Evaluation of squeeze-induced somnolence in neonatal foals.

The research focuses on a study to determine if using a rope restraint on newborn foals would cause changes in their behavior, brain activity, and hormone levels that indicate sleep and pain relief.

Research Methods

A total of 8 healthy newborn foals were involved in this experiment. The foals became acclimated to the conditions of the experiment before they underwent a variety of assessments before, during, and/or after the times when a restraint device was used, which in this case was made from soft linen rope. These assessments included:

• Measures of heart and respiratory rates, and rectal temperature
• Measurements of the concentrations of β-endorphin and steroid hormones in the bloodstream
• Evaluation of mental and physical behavior
• Monitoring of brain activity patterns via electroencephalography
• Pain tolerance tests

Findings of the Research

According to the results, all foals appeared lively and displayed normal behavior prior to the use of the restraint. However, during the application of the rope restraint, the foals exhibited calm, sleepy behavior and rested in a sideways position. The measurements for heart rate, respiratory rate, and rectal temperature all decreased uniformly during the experiment. The EEG tests, which were only conducted in 3 foals, showed patterns indicative of slow-wave sleep typically found during deep sleep states. Hormone levels in the blood, including ACTH, dehydroepiandrosterone sulfate, and androstenedione, had a significant increase during the restraint application. The foals also exhibited an increased tolerance to pain during their restraint, but this change was not related to the levels of β-endorphin in the bloodstream.

Conclusions of the Study

The procedure involving the application of the restraint led to a decrease in heart and respiratory rates, as well as rectal temperature, for the newborn foals. The effects induced by the squeeze mechanism, termed as “squeeze-induced somnolence,” might resemble those caused by fetus compression while in the birth canal, leading to a decrease in voluntary activity. Further evaluations and studies need to be conducted to establish whether this technique could be implemented as a safe means to control newborn foals during minor procedures.