetoplacentaires, y compris la torsion du cordon ombilical ou l'insuffisance placentaire, étant la catégorie de diagnostic principal la plus courante. Les espèces bactériennes des genres Streptococcus et Escherichia étaient les plus souvent identifiées comme étant à l'origine d'avortements infectieux, alors que l'herpèsvirus équin-1 était impliqué dans tous les avortements viraux identifiés. Conclusion: Le taux élevé de causes non-infectieuses d'avortement était similaire aux études précédentes menées au Royaume-Uni. Cette observation était quelque peu différente de celles des États-Unis, qui avaient des taux plus élevés d'avortements infectieux, malgré la proximité géographique du Canada avec les États-Unis. La raison des variations entre les pays dans les causes d'avortement équin est inconnue. Pertinence clinique: Le grand nombre d'avortements liés aux causes foetoplacentaires identifiés dans cette étude a souligné la nécessité de soumettre à la fois le foetus et le placenta, si possible, pour augmenter la probabilité d'un diagnostic. En outre, le taux élevé de diagnostics non identifiés suggère la nécessité d'une étude plus approfondie des causes non-infectieuses et infectieuses de l'avortement équin, y compris le développement potentiel de nouveaux tests de diagnostic ou marqueurs.(Traduit par Dr Serge Messier).

Bilateral second pharyngeal cleft cysts in 2 calves on the same farm.

Pharyngeal cleft cysts (also called branchial cleft cysts) are rare congenital defects of the pharynx region that appear as soft, fluctuant cystic structures on the ventral neck. These cysts are formed by anomalous regression of the pharyngeal clefts during embryonic development and are lined by pseudostratified columnar to squamous, partially ciliated epithelium on histopathology. Development of these cysts is sporadic, with no currently identified risk factors in veterinary species. The cysts are typically unilateral, and primarily diagnosed in mature animals of various species. The objective of this article is to report 2 cases of bilateral second pharyngeal cleft cysts in 2 calves with no shared pedigree, located on the same farm. To the authors' knowledge, this is the first report of geographically linked second pharyngeal cleft cysts in veterinary species, and the first cases of bilateral cysts in cattle. Key clinical message: Pharyngeal cleft cysts are an important differential for soft, fluctuant, and cystic structures on the ventral neck of all species. These cases are typically unilateral, diagnosed in mature animals and are sporadic with no currently identified risk factors in veterinary species.

Kystes bilatéraux de la deuxième fente pharyngée chez deux veaux d'un même élevage. Les kystes de la fente pharyngée (également appelés kystes de la fente branchiale) sont des anomalies congénitales rares de la région du pharynx qui apparaissent sous la forme de structures kystiques molles et fluctuantes sur le cou ventral. Ces kystes sont formés par une régression anormale des fentes pharyngées au cours du développement embryonnaire et sont bordés par un épithélium cylindrique pseudostratifié à squameux, partiellement cilié en histopathologie. Le développement de ces kystes est sporadique et aucun facteur de risque n'est actuellement identifié chez les espèces animales. Les kystes sont généralement unilatéraux et principalement diagnostiqués chez des animaux matures de diverses espèces. L'objectif de cet article est de rapporter deux cas de kystes bilatéraux de la deuxième fente pharyngée chez deux veaux sans pedigree partagé, localisés sur la même ferme. À la connaissance des auteurs, il s'agit du premier rapport de kystes de la deuxième fente pharyngée liés géographiquement chez les espèces vétérinaires, et des premiers cas de kystes bilatéraux chez les bovins.Message clinique clé :Les kystes de la fente pharyngée sont un différentiel important pour les structures molles, fluctuantes et kystiques sur le cou ventral de toutes les espèces. Ces cas sont généralement unilatéraux, diagnostiqués chez des animaux matures et sporadiques sans facteurs de risque actuellement identifiés chez les espèces vétérinaires.(Traduit par Dr Serge Messier).

Prevalence of Equus caballus Papillomavirus Type-2 Infection and Seropositivity in Asymptomatic Western Canadian Horses.

