Spatial distribution and incidence of bovine neonatal pancytopenia in Bavaria, Germany.

BACKGROUND: Bovine neonatal pancytopenia (BNP) is a haemorrhagic disease of neonatal calves. BNP was first described in Germany in 2009, later on also in other European countries, and in New Zealand in 2011. The disease is characterised by spontaneous bleeding, pancytopaenia in the bone marrow, and a high case fatality ratio. The causal role of a specific bovine viral diarrhoea virus (BVDV) vaccine (PregSure®BVD, then Pfizer Animal Health, now Zoetis, Berlin, Germany) has been established over the last years, causing the production of alloantibodies in some vaccinated cattle, which in the case of pregnant cattle, are transferred to the newborn calf via the colostrum. However, striking regional differences in the incidence of the disease were observed within Germany and other countries, but as the disease was not notifiable, no representative data on the spatial distribution are available. In this study, we address the spatial distribution and incidence of BNP using the results of two representative surveys amongst cattle practitioners in Bavaria, Germany. The surveys, asking about the occurrence of BNP, were conducted in 2009 and 2010. Answers were analysed spatially by testing for clusters using space-time models. Practitioners were also asked how many cows they serve in their practice and this number was used to estimate the incidence of BNP. Furthermore, in the survey of 2010, practitioners were also asked about usage of vaccine against BVDV. RESULTS: From the results of the surveys, three clusters were identified in Bavaria. These clusters also coincided with the usage of the specific BVDV vaccine as indicated by the veterinary practices. Furthermore, the representative surveys allow the estimation of the incidence of BNP to be in the order of 4 cases per 10,000 calves at risk. CONCLUSIONS: The study is the only representative survey conducted on BNP. Despite the fact that BNP is a non-infectious disease, regional clusters were identified.

Heterotopy ("Error loci") of the spiral loop of the ascending colon in cattle.

The term heterotopy of the spiral colon encompasses a dysmorphological condition in which the spiral loops of the ascending colon (SLACs) do not form an orderly spiraling mass adjacent to the left side of the mesojejunum. As a consequence, the spiral loops are spread over a larger surface, making them more or less movable. It has been hypothesized that the abnormal position of the spiral loops of the ascending colon might constitute a predisposing factor for an intestinal obstruction or an ileus condition. The objective of the present study was to evaluate the anatomy of the spiral loops of the ascending colon in a population of healthy calves and to determine the prevalence of dysmorphism. The investigation was carried out on 1113 slaughtered veal calves. In 472 out of the 1113 calves, the spiral loops showed conformational aspects different from what has so far been described as normal in reference textbooks. In 91 calves the condition was definitely considered a pathological deviation from normality: in fact, the spiral colon had lost its typical spiral shape with random spacing between the loops, and it was nearly or completely detached from the mesojejunum. The lack of a broad attachment of the spiral loops of the ascending colon to the mesentery could provoke an alteration of the intestinal centre of gravity, enhancing the already asymmetrical distribution of weight between the jejunum and the descending colon.

Case control study to investigate risk factors for bovine neonatal pancytopenia (BNP) in young calves in southern Germany.

A case control study on farm level was conducted at the Clinic for Ruminants, LMU Munich, to identify possible risk factors associated with the observed increase in numbers of calves showing clinical signs of Bovine Neonatal Pancytopenia (BNP) since 2006 in southern Germany. Interviews were conducted between August 2008 and June 2010. The characteristics of 56 dairy farms with at least one confirmed case of BNP (thrombocytopenia and leukocytopenia and/or typical findings in post-mortem examination and bone marrow histology) were compared with those of two sets of 50 control dairy farms each, with no history of BNP. The first set of 50 control farms was selected randomly from veterinary practices which had never observed a BNP case on the farms they serviced. The second set of 50 control farms was matched by the veterinary practices which had provided case farms. Two separate analyses were conducted: (1) case farms (n=56) vs. randomly selected control farms (n=50) and (2) case farms (n=56) vs. a matched set of control farms (n=50). All variables with p<0.2 in the univariable analysis were included in stepwise logistic regression models. In the first analysis, only the use of PregSure(®) BVD vaccine was positively associated with BNP with an odds ratio of 1292 (95% CI: 114-14707). In the second analysis, conditional logistic regression models did not converge, therefore non-conditional logistic regression models were conducted. In the non-conditional analysis five variables remained in the model, three of which were negatively associated with BNP: the use of vitamin E and selenium, the frequent use of mastitis tubes, and the use of stem growth regulators in grain production. The use of prophylactic measures (such as control of parasites or vaccination of calves against respiratory disease) was positively associated with BNP with an odds ratio of 14.3 as well as the use of PregSure(®) BVD vaccine with an odds ratio of 426 (95% CI: 20-9095).

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

BACKGROUND: Since 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. RESULTS: One 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. CONCLUSIONS: BNP can be induced in some calves by ingestion of colostrum from cows that have given birth to BNP calves.