Effect of ketamine hydrochloride on the analgesic effects of tramadol hydrochloride in horses with signs of chronic laminitis-associated pain.

The research article focuses on studying the effects of ketamine hydrochloride when used in combination with tramadol hydrochloride in horses suffering from chronic laminitis-associated pain. It suggests that the analgesic effects of tramadol are significantly enhanced when administered with subanesthetic doses of ketamine.

Research Methods

• The study was conducted on 15 adult horses with chronic laminitis, owned by clients. A cross-over methodology was used in a randomized manner with a minimum two-month break between different treatments.
• The horses were given tramadol hydrochloride orally, every 12 hours for one week. In certain scenarios, ketamine was also administered intravenously for the initial three days of tramadol administration.
• Multiple parameters such as systemic blood pressure values, heart and respiratory rates, forelimb load and off-loading frequency, and plasma concentrations of tumor necrosis factor-α and thromboxane B(2) were assessed before (baseline), during (7 days) and after (3 days) each set of treatment.

Research Findings

• The findings revealed that, compared to the baseline data, the arterial blood pressure significantly decreased both during and after the combined tramadol-ketamine treatment. Such was not the case when tramadol was used alone.
• The frequency of forelimb off-loading significantly reduced in the initial three days of treatment with tramadol only. Post that, the frequency returned to its original level. However, when ketamine was introduced with tramadol, the off-loading frequency went down and remained so during and after the treatment.
• The force applied by the forelimb did not see any change with tramadol administration alone but increased when tramadol-ketamine combination was used.
• The plasma concentrations of tumor necrosis factor-α and thromboxane B(2) saw a significant drop with the tramadol-ketamine treatment. Tramadol alone did not bring about the same change.

Conclusion

• The study concludes that although tramadol provided limited relief to the horses with chronic laminitis, its analgesic effects were significantly enhanced when combined with subanesthetic doses of ketamine.