Figure 1From: Distribution and viability of spermatozoa in the canine female genital tract during post-ovulatory oocyte maturationLeft ovary of the same bitch 24 hours before ovulation (a) and at ovulation (b). The preovulatory follicles (a) are characterized by increasing echogenicity of the follicular wall indicating preovulatory luteinisation. Ovulation (b) is indicated by a significant decrease in the amount of fluid in the majority of follicular cavities.Back to article page