Equus caballus papillomavirus type 2 (EcPV-2) has been recognized as a potential cause of a subset of genital squamous cell carcinomas (SCCs) in horses. In the current study, we measured EcPV-2 seropositivity in 50 healthy horses from Western Canada, and these were compared to a herd of horses with known EcPV-2 exposure. Second, the presence of EcPV-2 DNA was measured using EcPV-2-specific PCR (polymerase chain reaction), performed on a variety of tissues collected at necropsy from 70 horses that lacked any history, gross, or histologic evidence of neoplasia or papillomavirus-associated disease. EcPV-2-specific RNA in situ hybridization (R-ISH) was performed on PCR-positive samples to identify the specific tissues infected. The prevalence of asymptomatic infection with EcPV-2 in Western Canadian horses was 20/70 (29%). Exposure to EcPV-2 as measured by seropositivity was 18/50 (36%). EcPV-2 positivity by anatomic location, as measured by R-ISH, was as follows: penis 10/29 (35%), vulva 5/34 (15%), eyelid 8/68 (12%), oral mucosa 7/65 (11%), skin from muzzle 7/68 (10%), and retropharyngeal lymph node 2/64 (3%). The youngest horses with EcPV-2 infection, based on PCR, were fetuses, suggesting for the first time that vertical transmission of EcPV-2 occurs in horses. The current study observed an increased prevalence of EcPV-2 as compared to previous studies. We suggest that this difference is due to our use of biopsies in place of superficial swabs. We propose that EcPV-2 infection in asymptomatic horses is more common than previously reported and that the virus' role in equine genital SCCs may be more complex than originally thought.

Prevalence and Prognostic Impact of Equus caballus Papillomavirus Type 2 Infection in Equine Squamous Cell Carcinomas in Western Canadian Horses.

Equus caballus papillomavirus type-2 (EcPV-2) has been proposed as a causal factor in equine genital squamous cell carcinoma (SCC). This study had 2 objectives: first, calculate the frequency of papillomavirus (PV) and EcPV-2 infection in papillomas, carcinomas in situ (CIS), and SCCs in Western Canadian horses; and second, determine if EcPV-2 status of equine SCCs is associated with overall survival (OS). EcPV-2 status of 115 archived tissue samples, spanning 6 years, was determined using broad spectrum (MY09/11) and EcPV-2-specific polymerase chain reaction (PCR) assays, EcPV-2-E6/E7 chromogenic RNA in situ hybridization (R-ISH), and amplicon sequencing. A retrospective survey gathered data on history, outcome, breeding, treatment, and rationales of referring veterinarians when managing PV-associated diseases. Histologic grade and completeness of surgical margins of SCCs were also considered. EcPV-2 DNA was identified in 10/58 (17%) SCC, 8/27 (30%) papillomas, 0/5 CIS, and 0/11 lesions identified as "other." Overall, 18/101 (18%) of these lesions were positive for EcPV-2. EcPV-2 was identified in 10/35 (29%) SCCs arising from genital tissues but in 0/22 SCCs from other locations. There was no association between breeding history and EcPV-2 status of genital SCCs. EcPV-2 status of genital SCCs was not associated with OS (P = .76). The strongest negative predictors of OS were a lack of treatment (P < .01) and recurrence post-treatment (P < .01). Weaker predictors of OS included older age at time of diagnosis (P = .02). Completeness of margins at surgical excision, concurrent disease, treatment type, anatomic location of the SCC (anogenital vs other), and histologic grade of the SCC did not influence OS (P > .1).

Mouse model to study pulmonary intravascular macrophage recruitment and lung inflammation in acute necrotizing pancreatitis.

Patients suffering from severe acute pancreatitis (AP) can develop acute lung injury (ALI) with poor outcomes and the mechanisms involved remain incompletely understood. Pulmonary intravascular macrophages (PIMs), which are credited as promoters of ALI, are not constitutively present in humans and rodents; however, there is evidence of PIM recruitment in rodents during some pathological conditions, such as hepatic diseases. Therefore, this study assesses PIM recruitment in the lungs of a mouse model of acute necrotizing pancreatitis (ANP) induced with L-arginine monohydrochloride. Mice were euthanized after 24 h, 72 h and 120 h. Control mice received sham injections of saline. Pancreatic histopathological grading and plasma amylase were used to confirm the development of ANP in L-arginine-treated mice. Histopathological grading of lungs from the ANP mice at 72 h showed increased mononuclear phagocytes in alveolar septa, compared to that from the controls. Lungs from the ANP mice also showed increased numbers of CD68-immunopositive alveolar septal macrophages, suggestive of PIM recruitment, compared to those from the controls. Lungs from the ANP mice showed increased expression of IL-6, IL-10, monocyte chemoattractant protein 1 (MCP-1) and von Willebrand factor compared to those from the controls. The recruitment of CD68-positive septal macrophages was not observed in MCP-1 knockout mice with ANP at 72 h when compared to C57BL/6 wild-type mice. Taken together, we developed a mouse model of PIM recruitment dependent on MCP-1 that allows us to explore their roles in ANP-associated ALI.

