Multi-Centered Field Evaluation of a Salmonella spp. Point-of-Care PCR Assay Using Equine Feces and Environmental Samples.

The introduction of microfluidic card technology has opened the field for rapid point-of-care (POC) molecular assays, including fecal and environmental Salmonella spp. testing. The purpose of this study was to evaluate a novel POC PCR assay for the detection of Salmonella spp. in feces and environmental samples. A total of 143 fecal samples and 132 environmental samples were collected for POC PCR Salmonella spp. testing as well as qPCR testing. Each sample was inoculated into selenite broth and incubated for 18 to 24 hours. For the POC PCR assay, 14 µl of selenite broth were mixed with 126 µl of PCR reaction mix and pipetted into a microfluidic test card targeting the invA and ttrC gene of Salmonella enterica. For qPCR analysis, 200 µl of the selenite broth were processed for DNA purification and Salmonella spp. testing targeting the invA gene. The overall agreement between the POC PCR Salmonella spp. assay and qPCR assay was 88.1% for feces and 97.0% for environmental samples. Strong agreement and short turn-around-time make the POC device the first molecular diagnostic platform allowing detection of Salmonella spp. in a hospital setting without having to ship out samples to a veterinary diagnostic laboratory. The availability of an accurate POC PCR assay for the detection of Salmonella spp. will enhance the diagnostic capability of equine veterinarians to timely support a diagnosis of salmonellosis and also monitor the environment in order to reduce the risk of nosocomial infections.

Lipid peroxidation biomarkers for evaluating oxidative stress in equine neuroaxonal dystrophy.

BACKGROUND: Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (eNAD/EDM) is a neurodegenerative disorder affecting genetically predisposed foals maintained on an α-tocopherol (α-TOH) deficient diet. Currently no antemortem diagnostic test for eNAD/EDM is available. HYPOTHESIS: Because α-TOH deficiency is associated with increased lipid peroxidation, it was hypothesized that F2 -isoprostanes (F2 IsoP), F4 -neuroprostanes (F4 NP) and oxysterols derived from free radical oxidation would be increased in the cerebrospinal fluid (CSF) and neural tissue of eNAD/EDM affected horses and could serve as potential biomarkers for disease. ANIMALS: Isoprostane Study A: 14 Quarter horse foals (10 healthy foals and 4 eNAD/EDM affected foals) at 1 and 6 months of age. Isoprostane Study B: 17 eNAD/EDM affected and 10 unaffected horses ≥ 1-4 years of age. Oxysterol study: eNAD/EDM affected (n = 14, serum; n = 11, CSF; n = 10, spinal cord [SC]) and unaffected horses 1-4 years of age (n = 12, serum; n = 10, CSF; n = 7, SC). PROCEDURES: Cerebrospinal fluid [F2 IsoP] and [F4 NP] were assessed using gas chromatography-negative ion chemical ionization mass spectrometry. Serum, CSF, and cervical SC [oxysterols] were quantified using high performance liquid chromatography mass spectrometry. Results were compared with respective α-TOH concentrations. RESULTS: Spinal cord [7-ketocholesterol], [7-hydroxycholesterol], and [7-keto-27-hydrocholesterol] were higher in eNAD/EDM horses whereas [24-ketocholesterol] was lower. No significant difference was found in CSF [F2 IsoP] and [F4 NP], serum [oxysterols] and CSF [oxysterols] between eNAD/EDM affected and unaffected horses. No correlation was found between [F2 IsoP], [F4 NP], or [oxysterols] and respective [α-TOH]. CONCLUSIONS AND CLINICAL IMPORTANCE: In the SC, targeted markers of cholesterol oxidation were significantly increased in horses with eNAD/EDM.

Sialolithiasis in horses: A retrospective study of 25 cases (2002-2013).

