High Embryonic Recovery Rates with In vivo and Ex vivo Techniques in the Bitch

Abstract

The embryonic collection techniques in dogs present a vast methodological variation and low recovery rates. The objectives were to compare and describe two techniques as to the recovery of canine embryos, on the 12th day after the first mating or artificial insemination. Embryos were recovered through uterine horn flushing in vivo, before performing the ovariohysterectomy (OHE) (Group 1; n = 9) or ex vivo, immediately after the OHE (Group 2; n = 9). In total, 43 and 47 embryonic structures were recovered in Groups 1 and 2, respectively. There was no significant difference (p > 0.05) between groups on recovery rates (72.8% and 81.0%, respectively). We inferred that both in vivo and ex vivo techniques allow a high rate of embryonic recovery; in the collection technique prior to the OHE, it is essential to carefully handle the reproductive system during the trans-surgical period and that the 12th day (D12) after the first mating/artificial insemination is an efficient option for the high recovery rate of morulae and blastocysts.

Post-thaw viability of in vivo-produced canine blastocysts cryopreserved by slow freezing

“…The average embryo recovery rate in this study (57.6%) seemed lower than our previous report (81.0%) [12], but was similar to results obtained with silver foxes (66.0%) [17]. Furthermore, there was also a greater blastocyst recovery in this study regarding the number of recovered embryos, as previously described [12]. Factors, such as, endometrial cystic hyperplasia [18], variations in plasma progesterone concentrations [19], or the presence of the embryos in the uterine tubes, instead of the uterine horns [12] may have affected the recovery rate.…”

“…However, there was a 50 to 90% recovery of the embryos in three dogs (18.7%), whereas in four others (25.0%), no embryo was recovered. The average embryo recovery rate in this study (57.6%) seemed lower than our previous report (81.0%) [12], but was similar to results obtained with silver foxes (66.0%) [17]. Furthermore, there was also a greater blastocyst recovery in this study regarding the number of recovered embryos, as previously described [12].…”

“…Embryo recoveries were performed by uterine flushing, using the ex vivo technique standardized in our laboratory [12], 12 days after first mating or AI. The anesthetic protocol used was 0.1 mg/kg IM acepromazine (Acepran 0.2%; Vetnil, Louveira, SP, Brasil), 7.5 mg/kg IM tiletamine/zolazepam (zoletil 50; Virbac Saúde Animal, São Paulo, SP, Brasil), and 5.0 mg/kg IV propofol (Propovan; Cristália, São Paulo, SP, Brasil) It was noteworthy that propofol was administered only after the uterus had been removed.…”

“…Briefly, bitches were subjected to an ovariohysterectomy. After the uterus was removed, each uterine horn was flushed three times using a total of 30 mL of Dulbecco's PBS (Nutricell, Campinas, SP, Brasil) [12]. The uterine flushes were immediately recovered into petri dishes.…”

“…After identification of embryos, they were transferred to disposable 35 ϫ 10 mm petri dishes, in PBS with 0.4% BSA (Nutricell) manipulation medium, for embryo evaluation [13] under a stereomicroscope (magnification, 20 -40x). The global embryo recovery rate was calculated as the number of structures collected divided by the number of CL present in the ovaries, multiplied by 100 [12].…”