Effect of Sildenafil (Viagra®) on Penile Erection and Semen Volume and Characteristics in Kangal Dogs

In this study, the effects of sildenafil administration on penile erection and semen volume and characteristics in Kangal dogs were studied. A total of 5 Kangal dogs, aging 3-6 years, and with a known fertility were used. In each application, sildenafil was administered orally at a dosage of 50 mg, 60 minutes prior to semen collection. Semen was collected 12 times at 3-day intervals by digital manipulation. After collected, semen was examined for volume (first, second, and third fractions), ejaculation time, and spermatological characteristics. Dogs were rested for 3 weeks after the last semen collection. Following the rest period, semen collection was experienced 12 times at 3-day intervals by digital manipulation without sildenafil application. Sildenafil administration enhanced the volume of the second and third fractions, compared to the non-sildenafil group (1.1 ml versus 0.7 ml and 11 ml versus 6 ml, respectively, P<0.05), and increased the total ejaculation time (11.8 minutes versus 7 minutes, P<0.05). On the other hand, there were no significant differences between the sildenafil and non-sildenafil groups for spermatological characteristics (P>0.05). As a conclusion, sildenafil could be used in dogs, having problems in response to digital manipulation, for penile erection and successful semen collection.