Ingestion of colostrum from specific cows induces Bovine Neonatal Pancytopenia (BNP) in some calves

Abstract

BackgroundSince 2006, cases of haemorrhagic diathesis in young calves have been observed with a much higher incidence than previously known. The syndrome, now uniformly called Bovine Neonatal Pancytopenia (BNP), is characterized by multiple (external and internal) haemorrhages, thrombocytopenia, leukocytopenia, and bone marrow depletion. Although various infectious and toxicological causes of bleeding disorders in calves have been ruled out, the aetiology of BNP remains unknown. However, field observations have led to the hypothesis that the aetiological principle may be transmitted to calves via colostrum.The objective of the present study was to verify whether ingestion of colostrum from dams of known BNP calves can elicit signs of BNP and typical haematological findings in conveniently selected neonatal calves. Six such calves received one feeding of colostrum (or a mixture of colostrum batches) from dams of known BNP calves. As controls, another six conveniently selected calves from herds which had never had a BNP case received one feeding of colostrum from their own dams. Haematological and clinical parameters were monitored.ResultsOne of the six experimental calves never showed any haematological, clinical or pathological evidence of BNP. In the other five calves, thrombocyte and leukocyte counts dropped within a few hours following ingestion of colostrum. Of those, three calves developed clinical signs of BNP, their post-mortem examination revealed bone marrow depletion. Of the remaining two calves, a pair of mixed twins, marked thrombocytopenia and recurrent leukocytopenia was evident in one, in which only slight changes in the bone marrow were detected, while in the other thrombocyte counts dropped, but rebounded later, and no bone marrow changes were noted. Thrombocyte counts of the experimental calves were statistically significantly lower than those of the control calves at 2 hours post ingestion of colostrum and at every sampling point between 9 hours and 8 days postcolostral. Leucocyte counts of the experimental calves were statistically significantly lower than those of control calves at 2 hours post ingestion of colostrum and 3-7 days postcolostral.ConclusionsBNP can be induced in some calves by ingestion of colostrum from cows that have given birth to BNP calves.

Alloantibodies against MHC Class I: A Novel Mechanism of Neonatal Pancytopenia Linked to Vaccination

“…Their WBC and platelet counts (Fig 1A, 1B) and bone marrow composition progressively returned to normal within 1 mo. The clinical and biological signs of the IgG-injected animals that manifested disease were the same as those reported in natural (1, 2) and colostrum-induced BNP cases (6,7). Our data unequivocally show that IgG collected from BNP dams can induce de novo BNP in unrelated newborn calves.…”

“…BNP has been produced experimentally in some calves through ingestion of particular colostrums (6,7), indicating that immune effectors might be involved. Colostrum has a high concentration of IgG (between 50 and 200 g/l) and provides the calf with its sole source of passive immunity in the first hours of life.…”

Genetic typing of bovine viral diarrhoea virus in cattle on Irish farms

“…Bovine neonatal pancytopenia (BNP), also referred to as haemorrhagic diathesis, bleeding calf syndrome or blood sweating, was first characterized in 2009 following an upsurge in the number of novel and clinically similar cases throughout Europe (Friedrich et al 2011;Bastian et al 2011;Padron et al 2010). This syndrome affects calves <4 weeks of age which typically presents with severe internal and external haemorrhages and fever with pancytopenia and bone marrow depletion also prominent (Friedrich et al 2011;Bastian et al 2011;Padron et al 2010).…”

“…This syndrome affects calves <4 weeks of age which typically presents with severe internal and external haemorrhages and fever with pancytopenia and bone marrow depletion also prominent (Friedrich et al 2011;Bastian et al 2011;Padron et al 2010).…”

“…Investigations identified that BNP is linked to vaccine-induced, maternal antibodies (Bridger et al 2010;Friedrich et al 2011). Research suggested that bioprocess impurities in PregSure® BVD, a strongly adjuvanted, inactivated vaccine against BVD contributed to the development of BNP and as a result, this vaccine is no longer licenced for use (Bastian et al 2011).…”