Equine herpesvirus 1-associated ulcerative dermatitis in a horse.

This case report describes the clinical and histopathological findings of an infection caused by equine herpesvirus-1 (EHV-1) in a horse showing respiratory signs and a papular, crusted and ulcerative dermatitis involving mucosae. This diagnosis was supported by real-time PCR positive for EHV-1 on nasal swabs and tissues.

Cet article décrit les données cliniques et histopathologiques d'une infection due à EHV-1 (equine herpesvirus - 1) chez un cheval présentant des signes respiratoires et une dermatite papuleuse, croûteuse et ulcérative s'étendant aux muqueuses. Le diagnostic a été supporté par une PCR en temps réel positive pour EHV-1 sur tissus et écouvillon nasal. Dieser Fallbericht beschreibt die klinischen und histopathologischen Befunde einer Infektion durch das equine Herpesvirus-1 (EHV-1) bei einem Pferd, welches respiratorische Zeichen zeigte und eine papulöse, krustige und ulzerative Dermatitis, von der auch die Schleimhäute betroffen waren. Die Diagnose wurde durch eine Real-time PCR Untersuchung, die an Tupfern aus der Nase und aus Gewebe positiv auf EHV-1 verlief, unterstützt.

Este informe de caso describe los hallazgos clínicos e histopatológicos de una infección causada por herpesvirus equino tipo-1 (EHV-1) en un caballo que mostraba signos respiratorios y una dermatitis papular, con costras y ulceras afectando las mucosas. Este diagnóstico fue corroborado por una PCR en tiempo real positiva para EHV-1 en hisopos nasales y tejidos.

Este relato de caso descreve os achados clínicos e histopatológicos de uma infecção causada por herpesvírus equino tipo-1 (EHV-1) em um cavalo que apresentou sinais respiratórios e dermatite papular, crostosa e ulcerativa envolvendo mucosas. Este diagnóstico foi confirmado por PCR em tempo real positivo para EHV-1 em swabs nasais e tecidos.

A retrospective study on methicillin-resistant Staphylococcus spp. isolated from horses admitted to a Canadian veterinary teaching hospital between 2008 and 2018.

The goals of this retrospective study were to: determine the frequency of methicillin-resistant Staphylococcus spp. (MRS) isolated from horses admitted to an equine veterinary teaching hospital in Quebec from 2008 to 2018, investigate the patterns of antimicrobial resistance (AMR), and evaluate the distribution of MRS and methicillin-sensitive Staphyloccocus spp. (MSS) by body site. During this period, 311 Staphylococcus spp. were isolated from 273 horses and 127 of these isolates were submitted to antimicrobial susceptibility testing. Of these 127 isolates, 24 (18.9%) were MRS, and among the S. aureus (n = 76), 19 (25%) were MRS. The odds of detecting an MRS increased (25%) each year [95% confidence interval (CI) (1% to 55%), P = 0.039]. The highest frequencies of resistance were to tetracycline and gentamicin. Among the MRS isolates, 12% were susceptible to both tetracycline and gentamicin. The most frequently sampled body sites were "soft-tissues." There was no significant difference (P = 0.93) in the body site distribution of MRS and MSS isolates.

Étude rétrospective sur les Staphylococcus spp. résistants à la méthicilline isolés de chevaux admis à un hôpital d'enseignement vétérinaire au Canada entre 2008 et 2018. Les buts de cette étude rétrospective étaient : déterminer la fréquence de Staphylococcus spp. résistants à la méthicilline (MRS) isolés de chevaux admis à un hôpital d'enseignement vétérinaire au Québec entre 2008 et 2018, étudier les patrons de résistance aux antimicrobiens (AMR) et évalué la distribution de MRS et de Staphylococcus spp, sensible à la méthicilline (MSS) par site corporel. Durant la période visée, 311 Staphylococcus spp. furent isolés de 273 chevaux et 127 de ces isolats furent soumis à un test de sensibilité aux antimicrobiens. De ces 127 isolats, 24 (18,9 %) étaient de MRS, et parmi les S. aureus (n = 76), 19 (25 %) étaient des MRS. Les probabilités de détecter un MRS augmentaient (25 %) chaque année [intervalle de confiance 95 % (CI) (1 % à 55 %), P = 0,039]. Les fréquences les plus élevées de résistance étaient envers la tétracycline et la gentamycine. Parmi les isolats de MRS, 12 % étaient sensibles à la tétracycline et à la gentamycine. Les sites corporels les plus souvent échantillonnés étaient les « tissus mous ¼. Il n'y avait pas de différence significative (P = 0,93) entre les MRS et les MSS en ce qui a trait à la distribution selon les sites corporels.(Traduit par Dr Serge Messier).

