Calf-level factors associated with bovine neonatal pancytopenia--a multi-country case-control study

PLoS One. 2013 Dec 2;8(12):e80619. doi: 10.1371/journal.pone.0080619. eCollection 2013.

Abstract

Bovine neonatal pancytopenia (BNP), a high fatality condition causing haemorrhages in calves aged less than 4 weeks, was first reported in 2007 in Germany and subsequently observed at low incidence in other European countries and New Zealand. A multi-country matched case-control study was conducted in 2011 to identify calf-level risk factors for BNP. 405 BNP cases were recruited from 330 farms in Belgium, France, Germany and the Netherlands by laboratory confirmation of farmer-reported cases. Up to four calves of similar age from the same farm were selected as controls (1154 calves). Risk factor data were collected by questionnaire. Multivariable modelling using conditional logistic regression indicated that PregSure®BVD (PregSure, Pfizer Animal Health) vaccination of the dam was strongly associated with BNP cases (adjusted matched Odds Ratio - amOR 17.8 first lactation dams; 95% confidence interval - ci 2.4, 134.4; p = 0.005), and second or more lactation PregSure-vaccinated dams were more likely to have a case than first lactation vaccinated dams (amOR 2.2 second lactation; ci 1.1, 4.3; p = 0.024; amOR 5.3 third or more lactation; ci 2.9, 9.8; p = <0.001). Feeding colostrum from other cows was strongly associated with BNP if the dam was not PregSure-vaccinated (amOR 30.5; ci 2.1, 440.5; p = 0.012), but the effect was less if the dam was PregSure-vaccinated (amOR 2.1; ci 1.1, 4.0; p = 0.024). Feeding exclusively dam's milk was a higher risk than other types of milk (amOR 3.4; ci 1.6, 7.5; p = 0.002). The population attributable fractions were 0.84 (ci 0.68, 0.92) for PregSure vaccination, 0.13 (ci 0.06, 0.19) for feeding other cows' colostrum, and 0.15 (ci 0.08, 0.22) for feeding dam's milk. No other calf-level factors were identified, suggesting that there are other important factors that are outside the scope of this study, such as genetics, which explain why BNP develops in some PregSure-colostrum-exposed calves but not in others.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bovine Virus Diarrhea-Mucosal Disease* / epidemiology
  • Bovine Virus Diarrhea-Mucosal Disease* / prevention & control
  • Cattle
  • Diarrhea Virus 1, Bovine Viral
  • Europe / epidemiology
  • Hemorrhage* / epidemiology
  • Hemorrhage* / prevention & control
  • Hemorrhage* / veterinary
  • Hemorrhage* / virology
  • Models, Biological*
  • Pancytopenia* / epidemiology
  • Pancytopenia* / prevention & control
  • Pancytopenia* / veterinary
  • Pancytopenia* / virology
  • Vaccination / methods
  • Viral Vaccines / pharmacology

Substances

  • Viral Vaccines

Grants and funding

This study was funded by Pfizer Animal Health (www.Zoetis.com). The grant number was 1329. The following Pfizer personnel were observers during the study: Jeremy Salt, Michael Pearce, Tony Simon and Marie-Odile Hendrickx. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript, except attendance at project coordination meetings as observers, and commenting on the draft manuscript.