Influence of transvaginal ultrasound-guided follicular punctures in the mare on heart rate, respiratory rate, facial expression changes, and salivary cortisol as pain scoring.

The study investigates the influence of transvaginal ultrasound-guided follicular punctures (a veterinary process that involves needle aspiration of an ovary through the vaginal wall) in horses on several physiological and behavioural parameters such as heart rate, respiratory rate, facial expressions, and salivary cortisol concentration.

Understanding the Research Framework

• The primary objective of this study was to assess the impact of transvaginal ultrasound-guided follicular punctures on mares’ (adult female horses’) stress, pain, and well-being. These punctures are largely used in the equine industry for either diagnostic purposes, research or even commercial applications.
• The research has been conducted on 21 pony mares, which are divided into two groups – a test group where 11 mares underwent follicular aspirations, and a control group where 10 mares were treated and injected similarly but did not undergo follicular aspirations.
• Techniques like measurement of heart rate and breath rate, ear position, eyelid closure, facial muscle contraction, and salivary cortisol concentration were used for evaluating pain and stress before, during, and after the puncture process.

Key Findings

• Following sedative injection, both the tested and control mares showed signs of relaxation, as observed by changes in their ear position, eyelid closure and contraction of facial muscles. However, no significant difference was recorded between both groups.
• There were no marked changes in the salivary cortisol concentration during the puncture process, and no difference was observed between the tested and control mares at any moment.
• The breath rate remained unaffected throughout the process for both the tested and the control mares.
• The heart rate, however, increased significantly but temporarily when the needle was introduced into the ovary and was higher for the punctured mares than the control group. No other parameters investigated were affected at this time, suggesting the discomfort is minimal and temporary.

Conclusion and Recommendations

• The researchers concluded that the process of transvaginal ultrasound-guided follicular puncture causes only minimal and transient discomfort to the mares. However, they recommended improving analgesia during the needle introduction, possibly through a multimodal approach, as it was identified as a slightly more sensitive step.
• They also concluded that observing changes in facial expression and heart rate is a simple yet accurate way to assess pain and the overall well-being of mares.