Fungi cause sporadic abortions. The abortion occurs from mid to late pregnancy.
Mouldy hay, straw, silage and brewer's grains used as feed or as bedding are the most important sources of infection. Fungi are inhaled and travel via the bloodstream to the placenta. Grey ringworm-like lesions may be seen on the head and shoulders of the foetus, which is not usually decomposed when it is expelled.
Diagnosis is based on isolation of fungi from the foetal stomach, placenta and skin lesions.
The only prophylaxis is strict avoidance of mouldy feed and bedding.