SURGERY OF THE LARGE INTESTINE IN THE HORSE

The common conditions which cause obstruction in the large intestine of the horse are presented. The etiology, diagnostic features, surgical treatment, and prognosis are discussed. The clinical workup, management of fluid therapy and anesthesia, surgical approaches, and post-operative care have been presented in other papers at this surgical forum and are not included here.     

COMPARATIVE ASSESSMENT OF TRANQUILLISERS IN THE HORSE

Measurement of heart rate appeared to be a useful method of quantitatively assessing fear and excitement in the horse. When 3 tranquillisers were assessed by this method, Xylazine and Azaperone were found to be more effective than Acepromazine in the horse. The findings based on heart rate were supported by observations of the animals' behaviour. Xylazine was most consistently effective with absence of undesirable side-effects in all 4 horses.     

INTERNAL FIXATION OF FRACTURES OF THE ULNA IN THE HORSE

SUMMARY Surgical repair of ulnar fracture was attempted in 7 horses. Of 6 animals in which tension band plates were used, 4 recovered, one was killed after implant failure and one died of respiratory failure during post-operative recovery. The treatment of one horse with a Steinman Pin and figure-8 tension band wire was unsuccessful. One horse with bilateral ulnar fractures was given only stall rest and it recovered.     

THE USE OF ELECTROCARDIOGRAPHY IN THE DIAGNOSIS OF POOR RACING PERFORMANCE IN THE HORSE

Electrocardiograms were reocrded from 153 racehorses and 10 Olympic three-day-event horses. The horses were then grouped into those presented for routine examination, those in which there was a complaint of poor performance, those going to the Montreal Olympics, and those with upper respiratory tract abnormalities. When the ECGs of the four groups were compared on the basis of detection of abnormality, it was found that 93.2% of the poor performance group showed abnormalities of various types. The routine examination group showed 21.1% of horses with abnormal ECGs, and over half of these have been followed to the point where it can be said they raced unsuccessfully. In particular, this applied to those horses with T wave abnormalities in 4 or more leads, and to those with intraatrial block. There were significant T wave changes in 50% of the Olympic horses, and 43.7% of horses with laryngeal hemiplegia showed abnormality. While it can be concluded that T wave changes are highly significant findings in an ECG, it is also true that modification of the training programme is a way of helping trainers to get the best out of horses which might otherwise have a serious limitation of their performance potential.     

SNAKEBITE IN THE HORSE

Four cases of snakebite in horses are presented. Diagnosis was made on clinical signs in all, plus fang punctures in 2 cases. Tiger snake antivenene was used in the treatment of 2 patients and these recovered rapidly. Of the 2 in which antivenene was not used, 1 severely affected horse died. The clinical signs which were observed were those of progressive general paralysis and were entirely referable to the neurotoxic component of the venom.     

SPLENECTOMY IN THE HORSE

SUMMARY Splenectomy was successfully performed on 2 aged horses to facilitate experimental studies of Babesia equi infection. Resection of part of the 17th rib provided the most acceptable approach and avoided many complications encountered on removing part of the 16th rib.