Anaemia and mortality in calves infested with the long‐nosed sucking louse ( Linognathus vituli )

Young calves which died on three dairy farms in England and Wales had generalised pallor and heavy infestations of the long‐nosed sucking louse, Linognathus vituli . Surviving calves had packed‐cell volumes, haemoglobin concentrations and red blood cell counts below the reference ranges, consistent with anaemia, and they were also heavily infested with lice. No other causes of anaemia were identified. It is proposed that heavy infestations with L vituli should be considered when investigating the cause of anaemia in calves.