Fine-needle aspiration in the diagnosis of equine skin disease and the epidemiology of equine skin cytology submissions in a western Canadian diagnostic laboratory.

Fine-needle aspiration (FNA) is commonly used to diagnose skin disease in companion animals, but its use in horses appears to be infrequent. Equine veterinarians in western Canada were surveyed to determine their opinions about FNA and 15 years of diagnostic submissions were used to compare the perceived to actual value of FNA in the diagnosis of skin disease in horses. Practitioners viewed FNA as quick, easy, economical, and minimally invasive. However, most veterinarians rarely chose to use FNA due to a perception that sample quality and diagnostic yield were poor and there was a narrow range of diseases the technique could diagnose. Analysis of the FNA cytology samples from a veterinary diagnostic laboratory showed a wide variety of equine skin disease conditions, but the frequency of non-diagnostic results was significantly higher in equine submissions compared to those from dogs and cats.

Aspiration à l'aiguille pour le diagnostic des maladies de la peau équines et épidémiologie des soumissions cytologiques de la peau équine dans un laboratoire diagnostique de l'Ouest canadien. L'aspiration à l'aiguille est communément utilisée pour diagnostiquer les maladies de la peau chez les animaux de compagnie, mais son utilisation semble peu commune chez les chevaux. On a effectué un sondage auprès des vétérinaires équins de l'Ouest canadien afin de déterminer leurs opinions à propos de l'aspiration à l'aiguille et on a utilisé 15 années de soumissions diagnostiques pour comparer la valeur perçue et réelle de l'aspiration à l'aiguille pour le diagnostic des maladies de la peau chez les chevaux.Les praticiens considèrent l'aspiration par aiguille comme une méthode rapide, facile, économique et minimalement invasive. Cependant, la plupart des vétérinaires choisissent rarement l'aspiration à l'aiguille en raison de la perception que la qualité de l'échantillon et les résultats diagnostiques sont mauvais et que la technique peut diagnostiquer un nombre limité de maladies.L'analyse des échantillons de cytologie de l'aspiration à l'aiguille provenant d'un laboratoire de diagnostic vétérinaire a montré un vaste éventail d'affections de la peau équines, mais la fréquence des résultats non diagnostiques était significativement supérieure dans les soumissions équines comparativement à celles provenant de chiens et chats.(Traduit par Isabelle Vallières).

Anthrax vaccine associated deaths in miniature horses.

During a widespread anthrax outbreak in Canada, miniature horses were vaccinated using a live spore anthrax vaccine. Several of these horses died from an apparent immune-mediated vasculitis temporally associated with this vaccination. During the course of the outbreak, other miniature horses from different regions with a similar vaccination history, clinical signs, and necropsy findings were found.

Vaccin contre l'anthrax associé à la mort de chevaux miniatures. Durant une vaste éclosion d'anthrax au Canada, des chevaux miniatures ont été vaccinés en utilisant un vaccin à base de spores viables d'anthrax. Plusieurs chevaux sont morts d'une vasculite d'origine immunologique associée temporellement avec cette vaccination. Pendant l'éclosion, on a trouvé d'autres chevaux miniatures de régions différentes présentant une anamnèse de vaccination, de signes cliniques et de résultats d'autopsie semblables.(Traduit par Isabelle Vallières).

Skin Diseases in Horses.

Skin disease in horses is a common and potentially challenging clinical problem. Information pertaining to skin disease is lacking in horses when compared with that in other companion animal species. Certainly, both horse-specific and location-specific patterns are present, but these can often be confounded by other factors. There are many possible ways in which to organize skin disease; in this article, they are organized based loosely on their most common clinical feature. Space limits the number of conditions that can be described here, and those chosen were seen relatively frequently in a multiinstitutional study of equine biopsies.

