Pregnant Uterus - Response to Disease

General responses to disease (+/-infection) during pregnancy

1. Death of the foetus and resorption: early embryonic death and return to oestrus.
2. Maceration and emphysema: uterine infection early in pregnancy results in maceration and expulsion. Endometritis or pyometra may also be present. Emphysema occurs when dead foetal tissue invaded by putrefactive bacteria (Clostridia).
3. Mummification: no bacterial infection, fluids resorbed, foetus retained as black leathery mass, takes 6-8 months;
   • Parvovirus, enterovirus (SMEDI) in sows
   • BVD in cows
   • Twinning, premature placental separation, torsion of umbilical cord (slowly developing ischaemia) in mares. Non-specific.
4. Abortion: before foetus viable. Secondary to foetal death due to damage to uterus, placenta or foetus.
5. Stillbirth: after foetus potentially viable.
6. Live birth: normal or abnormal neonate.
7. Congenital malformation of the foetus;
   • genetic factors i.e. inherited or acquired.
   • environmental factors i.e. physical, chemical, nutritional, hormonal, infectious agents.
8. Retained foetal membranes: metritis/endometritis.

Information by permission of Professor RW Else