This study evaluated outcomes of surgical treatment of equine sialolithiasis, highlighting cases involving the proximal parotid salivary duct. Sialoliths in the proximal parotid duct were difficult to identify radiographically and more frequently associated with draining tracts and sialadenitis compared with sialoliths in the distal parotid duct. Ultrasonography confirmed the diagnosis of sialolithiasis in all cases in which there was no radiographic evidence of a sialolith. All cases of proximal parotid duct sialolithiasis required transcutaneous removal. A longer duration of illness was observed in cases of proximal parotid duct sialolithiasis compared with cases involving the distal parotid duct, and in cases requiring transcutaneous removal compared with cases requiring transoral removal. Recurrence of sialolithiasis was documented in 24% of cases, all of which were located in the distal parotid duct. The average time to recurrence was 2.8 years.

Sialolithiase chez les chevaux : une étude rétrospective de 25 cas (2002­2013). Cette étude a évalué les résultats du traitement chirurgical de la sialolithiase équine et a mis en lumière des cas touchant le canal salivaire parotidien proximal. Les sialolithes du canal de Sténon étaient difficiles à identifier par radiographie et sont plus fréquemment associés à des faisceaux de drainage et à la sialadénite par opposition à des sialolithes dans le canal de Sténon distal. L'échographie a confirmé le diagnostic de sialolithiase dans tous les cas où il y avait des preuves radiographiques d'un sialolithe. Tous les cas de sialolithiase du canal salivaire parotidien proximal ont exigé une ablation transcutanée. Une plus longue durée de la maladie a été observée dans les cas de sialothiase du canal salivaire parotidien proximal par opposition aux cas touchant le canal de Sténon distal et, dans les cas exigeant l'ablation transcutanée par opposition aux cas exigeant l'enlèvement transoral. La récurrence de la sialolithiase a été documentée dans 24 % des cas et ils étaient tous situés dans le canal salivaire distal. Le délai moyen avant la récurrence était de 2,8 ans.(Traduit par Isabelle Vallières).

Primary gastric rupture in 47 horses (1995-2011).

The purpose of this retrospective case-control study was to identify factors associated with primary gastric rupture and to investigate if there were differences between etiologies of primary gastric rupture. Compared to the general colic population, Quarter horses were under-represented and Friesians and draft breeds were over-represented in 47 cases of primary gastric ruptures. Horses with primary gastric rupture typically presented with severe clinical and clinicopathological derangements. There were 24 idiopathic gastric ruptures, 20 gastric impaction associated ruptures, and 3 perforating gastric ulcers. Thoroughbred horses were over-represented in the idiopathic gastric rupture group compared to other breeds and etiologies. This study suggests the presence of important breed predispositions for development of gastric rupture. Further study is necessary to identify if these predispositions are associated with management factors or breed-specific disorders.

Rupture gastrique primaire chez 497 chevaux (1995­2011). Le but de cette étude rétrospective de cas témoins était d'identifier les facteurs associés à la rupture gastrique primaire et de faire une enquête afin de déterminer s'il y avait des différences entre les étiologies de la rupture gastrique primaire. Comparativement à la population générale de coliques, les chevaux Quarter horse étaient sous-représentés et les Frisons et les races de trait étaient surreprésentées dans 47 cas de ruptures gastriques primaires. Les chevaux atteints de rupture gastrique primaire étaient présentés avec de graves dérangements cliniques et clinicopathologiques. Il y avait 24 ruptures gastriques idiopathiques, 20 ruptures associées à l'impaction gastrique et 3 perforations ulcéreuses gastriques. Les chevaux pur-sang étaient surreprésentés dans le groupe des ruptures gastriques idiopathiques comparativement à d'autres races et étiologies. Cette étude suggère la présence de prédispositions importantes des races pour le développement de la rupture gastrique. De nouvelles études sont nécessaires pour identifier si ces prédispositions sont associées aux facteurs de gestion ou à des troubles spécifiques aux races.(Traduit par Isabelle Vallières).

Hemorrhage and blood loss-induced anemia associated with an acquired coagulation factor VIII inhibitor in a Thoroughbred mare.