Fascioloides magna infection causing fatal pulmonary hemorrhage in a steer.

A feedlot steer died suddenly without exhibiting signs of clinical illness. Cysts containing Fascioloides magna were found in the liver and lung. Fatal pulmonary hemorrhage was associated with these flukes. Neither death nor clinical pulmonary disease has been previously attributed to infections of adult cattle by F. magna.

Infection àFascioloides magnacausant une hémorragie pulmonaire mortelle chez un bouvillon. Un bouvillon d'un parc d'engraissement meurt soudainement sans manifester de signes d'une maladie clinique. Des kystes contenant Fascioloides magna ont été trouvés dans le foie et les poumons. Une hémorragie pulmonaire mortelle a été associée à ces douves. Ni la mort ni la maladie pulmonaire clinique n'avaient été antérieurement attribuées aux infections des bovins adultes par F. magna.(Traduit par Isabelle Vallières).

SARS-CoV-2 Surveillance of Wild Mice and Rats in North American Cities.

From July 2020 to June 2021, 248 wild house mice (Mus musculus), deer mice (Peromyscus maniculatus), brown rats (Rattus norvegicus), and black rats (Rattus rattus) from Texas and Washington, USA, and British Columbia, Canada, were tested for SARS-CoV-2 exposure and infection. Two brown rats and 11 house mice were positive for neutralizing antibodies using a surrogate virus neutralization test, but negative or indeterminate with the Multiplexed Fluorometric ImmunoAssay COVID-Plex, which targets full-length spike and nuclear proteins. Oro-nasopharyngeal swabs and fecal samples tested negative by RT-qPCR, with an indeterminate fecal sample in one house mouse. Continued surveillance of SARS-CoV-2 in wild rodents is warranted.

Malignant transformation of a putative eyelid papilloma to squamous cell carcinoma in a dog.

A 6-year-old female spayed Chihuahua was presented for the evaluation of generalized pigmented cutaneous masses, one of which was present on the lower right eyelid. The dog was not on immunosuppressive medications and did not have historical or laboratory evidence of underlying endocrine disease, including hypothyroidism and hyperadrenocorticism. Histopathology, immunohistochemistry, and polymerase chain reaction of a cutaneous biopsy from the left antebrachium containing representative lesions confirmed viral papillomatosis. Additionally, histopathology of the antebrachial mass revealed regions of epithelial dysplasia suggestive of possible early transformation to malignancy. Over the course of 5 months, the mass on the right lower eyelid progressed to encompass and efface the majority of the eyelid margin. Additionally, the eyelid tumor had changed from an ovoid, brown pigmented mass to an irregular, flesh-colored mass. At the dog's last recheck examination, a corneal ulcer had developed beneath the irregular dorsal margin of the tumor. Histopathology of the eyelid mass was consistent with squamous cell carcinoma (SCC) and was positive for the presence of papillomavirus using polymerase chain reaction. This report describes the transformation of a putative viral eyelid papilloma into a malignant SCC in an adult dog.

Non-neoplastic lesions of equine skin in the central United States and Canada: a retrospective study.

A retrospective study evaluated the clinical data and histologic features of non-neoplastic dermatologic lesions in skin biopsies from horses, donkeys, and mules submitted over a 10-year period to the Colorado State University Diagnostic Medicine Center and to the University of Saskatchewan Western College of Veterinary Medicine and Prairie Diagnostic Services. A total of 1793 non-neoplastic biopsies were available for analysis. Based on the histologic description and morphologic diagnosis, each submission was classified as inflammatory, or non-neoplastic/non-inflammatory. Results of this study demonstrate that non-neoplastic equine cutaneous biopsies are predominantly inflammatory, but histopathology alone may not be sufficient to definitively identify the underlying etiologies driving inflammatory lesions. Clinical correlation, including breed, age, and distribution of the cutaneous lesion, as well as ancillary tests such as bacterial or fungal culture are required to complete the clinical picture and arrive at the appropriate clinical diagnosis.

