Effect of administration of prostaglandin F2alpha or presence of an estrous teaser bitch on characteristics of the canine ejaculate

Semen was collected from eight dogs after SC administration of 0.1 mg/kg PGF2alpha or 0.6 mL 0.9% NaCl solution 15 min prior to collection in the presence or absence of an estrous teaser bitch (switchback design; all dogs given all four treatments in random sequence). There were more spermatozoa (P = 0.02) in ejaculates collected after administration of PGF2alpha in the presence of an estrous teaser bitch ((852 ± 736) × 10⁶, mean ± S.D.) than in ejaculates collected in saline-treated dogs in the absence of a teaser bitch ((371 ± 620) × 10⁶). However, the number of spermatozoa in the ejaculate of dogs given PGF2alpha in the absence of a teaser bitch and in dogs given saline in the presence of a teaser bitch ((556 ± 494 and 600 ± 622) × 10⁶, respectively) were not significantly different from each other or from the other two groups. The percentage of morphologically normal spermatozoa did not vary by treatment (P = 0.51). In conclusion, treatment with PGF2alpha and presence of a teaser bitch had an additive effect on the number of spermatozoa. This, coupled with relatively minor side-effects, suggests this is a useful technique to increase number of spermatozoa in a single canine ejaculate.