Cryptococcus gattii pneumonia in an adult horse which had travelled in an endemic area.

A gelding from eastern Canada was presented for cough and exercise intolerance 14 months after it had travelled on Vancouver Island. Cryptococcus gattii pneumonia was diagnosed based on cytology, antigen titers, and polymerase chain reaction (PCR). The horse was treated with fluconazole for 10 months. Delayed C. gattii infection can occur after travel in an endemic area.

Pneumonie à Cryptococcus gattii chez un cheval adulte ayant voyagé dans une région endémique. Un cheval hongre de l'est canadien fut présenté pour de la toux et de l'intolérance à l'exercice 14 mois après avoir voyagé sur l'Île de Vancouver. Une pneumonie à Cryptococcus gattii fut diagnostiquée sur la base de la cytologie, des titres antigéniques, et de la réaction d'amplification en chaîne par la polymérase (PCR). Le cheval fut traité avec du fluconazole pendant 10 mois. Une infection à retardement par C. gattii peut survenir à la suite d'un voyage dans une région endémique.(Traduit par Dr Serge Messier).

Whole genome sequencing of methicillin-resistant and methicillin-sensitive Staphylococcus aureus isolated from 4 horses in a veterinary teaching hospital and its ambulatory service.

Genomic characterization was conducted on 2 methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from 2 horses hospitalized during an overlapping period of time and 2 methicillin-sensitive S. aureus (MSSA) strains isolated from 2 distinct horses. Phylogenetic proximity was traced and the genotypic and phenotypic characteristics of the antimicrobial resistance of the strains were compared. Whole genome sequencing of MRSA strains for this report was similar but differed from whole genome sequencing of MSSA strains. The MRSA strains were closely related, belonging to sequence type (ST) 612, spa type t1257, and SCCmec type IVd2B. The MSSA strains were also closely related, belonging to ST1660, spa type t3043, and having no detectable staphylococcal cassette chromosome mec elements. All MSRA and MSSA strains were Panton-Valentine leukocidin negative. There were discrepancies in the genotypic analysis and the antimicrobial susceptibility testing (phenotypic analysis) of MRSA strains for rifampin, trimethoprim-sulfamethoxazole, gentamicin, amikacin, and enrofloxacin.

La caractérisation génomique a été effectuée sur deux souches de Staphylococcus aureus résistantes à la méticilline (SARM) isolées de deux chevaux hospitalisés sur une période de chevauchement, et de deux S. aureus sensibles à la méticilline (SASM) isolés de deux chevaux distincts. Leur proximité phylogénétique a été retracée. Les caractéristiques génotypiques et phénotypiques de la résistance aux antimicrobiens de ces souches ont été comparées.Le séquençage complet du génome des souches de SARM pour ce rapport était similaire, mais différent du séquençage complet du génome des souches de SASM. Les souches de SARM étaient étroitement apparentées, appartenant à la séquence type (ST) 612, au spa type t1257 et au SCCmec type IVd2B. Les souches MSSA étaient étroitement apparentées appartenant au ST1660, spa type t3043 et aucun élément de la cassette contenant le gène mec n'a été détecté. Toutes les souches MSRA et MSSA étaient négatives pour la leucocidine Panton-Valentine. Il y avait des divergences entre l'analyse génotypique et les tests de sensibilité aux antimicrobiens (phénotype) des souches de SARM pour la rifampicine, le triméthoprime-sulfaméthoxazole, la gentamicine, l'amikacine et l'enrofloxacine.(Traduit par les auteurs).

