Mammary Gland in Other Animals Mammary glands can be inguinal, thoracic or abdominal. Goat, Cow, Sheep and Horse have inguinal glands Pigs, Dogs and Cats have multiple glands from the thoracic to the inguinal region and are all litter bearing. Mammogenesis Mammogenesis refers to the growth and development of the mammary gland. During embryologic development, a milk or mammary band appears on each side of the abdominal wall. Mammary glands develop along this band according to the species.
Most domestic animals have glands only in the inguinal region.
Development in Cattle At birth, the female calf has a teat and gland cisterns that are formed. Mammary ducts are confined at this stage to the region of the gland cistern. The growth of the mammary gland is similar to the rest of the body growth until puberty. At this point the growth of the glandular tissue exceeds the general rate of body growth. Hormones involved in mammary development are estrogen and progesterone at puberty and placental lactogen during pregnancy in combination with estradiol and progesterone.