Mycotic Abortion in the Bovine Fact File
Mycotic abortions in cattle tend to occur between 6-8 months gestation and placenta’s are usually firmly retained. Gross lesions are usually confined to the placenta and fetus. Endometrial lesions are usually less severe than placental lesions but secondary infections may follow retention of the placenta. In ruminants it is thought that fungi originate from the maternal respiratory tract or from ruminal lesions and spread hematogenously to the placentomes with further spread to the intercotyledonary areas of the placenta.
Mycotic abortion accounts for 6-7% of bovine abortions. As endometrial lesions, in general, are less severe than in the placenta, long term fertility of these animals is not affected and the majority of cows recover after abortion and calve again. However, in cases of severe endometrial destruction breeding future of the cow maybe adversely affected.
Fetal cutaneous lesions have a site predeliction for periorbital areas, shoulders, back and flanks. Occasionally the fetus may aspirate organisms from the amniotic fluid initiating a bronchopneumonia, but typically there is no systemic spread from the skin sites. Swallowing of amniotic fluid by the fetus on the other hand is a common occurrence and hence fungal culture from the abomasal fluid of the fetus is a useful and effective diagnostic tool.