New hemorrhagic symptoms have been striking calves aged less than thirty days old, particularly in the last five years. Since last December this disease, the causes of which we still don’t know, has gained a name: bovine neonatal pancytopenia. These haemorrhages, which can be cerebral, bring about the death of young bovines, sometime within 48 hours. In Belgium, these hemorrhagic symptoms, which affect around one calf in ten thousand, has attracted the complete attention of a young researcher, Léonard Theron.

Breeders and veterinary doctors know it very well: hemorrhagic syndromes striking bovines and, more specifically calves, are not new phenomena. For decades now, in effect, the causes of these syndromes have been identified and are today well known. In the 1970s, for example, furazolidone, a substance present in milk powder, was identified as causing a severe bone marrow failure, the source of a peripheral pancytopenia. Over the course of the 1990s, it was the turn of a pestivirus, Bovine Viral Diarrhea Virus (BVDV), to cause sporadic haemorrhages in Europe and epidemic haemorrhages in North America.

Nevertheless since the beginning of the 2000s, and more particularly since five years ago, dozens of cases of hemorrhagic syndromes have been described for new born calves, this time with an important difference: to this day no cause has been identified. It was German farmers and vets who were the first to sound the alarm bell, as over 200 cases have been detected in close to 170 farms. In Germany the situation was rapidly judged worrying as the number of cases of hemorrhagic diseases detected since 2005 is as large as for the last thirty years! This also explains the role taken by the German scientific community in this issue, and notably by the University of Munich’s Veterinary Faculty and Professor Klee.

Other cases, more limited in number for the present, have also been recorded in France and the United Kingdom, whilst in Belgium the University of Ghent’s veterinary faculty has logged around a sixty cases in forty farms. ‘But,’ warns Léonard Theron, a researcher in the University of Liège’s Faculty of Veterinary Medicine’s production animals clinical department, ‘two elements have us believe that these cases could be more numerous: on the one hand the crisis, which incites farmers only to make contact with vets or research centres after the death of several beasts to avoid an inflation of expenditure, and on the other the reduction in the number of vets in certain regions, notably French, which weakens their capacity to detect certain emergent diseases.’ To this we would add that because of the low number of cases and the rapidity of mortality, few farmers have taken the trouble to have their calves analysed. In the Summer of 2009 Léonard Theron received an acute case at the Faculty, a calf aged 25 days, on which he carried out a series of examinations and sample taking (see below): three other bovines had died at this farm following haemorrhages before the farmer decided to have his fourth sick calf examined.