Epidural administration of tiletamine/zolazepam in horses.

The research investigates the effects of using tiletamine/zolazepam, a type of anesthesia, administered epidurally in healthy horses. The findings indicate the substance raises the tolerance to pressure stimulation in horses and could be applicable for short-term moderate epidural analgesia, a method to relieve pain.

Research Methodology

• The study is a ‘Prospective, double-blind, randomized experimental study’ carried out on five adult, healthy horses which were sedated with xylazine. An epidural catheter was inserted after which a resting period of 48 hours was observed.
• The tiletamine/zolazepam was administered epidurally in two different doses, 0.5 mg kg(-1) (treatment I) and 1.0 mg kg(-1) (treatment II), each one week apart. The substance was diluted up to 5 mL in sterile water prior to administration.
• Physiological parameters assessed during the study included heart rate, respiratory rate, arterial blood pressure, and level of sedation. To assess the respiratory effects, blood samples from the carotid artery were taken before and after (60 and 240 minutes) administration.
• Analgesia was evaluated by applying a non-damaging stimulus with blunt-tipped forceps on the perineal area of the horses. The response to the stimuli was graded as complete, moderate, or absent.

Results of the Study

• The statistical analysis of the data showed there were no significant differences in cardiovascular and respiratory measurements between the treatments.
• Both doses resulted in sedation in the horses. For the higher dose (treatment II), there were notable variances from the baseline at 60, 75, and 90 minutes
• Both the treatment I and II doses brought about moderate analgesia and locomotor ataxia (loss of full control of bodily movements) among the horses.

Conclusions and Future Recommendations

• The key conclusion drawn from the results is that tiletamine/zolazepam, when administered epidurally, heightens the resistance to pressure stimulation in the perineal area of horses. As such, epidural tiletamine/zolazepam could be considered for providing short-term moderate epidural analgesia.
• However, since there are no established studies on the potential spinal toxicity of tiletamine/zolazepam (Telazol), the researchers caution that further studies would be prudent before this technique is recommended for clinical use.