Artificial insemination with frozen semen in dogs: a retrospective study of 10 years using a non-surgical approach.

Abstract From 1994 to 2003, a total of 526 bitches of 99 different breeds were artificially inseminated in 685 estrus cycles with domestic ( n  = 353) or imported ( n  = 332) frozen-thawed semen from 368 males. The overall whelping rate was 73.1% and mean (±S.E.M.) litter size 5.7 ± 0.1 pups. The whelping rate was higher after intrauterine insemination (75.0%; n  = 665) than after intravaginal insemination (10.0%, n  = 20; P n  = 559; P P n  = 61). Two inseminations ( n  = 384) yielded a higher whelping rate ( P P n  = 241), 78.1% and 6.0 ± 0.2 and 70.5% and 5.1 ± 0.2, respectively. For inseminations performed at the optimal time, however, the whelping rate was not significantly different for bitches inseminated twice (79.3%, n  = 358) versus once (76.8%, n  = 168), but the litter size was larger (6.0 ± 0.2 and 5.3 ± 0.3). Semen classified as of poor quality (progressive motility 20%) resulted in a lower whelping rate ( P n  = 50) had a smaller litter size (3.9 ± 0.3; P n  = 94], large [5.9 ± 0.2, n  = 295] or giant breeds [6.1 ± 0.5, n  = 62] [ P P P n  = 30) than for bitches with larger litters (60.5 ± 0.1 days, n  = 177). These results show the potential of transcervical intrauterine insemination for routine artificial insemination in dogs. The results with frozen semen inseminations were optimised by inseminating bitches ≤6 years old 2 and 3 days after ovulation with semen of good quality from males ≤8 years old.