T. Rajagopal and colleagues (2022) examined the reproductive behaviors and urinary volatiles of the Rajapalayam breed, a South Indian sighthound renowned for guarding and hunting. The researchers collected urine samples from females across different phases of the estrous cycle and exposed stud males to these samples.
Behavioral observations revealed that males exhibited significantly higher rates of investigation, mounting, pre-mount contact, and penile erection when exposed to estrus-phase urine compared with pro-estrus or post-estrus samples. In contrast, males showed little to no sexual response toward post-estrus urine.
Gas chromatography–mass spectrometry identified around 30 volatile compounds across the estrous cycle, with several being estrus-specific. Among these, (E)-9-methyl-7-undecenoic acid proved the most effective at eliciting sexual behaviors in male dogs, confirming its role as a dominant urinary sex pheromone. Synthetic mixtures replicating estrus urine also successfully provoked male attraction.
These findings demonstrate that female Rajapalayam dogs use chemical signals in urine to communicate reproductive status. The authors propose that monitoring estrus-specific urinary volatiles may offer a non-invasive method for accurately timing mating in breeding programs.
Source: Rajagopal, T., Dhivya, A., Ponmanickam, P., Abdulkader, M. A., & Archunan, G. (2022). Identification of urinary sex pheromones in female Rajapalayam breed dog and their influence on stud male reproductive behaviour. Journal: Journal of Applied Biology & Biotechnology. Publication Date: 2022. Authors: T. Rajagopal et al.
