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.

Case recruitment relied on passive reporting by farmers and veterinarians, strengthened by a communication campaign to encourage reporting of cases and provision of free post mortem examination and laboratory testing. The reasons for a farmer or veterinarian not reporting a case might include; being unaware of the invitation to report cases or too busy to report, or having reported cases prior to the study and therefore seeing no benefit in reporting further cases. It is possible that farmers who report disease are more likely to take preventive measures such as vaccination. There is therefore a potential bias in selection of case farms in that the study population might not be representative of all BNP-affected farms in the four countries. But even if these biases were present, they are unlikely to have biased the particular inferences reported here.