Time-dependent changes in cardiovascular function during copulatory behavior induced by the hand method in the male...

Area of Science:

• Veterinary Physiology
• Animal Reproduction

Background:

• Ejaculation in male dogs comprises three distinct fractions.
• Understanding the physiological responses during canine reproduction is crucial for breeding programs.

Purpose of the Study:

• To investigate sympathetic nerve activity during induced ejaculation in male dogs.
• To measure heart rate and plasma catecholamine levels during copulatory behavior.

Main Methods:

• Male dogs underwent induced ejaculation using the hand method.
• Heart rate, plasma noradrenaline, and plasma adrenaline were sequentially measured.

Main Results:

• Heart rate peaked during mounting (195.2 ± 8.2 beats/min) but returned to resting levels post-ejaculation.
• Plasma noradrenaline and adrenaline levels did not significantly differ from resting values.
• A slight, non-significant peak in plasma noradrenaline was observed during the third ejaculatory fraction.

Conclusions:

• Sustained sympathetic nerve excitation during canine penile erection and ejaculation is unlikely.
• Parasympathetic nerve activation may play a role during erection and ejaculation in male dogs.