Statistics from Altmetric.com
ALL bovine viral diarrhoea virus (BVDV) strains can appear both as the cytopathic and the non-cytopathic biotype. Although both can infect the fetus, only non-cytopathic BVDV is able to cause persistent infection (Brownlie and others 1989). Furthermore, all offspring of persistently infected (PI) dams are PI (Liebler-Tenorio 2005). In the field, cytopathic BVDV strains are typically isolated from cases of mucosal disease (MD) or associated with the use of modified live vaccine (Ridpath 2005). In cases of MD, both cytopathic and non-cytopathic BVDV are present in the same animal. The incubation period takes two to three weeks in early-onset MD, but can be extended by months or years in late-onset MD (Brownlie and Clarke 1993). MD usually affects animals aged six to 18 months, although occasionally it has been reported in calves a few weeks old (Brownlie 2004). This short communication reports the detection of cytopathic BVDV in a 10-day-old calf during an outbreak of haemorrhagic diarrhoea.
Between 2004 and 2007, sporadic cases of non-fatal haemorrhagic diarrhoea in neonatal calves occurred in a herd consisting of 60 Holstein-Friesian and 150 Belgian blue breeding cattle and their offspring. In 2007, the number of affected newborn calves increased, and two calves died at the age of five and six months from neurological disease. Because these animals were BVDV antigen ELISA-positive at postmortem examination, vaccination with two inactivated BVDV vaccines was begun. A farm-wide screening programme for PI …