Discussion

Aim: To describe a case series of horses at Rossdales Equine
Hospital (REH) that had standing resection of dorsal spinous processes (DSPs) as a treatment for overriding or impinging (OI)- DSPs. Methods: Inclusion criteria consisted of: 1) horses referred to REH's surgical department following diagnosis of clinically significant OI-DSPs; 2) subsequent DSP resection under standing sedation and local anaesthesia, by R.J.P. between 2005 and 2011. Clinical data were collected from hospital records. Results: Eighteen horses satisfied the inclusion criteria. There were equal numbers of Thoroughbred and Thoroughbred-cross (n = 8, 45%) and warm-blooded breeds (n = 8, 45%). Median age of these horses was 8.5 years (range 5 - 15). The most common number of DSPs removed was 2 (n = 7, 39%; range 1 - 4). A total of 47 DSPs were removed; the most commonly resected DSP was T16 (n = 11; 23.4%), followed by T14 (n = 10; 21.3%). The most cranial DSP removed in any case was T12, the most caudal was L2. Two horses had concurrent surgical procedures performed alongside standing DSP resection (bilateral stifle arthroscopy and cutaneous nodule removal). Thirteen horses were re-examined at REH, at a median 13.9 weeks post operatively (range 4.4 - 49.3). At re- examination 10 of these (77%) were recovering uneventfully. Conclusions: These results show no disadvantages of DSP resection under standing sedation and local anaesthesia compared to results published previous following resection under general anaesthesia. Practical significance: For horses with painful OI-DSPs that are refractory to medical management, resection of those DSPs under general anaesthesia has been shown to offer a positive post operative prognosis. However there are few follow-up data published for horses that have had standing surgical removal of DSPs. The advantages of operating in the standing horse include increased intraoperative visualisation, decreased intraoperative haemorrhage and avoidance of the inherent risks of general anaesthesia in the equine patient. Acknowledgements: Polly Compston was supported by Margaret Giffen Trust.