Calf-Level Factors Associated with Bovine Neonatal Pancytopenia – A Multi-Country Case-Control Study

Jones, Bryony A.; Sauter-Louis, Carola; Henning, Joerg; Stoll, Alexander; Nielen, Mirjam; Van Schaik, Gerdien; Smolenaars, Anja; Schouten, Matthijs; den Uijl, Ingrid; Fourichon, Christine; Guatteo, Raphael; Madouasse, Aurélien; Nusinovici, Simon; Deprez, Piet; De Vliegher, Sarne; Laureyns, Jozef; Booth, Richard; Cardwell, Jackie M.; Pfeiffer, Dirk U.

All farms that reported suspected cases were visited by a veterinarian, either from the research team or their own veterinarian on behalf of the research team, who conducted a clinical examination. If the calf was less than 29 days of age and had one or more clinical signs of BNP; multiple skin haemorrhages, melena, petechiation of mucous membranes, or sudden death with internal haemorrhage, then it was included in the study as a suspected case. In order to confirm the diagnosis a whole blood sample was collected if the calf was alive, or if the calf was dead then a post mortem examination and bone marrow histopathology were performed. During the same visit, up to four calves without BNP clinical signs and aged 10-28 days were selected from the same farm to be matched controls. Whole blood samples were collected to verify that they did not have abnormal haematology. The veterinarian collected data on the characteristics of suspected case and the unaffected calves by face-to-face questionnaire-based interview (Questionnaire S1).