Lésions non néoplasiques de la peau équine dans le centre des États-Unis et du Canada : une étude rétrospective. Une étude rétrospective a évalué les données cliniques et les caractéristiques histologiques des lésions dermatologiques non néoplasiques des biopsies cutanées de chevaux, d'ânes et de mules soumises pendant une période de 10 ans au Diagnostic Medicine Center de l'Université de l'État du Colorado, au College of Veterinary Medicine de l'Université de la Saskatchewan et à Prairie Diagnostic Services. Un total de 1793 biopsies non néoplasiques étaient disponibles aux fins d'analyse. En se fondant sur la description histologique et le diagnostic morphologique, chaque soumission a été classée comme inflammatoire ou non néoplasique/non inflammatoire. Les résultats de cette étude démontrent que les biopsies cutanées équines non néoplasiques sont surtout inflammatoires, mais que l'histopathologie seule peut ne pas être suffisante pour identifier définitivement les étiologies sous-jacentes des lésions inflammatoires. La corrélation clinique, incluant la race, l'âge et la distribution de la lésion cutanée ainsi que des tests auxiliaires, comme une culture bactérienne ou fongique, est requise pour achever le portrait clinique et parvenir à un diagnostic clinique approprié.(Traduit par Isabelle Vallières).

Detection of Chlamydia abortus in aborted chorioallantoises of horses from Western Canada.

Chlamydiae are reported to cause abortion in several species, however the association between Chlamydia sp. and equine abortions is poorly understood. A zoonotic transfer event of C. psittaci from aborted equine tissues in Australia has emphasized the need to better understand the prevalence of this pathogen in equine populations. The prevalence of chlamydia in equine abortions in North America has not been investigated thoroughly. We examined 99 formalin-fixed, paraffin-embedded placental samples submitted between 2009 and 2020 from equine abortions in Western Canada using chlamydia-specific 16S rRNA conventional PCR testing; 26 of 99 submissions tested positive for chlamydial DNA. Most of these submissions (n = 17) had no final diagnosis noted on their original pathology reports. DNA sequencing identified 22 of the 26 cases as C. abortus; 21 of the 22 C. abortus-positive samples were positive on chlamydial immunohistochemistry. These findings contrast with studies in Europe that found a low prevalence of chlamydiae using similar methodology. The high prevalence of the potentially zoonotic C. abortus identified in our study suggests that more substantial biosecurity protocols may be warranted for equine foaling, abortion, and stillbirth in Western Canada to prevent zoonotic transfer of the pathogen.

Detection of multiple human enteropathogens in Norway rats (Rattus norvegicus) from an under-resourced neighborhood of Vancouver, British Columbia.

Urban Norway rats (Rattus norvegicus) can carry various human pathogens, and may be involved in pathogen propagation and transmission to humans. From January 31-August 14, 2021, a community outbreak of Shigella flexneri serotype 2a occurred among unhoused or poorly housed people in the Downtown Eastside neighborhood of Vancouver, British Columbia, Canada. The source could not be identified; however, patients reported contact with rats, and previous studies indicated transmission of rat-associated zoonotic pathogens among the unhoused or poorly housed residents of this neighborhood. The study objective was to determine if rats trapped in the outbreak area were carriers of Shigella spp. and other zoonotic enteric pathogens. From March 23-April 9, 2021, 22 rats were lethally trapped within the outbreak area. Colonic content was analyzed using the BioFire FilmArray Gastrointestinal (multiplex PCR) panel for human enteropathogens, which detected: Campylobacter spp. (9/22), Clostridioides difficile (3/22), Yersinia enterocolitica (5/22), Cryptosporidium spp. (8/22), Giardia duodenalis (5/22), Rotavirus A (1/22), enteroaggressive Escherichia coli (2/22), enteropathogenic E. coli (10/22), and Shigella spp. or enteroinvasive E. coli (EIEC) (3/22). An ipaH PCR assay was used for targeted detection of Shigella spp./EIEC, with five rats positive. Two samples contained insertion sites unique to S. flexneri isolated from the human outbreak. This study highlights the potential for rats to carry a broad range of human pathogens, and their possible role in pathogen maintenance and/or transmission.

IIB or not IIB, part 2: assessing inter-rater and intra-rater repeatability of the Kenney-Doig scale in equine endometrial biopsy evaluation.

