Failure of milk let down in the mare
Agalactia is the scientific word to describe the failure to secrete milk (or colostrum) from the mammary gland. Agalactia is apparent immediately at parturition when the mare fails to produce colostrum even though the foal has latched onto the teat and is sucking well. The condition is a serious threat because the newborn foal will be left immunocompromised, due to failure of passive transfer, and severe dehydration in neonates quickly results in secondary problems such as renal dysfunction. Luckily, agalactia is relatively rare. However, mares that become ill after parturition (that initially develop normal milk let down) may stop producing milk due to the severe illness (known as hypogalactia) and this creates similar complications to those of agalactic mares.