South African Equine Veterinary Association Congress 2015 Protea Hotel Stellenbosch
mortem evidence is generally required, and photographs taken with a digital camera can be
helpful.
In general, if a conscious horse has made no attempt to rise by 1 hour then humane destruction is
in most cases warranted. In horses displaying significant neurological compromise, euthanasia is
probably indicated if signs remain without improvement for 1 to 4 hours, or before if signs are
especially severe or deteriorate despite your treatment. Note however that the use of sedatives
may delay successful attempts to stand.
In a comatose or semicomatose animal and if circumstances allow, a more prolonged assessment
may be indicated: many horses that regain consciousness will do so within a few hours. More
aggressive treatment to limit the development of central nervous system oedema (e.g. 20%
mannitol, 0.5-1 g/kg IV) is warranted during this time as is systemic fluid therapy. Persistent
dilation and fixation of the pupils however carries a poor prognosis and suggests the probable
need for euthanasia. In rare and extenuating circumstances, (if attempted), a more prolonged
recovery (days) is possible; however management in such cases carries a number of additional
problems and should only be contemplated following particularly careful consultation with
owners, insurance companies and referral veterinary practices.
Moving a recumbent horse
On occasion it may be deemed necessary or appropriate to move a recumbent horse. For short
distances this can be performed via the drag mat in the conscious sedated animal with appropriate
restraint. Rarely, longer distance transportation in the horse ambulance may be better and more
safely accomplished with the animal anaesthetised. A combination of ketamine (2.2 mg/kg) and
diazepam (0.1 mg/kg) via an indwelling catheter for induction of anaesthesia in the already
sedated animal is appropriate. Maintenance of anaesthesia can be accomplished with „triple drip‟
(guaifenesin 100mg/ml; ketamine 2mg/ml and xylazine 1mg/ml in 5% dextrose) at 12ml/kg/hour.
References
Management of a recumbent horse (Chapter 7). J. Williams and S. Dyson. In: A guide to the management of
Emergencies at Equine Competitions. EVJ Ltd, Newmarket, 1996
Large Animal Neurology, A Handbook for Veterinary Clinicians. I.G. Mayhew. Lea & Febiger; Philadelphia, PA,
1989.
Anesthetic, cardiorespiratory, and metabolic effects of four intravenous anesthetic regimens induced in horses
immediately after maximal exercise. Hubbell et al. Am J Vet Res. 2000. Dec; 61 (12):1545-52.jmc
128