Inter- and intra-rater variability negatively affects the reliability of various histopathology grading scales used as prognostic aids in human and veterinary medicine. The Kenney-Doig categorization (grading) scale, which is used to associate equine endometrial histologic lesions with prognostic estimation of a broodmare's reproductive potential, has not been evaluated for inter- or intra-rater variability, to our knowledge. To assess whether the Kenney-Doig system produces reliable results among observers, 8 pathologists, all with American College of Veterinary Pathologists certification, were recruited to blindly categorize the same set of 63 digital equine endometrial biopsy slides as well as to re-evaluate anonymously 21 of 63 of these slides at a later time. Cohen kappa values for pairwise comparison of final Kenney-Doig categories were -0.05 to 0.46 (unweighted) and 0.08-0.64 (weighted), with an average Light kappa of 0.19 (unweighted) and 0.36 (weighted) across all 8 pathologists, 0.14 (unweighted) and 0.33 (weighted) for pathologists at different institutions, and 0.22 (unweighted) and 0.46 (weighted) for pathologists at the same institution. Intra-class correlations measuring intra-rater agreement were 0.12-0.77 with an average of 0.55 for all 8 pathologists. We found that only slight-to-moderate inter-rater agreement and poor-to-good intra-rater agreement was produced by 8 pathologists using the Kenney-Doig scale, suggesting that the system is subject to significant observer variability and care should be taken when communicating Kenney-Doig categories to submitting clinicians with emphasis on the quality of endometrial lesions present instead of the category and associated expected foaling rate.

IIB or not IIB, part 1: retrospective evaluation of Kenney-Doig categorization of equine endometrial biopsies at a veterinary diagnostic laboratory and comparison with published reports.

The Kenney-Doig scale is a histopathology categorization (grading) system often used as the standard for assessing endometrial disease and communicating prognostic fertility information for equine breeding prospects. We investigated how Kenney-Doig categories compared within the same institution and across different institutions to determine if observer variability may contribute to category frequencies. We conducted a retrospective analysis of all equine endometrial submission records between 1998 and 2018 at the Western College of Veterinary Medicine (WCVM) and Prairie Diagnostic Services (PDS). Of 726 biopsies, we found the following category distribution: 46 of 726 (6.3%) I, 307 of 726 (42.3%) IIA, 326 of 726 (44.9%) IIB, and 47 of 726 (6.5%) III. We also conducted a review of the literature and included 6 studies reporting Kenney-Doig category distributions. Chi-square analysis showed significant differences between the category distribution found at WCVM and PDS and the category distribution reported in the 6 studies. To account for differences in mare populations, individual category distributions were generated for 5 pathologists at the WCVM and PDS. The Fisher exact test among these 5 Kenney-Doig categories revealed significant differences in category tendencies, suggesting that observer variation affects the use of the scale. Our results suggest that there is a need for prospective inter-rater and intra-rater agreement studies of the repeatability of the Kenney-Doig scale.

Macroscopic, Histologic, and Immunomodulatory Response of Limb Wounds Following Intravenous Allogeneic Cord Blood-Derived Multipotent Mesenchymal Stromal Cell Therapy in Horses.

Limb wounds are common in horses and often develop complications. Intravenous multipotent mesenchymal stromal cell (MSC) therapy is promising but has risks associated with intravenous administration and unknown potential to improve cutaneous wound healing. The objectives were to determine the clinical safety of administering large numbers of allogeneic cord blood-derived MSCs intravenously, and if therapy causes clinically adverse reactions, accelerates wound closure, improves histologic healing, and alters mRNA expression of common wound cytokines. Wounds were created on the metacarpus of 12 horses. Treatment horses were administered 1.51-2.46 × 108 cells suspended in 50% HypoThermosol FRS, and control horses were administered 50% HypoThermosol FRS alone. Epithelialization, contraction, and wound closure rates were determined using planimetric analysis. Wounds were biopsied and evaluated for histologic healing characteristics and cytokine mRNA expression. Days until wound closure was also determined. The results indicate that 3/6 of treatment horses and 1/6 of control horses experienced minor transient reactions. Treatment did not accelerate wound closure or improve histologic healing. Treatment decreased wound size and decreased all measured cytokines except transforming growth factor-ß3. MSC intravenous therapy has the potential to decrease limb wound size; however, further work is needed to understand the clinical relevance of adverse reactions.

Penetrating metallic foreign bodies as a cause of peritonitis in 3 horses.

Three cases of penetrating metallic foreign bodies causing peritonitis in horses are reported. These cases were presented with varying clinical complaints and duration of clinical signs. Entry of foreign bodies into the abdominal cavity through the skin and body wall is reported for the first time.