The most common events experienced by racehorses on race-day were relatively minor and not career-ending. Although more severe bone, joint, tendon and ligament injuries were less common, they had a greater impact on whether the outcome of the event was fatal.

Background: Atrial fibrillation (AF) impacts performance and horse and jockey safety. Understanding the outcomes of AF identified postrace will better inform regulatory policy. Hypothesis/Objectives: To investigate the outcomes after episodes of AF identified postrace and determine whether affected horses are at increased risk of additional episodes compared to the general racing population. Animals: Total of 4684 Thoroughbred racehorses. Methods: Race records for Thoroughbred horses racing in Hong Kong from 2007 to 2017 were reviewed. Horses that performed below expectation were examined by cardiac auscultation and ECG. Incidence and recurrence of AF were compared between horses with and without a history of AF and between horses with paroxysmal and persistent episodes using Fisher's exact test. Results: There were 96 135 race starts during the study. Atrial fibrillation was identified in 4.9% of horses, with an overall incidence of 2.7 episodes per 1000 starts. The incidence of AF in horses after any previous episode (12.8 per 1000 starts) was higher than for horses with no previous episode (2.4 per 1000 starts; odds ratio [OR], 5.3; 95% confidence interval [CI], 3.8-7.6). Recurrence was seen in 64% of horses previously treated for persistent AF, which was higher than recurrence in horses with paroxysmal AF (23%; OR, 5.9; 95% CI, 1.6-21.2). Median duration between episodes was 343 days (range, 34-1065). Conclusions and Clinical Importance: Thoroughbreds are at increased risk of recurrent AF after both paroxysmal and persistent episodes, but the duration of time between episodes varies widely. These findings support a substantial burden of AF among individual Thoroughbred racehorses.

of Gram-positive, and 23/44 (43%) of Gram-negative bacteria were susceptible to trimethoprim-2 sulfonamide. Of 126 isolates, 33 (26%) were MDR; >1 isolate with MDR was cultured from 24/64 (38%) foals, and ≥2 isolates with MDR were recovered from 8/64 (13%) foals.CONCLUSIONS: Multi-drug resistance, including resistance to commonly used antimicrobials, was found in bacterial isolates from foals in New Zealand.CLINICAL RELEVANCE: The results of this study are of concern from a treatment perspective as they indicate a potential for antimicrobial treatment failure. For future surveillance of AMR and the creation of national guidelines, it is important to record more data on samples submitted for bacterial culture.

Objective To compare the bursting strength and failure mode of ventral midline celiotomy closed with a simple continuous suture pattern with 1 of 2 knot combinations, a novel self‐locking knot combination of a forwarder start with an Aberdeen end knot (F‐A) and a traditional combination of a surgeon's start with a surgeon's end knot (S‐S). Study design Ex vivo experimental. Sample population Equine cadavers (n = 14). Methods A 20‐cm ventral midline celiotomy was created in 14 equine cadavers. Horses were assigned to celiotomy closure with an F‐A or S‐S knot combination. Prior to closure, a 200‐L inflatable bladder was placed in the abdomen and then insufflated until failure of the celiotomy closure. The horses’ signalment, weight, breed, and age, as well as knot combination type, mode of failure, closure time, and bursting strength (mm Hg) were recorded. Results The median bursting strength was significantly greater when incisions were closed with the F‐A knot combination (388 mm Hg) compared with the S‐S knot combination (290 mm Hg) (P = .035). Most incisions failed along the fascia when closed with F‐A combinations and at the knot when closed with S‐S combinations. Conclusion The bursting strength of ventral midline incisions in equine cadavers was increased by an average of 25% when closed with the self‐locking F‐A knot combination. Clinical significance Closing ventral midline celiotomies with an F‐A knot combination may provide a more secure closure than the traditional S‐S knot combination. Additional in vivo investigation is required prior to recommending this closure in clinical cases.