Acute, subacute and chronic sequelae of horses accidentally exposed to monensin-contaminated feed.

BACKGROUND: Monensin is highly toxic to horses and inadvertent ingestion can result in cardiac injury and death. OBJECTIVES: To describe sequelae of monensin ingestion and to determine clinical predictors of outcome. STUDY DESIGN: Observational clinical study. METHODS: Physical examination, electrocardiogram and echocardiography were performed on 76 horses accidentally exposed to monensin-contaminated feed. Four horses were examined within 14 days of exposure (acute period), 29 horses were examined between 15 and 45 days post-exposure (subacute period) and 70 horses were examined 4-10 months after exposure (chronic period). Follow-up information was obtained for 56 horses by telephone interviews approximately 16 months after exposure. RESULTS: Cardiac abnormalities were detected in 4/4, 19/29 and 31/70 horses during the acute, subacute and chronic periods, respectively. Sixteen months post-exposure, 34 of the 64 horses (53%) for which the outcome was known had returned to their previous use, 13 (20%) were reported to be exercise intolerant, three (5%) were retired and 14 (22%) were dead (two deaths, 12 euthanasia). Thinning of the myocardium observed at any point in time was associated with a negative outcome. Heterogeneity of the myocardium observed in the acute/subacute period was associated with a negative outcome while subjective contractile intraventricular dyssynchrony, cardiac chamber dilation, decreased fractional shortening and multiple premature ventricular complexes observed in the chronic period were associated with a negative outcome. Some horses with significant changes associated with a negative outcome in the chronic phase still returned to their previous work. MAIN LIMITATIONS: No control group and only 27 horses were examined more than once. CONCLUSIONS: Clinical outcome of horses exposed to sublethal doses of monensin is highly variable. The presence of heterogeneity and thinning of the myocardium shortly after intoxication were associated with a negative outcome.

Influence of short distance transportation on tracheal bacterial content and lower airway cytology in horses.

The aim of this study was to determine the effects of short distance transportation on airway mucus, cytology and bacterial culture to identify potential biases in the diagnosis of airway diseases in referral centres. Eight healthy adult horses were studied using a prospective cross-over design. Mucus scores, tracheal wash (cytology, bacterial culture) and bronchoalveolar lavage fluid (BALF; cytology) were obtained while stabled and following 2.5 h transportation (with and without hay). Neutrophil counts, percentages and BALF neutrophilia frequency increased following transport without hay (P <0.05). No effect was observed on tracheal cytology and bacterial count (P > 0.05). BALF neutrophilia could develop solely as a result of transportation or due to interactions between repeated transports, ambient temperature, head position or other environmental factors.

Technical and physiological determinants of airway smooth muscle mass in endobronchial biopsy samples of asthmatic horses.

Morphometric analyses of endobronchial biopsies are commonly performed in asthma research but little is known about the technical and physiological parameters contributing to measurement variability. We investigated factors potentially affecting biopsy size, quality, and airway smooth muscle (ASM) content in heaves, an asthma-like disease of horses. Horses with heaves in clinical exacerbation (n = 6) or remission (n = 6) from the disease and six controls were studied using a crossover design. The effect of disease status, age, bronchodilation, biopsy forceps type, and carina size on total biopsy area (Atot), ASM area (AASM), ASM% (AASM/Atot), and histologic quality were assessed. Concordance among different measuring techniques was also assessed. Compared with other groups, horses with heaves in exacerbation yielded larger biopsies (P < 0.05). Better quality biopsies were obtained from carinae of small size compared with large ones (P = 0.02), and carina size and forceps type significantly affected the ASM content of the biopsy (interaction, P < 0.05). AASM increased with age only in heaves-affected horses (r = 0.9, P < 0.05), and ASM% was negatively correlated with pulmonary resistance at 5 Hz in heaves-affected horses (r = -0.74, P = 0.01), likely because of the increased thickness of the extracellular matrix layer in this group (P = 0.01). In conclusion, disease status, carina thickness, and the forceps used may significantly affect biopsy size, quality, and ASM content. Endobronchial biopsies are not appropriate samples for ASM quantification in heaves, and studies measuring ASM mass should not be compared when measuring techniques differ.