This report describes normal histology of tissues from immature female dogs and sequential microscopic changes that occur during different stages of the estrous cycle in ovary, uterus, vagina and mammary glands.
Estrous Cycle‐Dependent Histology and Review of Sex Steroid Receptor Expression in Dog Reproductive Tissues and Mammary Gland and Associated Hormone Levels
Birth Defects Research Part B: Developmental and Reproductive Toxicology, 2007