Unintentional intracarotid injections in the horse—15 cases (2010–2020)

Summary Background Intracarotid injections are a well‐recognised complication of jugular injections in the horse; however, little information is available about outcome and complications. Objectives The aim of this study was to describe venipuncture techniques and short‐ and longer‐term complications related to intracarotid injections. Study design Case series. Methods The survey was distributed through the American College of Veterinary Internal Medicine (ACVIM) mailing list and a veterinary social media site. Data collected in the questionnaire included injection technique, drug administered, personnel performing the injection, clinical signs and short‐ and longer‐term complications. Results Accidental intracarotid injections were most commonly performed by veterinarians (n = 9/13). The majority of reported accidental intracarotid injections occurred during routine sedation in healthy horses (n = 8/13) and occurred when the jugular vein was accessed at the middle jugular groove (n = 6/13). Most events occurred while using longer needles (1.5 inches; n = 10/13) of 20G calibre (n = 9/13), attached to the syringe (n = 11/13) and against jugular blood flow (n = 11/13). Short‐term injuries included superficial abrasions (n = 13/13) and cardiac ailments (3/13). One of the 15 horses described in this report died. Longer‐term complications were not reported for the remaining 14 horses. Main limitations Potential selection, recall and response bias and putative risk factors identified cannot be correlated with an increased risk of carotid injection without a control group. Conclusion Accidental intracarotid injections led to seizures but rarely resulted in death of the case. Premonitory clinical signs occurred while or soon after injection and can be used for early identification of this inadvertent injection and to establish safety measures for the horse and handlers.