Neurological disorders, virus persistence and hypomyelination in calves due to intra‐uterine infections with bovine virus diarrhoea virus

Abstract

SUMMARY The results are described of virological and serological research carried out in a Dutch dairy herd during a number of years. The motive was the birth of a number of calves with neurological disorders pointing at an intra-uterine infection with BVD-virus in 1980. Also in the previous and in both the following years a calf was born with similar symptoms. The clinical signs and the course of the affection in these eight calves were described in a previous paper (2). The diagnosis was confirmed through virus isolation from pre-colostral blood of one calf and from autopsy material from four aberrant calves. During the investigation three clinically normal animals with a persistent virus infection were found. The clinically recovered animal of 1979 also proved to be a virus carrier. In addition, in two animals a transient viremia in the presence of specific antibodies was found. The four virus carriers conceived normally. The second pregnancy of the oldest animal also passed normally. Their five calves proved to be BVD-virus carriers as well. One calf, born in 1982, showed nervous disturbances to a serious extent. Of the four other clinically normal animals, one calf was euthanasized because of a serious necrotizing enteritis. The remaining calves stayed healthy and grew up normally. One of the two animals with a transient viremia wasfive months pregnant at that moment. At birth in 1981 her calf showed nervous disorders, but both the virological and the serological examinations of the pre-colostral blood were negative.

Studies on transplacental transmissibility of a Bovine Virus Diarrhoea (BVD) vaccine virus in cattle1

“…Perinatal death or persistent infections, with or without growth retardation, and late onset disease might be the result as was abortion and chronic wasting after female cattle were inoculated with a rota-corona vaccine contaminated by BVD virus ( LOHR et al, 1983). This also reflects the possible outcome of naturally occuring BVD virus infection as described by CORIA and MCCLURKIN (1978), STRAVER et al (1983) and LIES et al (1983). Furthermore, such phenomena have been produced experimentally by using BVD field strains (ROEDER, 1982) and apparently can be a sequel also to immunization with live virus vaccine, as shown in the present report.…”

“…Thereafter, numerous reports have revealed the teratogenic properties of BVD virus. However, after transplacental transfer of BVD virus, long-term viral persistence without teratogenic effects has also been recognized, even in the absence of any clinical symptoms (CORIA and MCCLURKIN, 1978;STRAVER et al, 1983;LIES et al, 1983). Interestingly, no report could be found in the literature of viral persistence in calves after their dams were vaccinated against BVD at an appropriate stage of gestation.…”

Genetic Variability of Bovine Viral Diarrhea Virus and Evidence for a Possible Genetic Bottleneck during Vertical Transmission in Persistently Infected Cattle

“…None of the PI animals examined expressed any CNS related disease signs. However, neurovirulent strains of BVDV have been reported and are associated with ataxia, recumbency, seizures, and CNS hypomyelination in calves [ 40 , 41 ].…”

A Blocking Enzyme‐Linked Immunosorbent Assay (ELISA) for Bovine Virus Diarrhoea Virus Serology

“…Serodiagnosis is most commonly made by a virus neutralization (VN) test (HARKNESS et al, 1978;STECK et al, 1980;STRAVER et al, 1983). Recently two indirect enzyme-linked immunosorbent assays (ELISAs) for BVD virus serology in cattle have been described (CHU et al, 1985;HOWARD et al, 1985).…”