The aim of this study was to evaluate the suitability of synthetic bitch sex pheromones (Eau’ De Estrus®, Synbiotics USA) for the stimulation of the reproductive reflexes in adult male dogs. In experiment I: anoestral bitches were applied synthetic (n=6) or natural (n=6) pheromones and their attractiveness was compared to the attractiveness of bitches in natural oestrus, In experiment II: swabs socked in natural estrual discharge or Eau D’Estrus were presented to male dogs and behavioral arousal (Exp. II a) and changes in blood flow in the penile artery reflecting erection (Exp. II b) were recorded. In experiment III the time dedicated for sniffing in experimental dogs was analyzed in relation to the type of attractant presented (natural estrual discharge or Eau D’Estrus). In all three experiments we observed the signs of sexual arousal, increased blood flow in the penile artery and increased time of sniffing only with natural pheromones. No signs of excitation or changes in penis perfusion were noted after the use of artificial pheromones. Our results did not support the suitability of Eau D’Estrus for male dog sexual stimulation.