CASE DESCRIPTION: A 23-year-old Thoroughbred mare was evaluated because of a coagulopathy causing hemoperitoneum, hematomas, and signs of blood loss-induced anemia. CLINICAL FINDINGS: The mare had tachycardia, pallor, hypoperfusion, and a large mass in the right flank. The mass was further characterized ultrasonographically as an extensive hematoma in the body wall with associated hemoabdomen. Coagulation testing revealed persistent, specific prolongation of the activated partial thromboplastin time (> 100 seconds; reference interval, 24 to 44 seconds) attributable to severe factor VIII deficiency (12%; reference interval, 50% to 200%). On the basis of the horse's age, lack of previous signs of a bleeding diathesis, and subsequent quantification of plasma factor VIII inhibitory activity (Bethesda assay titer, 2.7 Bethesda units/mL), acquired hemophilia A was diagnosed. The medical history did not reveal risk factors or underlying diseases; thus, the development of inhibitory antibodies against factor VIII was considered to be idiopathic. TREATMENT AND OUTCOME: The mare was treated with 2 transfusions of fresh whole blood and fresh-frozen plasma. Immunosuppressive treatment consisting of dexamethasone and azathioprine was initiated. Factor VIII deficiency and signs of coagulopathy resolved, and the inhibitory antibody titer decreased. The mare remained healthy with no relapse for at least 1 year after treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Horses may develop inhibitory antibodies against factor VIII that cause acquired hemophilia A. A treatment strategy combining transfusions of whole blood and fresh-frozen plasma and administration of immunosuppressive agents was effective and induced sustained remission for at least 1 year in the mare described here.

Pemphigus vulgaris in a Welsh pony stallion: case report and demonstration of antidesmoglein autoantibodies.

HYPOTHESIS/OBJECTIVES: To describe the clinical, histological and immunological findings of an equine case of pemphigus vulgaris, including the demonstration of antidesmoglein (anti-Dsg) autoantibodies. CASE REPORT: The diagnosis of pemphigus vulgaris was confirmed in a 9-year-old Welsh pony stallion with both direct and indirect immunofluorescence and immunoprecipitation studies, the latter identifying circulating anti-Dsg3 IgG. Treatment with immunosuppressive medications was initiated. Lesions were seen in the perineal area, sheath, mane, tail, eyelids, coronary bands and mucosa of the mouth and oesophagus. Initial corticosteroid treatment improved the clinical signs, but the onset of laminitis necessitated a reduction in dosage, which was associated with a recurrence of lesions and development of oral ulcers. A corneal ulcer developed after 60 days of treatment. Despite treatment with azathioprine, gold salts and dapsone, the disease progressed and the pony was euthanized. Postmortem examination showed additional lesions of the cardia of the stomach. CONCLUSIONS AND CLINICAL IMPORTANCE: Pemphigus vulgaris is rarely diagnosed in equids. We describe a case that was substantiated by the demonstration of anti-Dsg3 IgG. Response to treatment was poor, with the best response to high doses of prednisolone. Equine pemphigus vulgaris is likely to carry a poor prognosis and if there is no response to treatment, humane euthanasia is warranted.

Electrophysiological studies in American Quarter horses with neuroaxonal dystrophy.

OBJECTIVE: Neuroaxonal dystrophy (NAD) is a disease characterized by the sudden onset of neurologic signs in horses ranging from 4 to 36 months of age. Equine degenerative myeloencephalopathy (EDM), a disease that has been associated with low vitamin E concentrations, is considered a more advanced form of NAD. The objective of this report is to describe the electrophysiological features of NAD/EDM in American Quarter horses (QHs). HORSES: Six NAD/EDM-affected QHs and six unaffected QHs were evaluated by ophthalmic examination and electroretinography. Five of the NAD/EDM-affected QH and five unaffected QHs were also evaluated by electroencephalography (EEG). RESULTS: Ophthalmic examination, ERGs, and EEGs were unremarkable in NAD/EDM cases. CONCLUSIONS: Neuroaxonal dystrophy/EDM does not appear to cause clinical signs of ocular disease or functional ERG/EEG deficits in QHs.