Ex vivo comparison of barbed sutures for pelvic flexure enterotomy in horses.

OBJECTIVE: To evaluate two different barbed sutures for closure of pelvic flexure enterotomies and compare results achieved with two previously described closure techniques. STUDY DESIGN: Ex vivo. SAMPLE POPULATION: Twenty-four fresh cadaver adult equine large colons. METHODS: Cadavers were randomly assigned to four closure groups (n = 6 each group): single-layer absorbable suture, double-layer absorbable suture, single-layer unidirectional barbed suture, or single-layer bidirectional barbed suture. Construction time, luminal reduction (percentage), bursting pressure, and method of failure were measured. Cost, leakage, exposed suture, and general appearance were recorded. Comparisons were performed with one-way analysis of variance and post hoc Bonferroni test (P < .05). RESULTS: Double-layer absorbable closure had the highest bursting pressure (mean = 178.5 mm Hg, SD = 9.79, P < .001) but took more time (P = .001) compared with all other groups. The construction time of both barbed suture closures did not differ from the single-layer closure (P > .06). Bursting strengths of both unidirectional (mean = 91.6 mm Hg, SD = 5.57) and bidirectional (mean = 87.5 mm Hg, SD = 8.69) barbed sutures were lower (P > .006 for both) than those of both single- (mean = 117.6 mm Hg, SD = 11.69) and double-layer (mean = 178.5 mm Hg, SD = 9.79) closures. Unidirectional barbed suture closure had a reduction in lumen diameter (P = .004) compared with bidirectional and single-layer closures. CONCLUSION: Enterotomy closures with the two different barbed suture patterns were comparable in bursting strength and construction time. However, the barbed suture patterns had lower bursting strength compared with traditional single- and double-layer closures. Unidirectional barbed suture closure also reduced lumen diameter. CLINICAL SIGNIFICANCE: Closure of a large colon enterotomy with barbed suture patterns may be less secure than single- and double-layer suture closure.

Diagnosis and treatment of dynamic collapse of the cricotracheal ligament in thoroughbred racehorses.

OBJECTIVE: To describe (1) diagnosis of dynamic collapse of the cricotracheal ligament in a group of horses and (2) treatment and outcome of affected horses. STUDY DESIGN: Retrospective case series. ANIMALS: Thoroughbred horses (n = 8). METHODS: Of 600 over ground dynamic endoscopic examinations performed, 8 Thoroughbred horses had cricotracheal ligament collapse (CTLC); 5 were 2 years old and in early training and 2 were mature horses in full work. CTLC was diagnosed if circumferential collapse of the cricotracheal ligament was identified during exercise. Seven horses had repeat endoscopic examination. Two horses unresponsive to conservative management were treated surgically. RESULTS: Multiple abnormalities of the upper portion of the respiratory tract were identified along with CTLC in all five 2-year-old horses and resolution of CTLC was observed after treatment for upper airway inflammation. No concurrent respiratory abnormality was identified in the 2 mature horses. Surgical reduction of the cricotracheal space and imbrication of the cricotracheal ligament of these 2 horses resulted in resolution of clinical signs of CTLC. CONCLUSIONS: CTLC is a rare cause of dynamic obstruction in Thoroughbred racehorses. Resolution may occur after adaptation to training and after inflammation of the respiratory tract is resolved, but for horses with persistent CTLC, surgical reduction of the cricotracheal space and imbrication of the cricotracheal ligament may result in resolution of clinical signs.

Bovine papillomavirus gene expression and inflammatory pathway activation vary between equine sarcoid tumour subtypes.

Equine sarcoids are common non-metastasising skin tumours in horses, associated with bovine papillomavirus (BPV) infection. Six subtypes are recognised (occult, verrucose, nodular, fibroblastic, mixed and malevolent lesions), with variable clinical behaviour. The pathophysiology underlying varying tumour phenotype is poorly understood, and previous data on associations with viral load have been conflicting. To better understand this clinical variation, we investigated associations between tumour subtype and viral load, viral early protein gene expression, and expression of 10 host genes by quantitative polymerase chain reaction in 27 sarcoids and 5 normal skin samples. Viral DNA copy number did not differ between subtypes but was significantly higher in animals with fewer tumours. Expression of BPV E2 and E6 was higher in occult lesions compared to fibroblastic or nodular lesions, while E5 expression was higher in previously-treated lesions. Of the host genes, only IL6 and IL1B differed between subtypes, with higher expression in fibroblastic lesions, while IL10 and CCL5 were elevated compared to skin in all lesion types, and elevations in TNF and TGFB1 were significant for occult lesions only. Expression of TLR9, ATR, VEGFA and PTGS2 in sarcoids was not significantly different from normal skin, suggesting differences between BPV and human papillomavirus tumorigenesis. Results for BPV viral load and gene expression differed from previous reports and are insufficient to explain the spectrum of tumour phenotypes. Activation of both pro-inflammatory and anti-inflammatory immune pathways in sarcoids could influence tumour growth and effective immune responses, and the contribution of specific infiltrating immune cells requires further investigation.

Environmental surveillance identifies multiple introductions of MRSA CC398 in an Equine Veterinary Hospital in the UK, 2011-2016.

Bacterial environmental and surgical site infection (SSI) surveillance was implemented from 2011-2016 in a UK Equine Referral Veterinary Hospital and identified 81 methicillin-resistant Staphylococcus aureus (MRSA) isolates. A cluster of MRSA SSIs occurred in early 2016 with the isolates confirmed as ST398 by multilocus sequence typing (MLST), which prompted retrospective analysis of all MRSA isolates obtained from the environment (n = 62), SSIs (n = 13) and hand plates (n = 6) in the past five years. Sixty five of these isolates were typed to CC398 and a selection of these (n = 38) were further characterised for resistance and virulence genes, SCCmec and spa typing. Overall, MRSA was identified in 62/540 (11.5%) of environmental samples, 6/81 of the hand-plates (7.4%) and 13/208 of the SSIs (6.3%). spa t011 was the most frequent (24/38) and Based Upon Repeat Pattern (BURP) analysis identified spa t011 as one of the two group founders of the main spa CC identified across the five years (spa CC011/3423). However, 3 singletons (t073, t786, t064) were also identified suggesting separate introductions into the hospital environment. This long-term MRSA surveillance study revealed multiple introductions of MRSA CC398 in a UK Equine Hospital, identifying an emerging zoonotic pathogen so far only sporadically recorded in the UK.