Equine post-anesthetic lameness. A retrospective study.

This research study investigated the incidence rate and contributing factors to post-anesthetic lameness in horses. Out of 655 horses that received anesthesia, 6.4% showed signs of lameness after anesthesia where hypotension and prolonged anesthesia were found to be significant factors.

Background and purpose

The researchers aimed to:

• Determine the incidence of post-anesthetic lameness in a large sample of horses over three years, as previous literature on the topic is quite sparse.
• Identify possible risk factors associated with this condition, with a focus on nineteen factors that had been suggested might increase the risk of post-anesthetic lameness.

Methodology

The research design involved:

• Analysing the medical records of 655 horses which had undergone 733 episodes of anesthesia. These animals were treated over a three-year period.
• Performing statistical analysis on the incidence of lameness after the administration of anesthesia.
• Evaluating nineteen variables, such as patient age, breed, physical condition, type of surgical procedure, duration of anesthesia, amongst others, that are proposed or reported to contribute to post-anesthetic lameness.

Findings

Key findings of the study included:

• Out of the 733 anesthetic episodes administered to the 655 horses, 6.4% resulted in instances of lameness after the anesthetic period. This indicates a relatively low incidence rate, but one that is still notable within the field.
• After evaluating nineteen potential factors, it was found that only two – hypotension (low blood pressure) and the duration of the anesthetic period – were statistically significant risk factors for inducing post-anesthetic lameness in horses.

Conclusion

Conclusions drawn from the study:

• Anesthetic management in horses should consider the duration of anesthesia and closely monitor the patient’s blood pressure during surgery to minimise the risk of post-anesthetic lameness.
• Further research in this area could focus on establishing a more detailed cause-and-effect relationship between these identified risk factors and post-anesthetic lameness, potentially leading to more effective preventative measures.