Bleeding calf syndrome

Bleeding calf syndrome (Bovine neonatal pancytopenia) results in unexplained bleeding or haemorrhaging from the skin, nares, mouth, rectum and injection sites and ear tags and with a raised temperature in some cases. 

Clinical signs

There have been different clinical manifestations seen, ranging from calves being found dead to unexpected excessive bleeding with secondary infection and malaise and on post mortem areas of bleeding or haemorrhage are seen throughout the carcase. The bone marrow also shows damage (aplasia) indicating that there is a problem with producing factors involved in blood clotting.

Most calves first showed clinical signs between 1-2 weeks of age and the majority died within a few days of first showing the clinical signs.

Numbers affected per herd vary considerably from the one calf to 3 to 5% of calves but generally numbers are very low and the indication is that this is unlikely to suddenly increase. Mortality would appear to be very high with few reports of calves recovering. The disease has been reported in both closed and open herds.


As yet the causal agent has not been elucidated but it is postulated that it may be an auto-immune mediated disease but poisoning, genetic abnormalities and drug reactions are all being considered. There are no known reports of any associated human illness and there appears to be absolutely no risk to human health and affected animals do not appear to be a human health risk.

The advice is to be vigilant and investigate any unexplained cases of bleeding or sudden death in young calves.

Further investigations are planned. Both the VLA and SAC are carrying out detailed investigations and a questionnaire has been developed to look for common features between cases.