Gynaecological examinations via the rectum did not cause major stress in mares involved in an Austrian study.
Researchers Natascha Ille, Christine Aurich and Jörg Aurich set out to analyse the stress response of mares to the examinations based on salivary levels of the stress hormone cortisol, heart rate, and heart-rate variability.
The study team from the University of Veterinary Medicine, Vienna, used 21 horses with differing experiences to both transrectal palpation and ultrasonographic examination of the genital tract.
All mares were followed for three examinations and 13 mares for four examinations. Ten of the animals were examined every six hours and 11 at 24 to 48 hour intervals.
The researchers hypothesized that gynecological examination would cause a stress response which decreased with repeated examinations.
They found that heart rate increased slightly with gynaecological examination. The response did not change from examination 1 to 4, nor did it differ between experienced and inexperienced mares.
The increase in heart rate was higher in mares examined every six hours compared to those examined every 24 to 48 hours.
Heart-rate variability did not change while cortisol concentrations increased. The cortisol response was more pronounced in mares examined at six-hour intervals than in those examined every 24 to 48 hours, the study team wrote in the Journal of Equine Veterinary Science.
“In conclusion, transrectal examination of mares was not perceived as a major stressor but the response was influenced by examination frequency,” the trio reported.
Physiological stress responses of mares to gynecological examination in veterinary medicine
Natascha Ille, Christine Aurich, Jörg Aurich
The abstract of the study can be read here.