Abstract :
Bovine virus diarrhea virus (BVDV) has recently been identified as an important infectious
disease of new world camelids (NWC) particularly alpacas. Both sub-genotypes 1a, 1b and
genotype 2 have been isolated. However, non-cytopathic BVDV 1b is reported to be primarily
implicated in cases of BVDV in NWC’s. Although suspected a BVDV strain unique
to camelids have not been isolated. The most important source of BVDV is the immunotolerant
persistently infected cria. Natural transient infection of BVDV in NWCs is reported
to go almost undetected except for vague signs of illness, including lethargy and anorexia.
Diarrhea does not appear to be a constant finding. Embryonal/fetal disease in NWC’s
includes early pregnancy loss, abortion and premature birth or the birth of persistently
infected crias. Persistently infected disease can occur in both acute and chronic forms. In
NWCs the chronic form of the condition is most commonly reported. Signs include chronic
ill-thrift, poor weight gain or being underweight, intermittent illness, chronic diarrhea,
joint swelling and episodes of nasal discharge and pneumonia despite antibiotic treatment.
The mortality rate in NWCs appears to be close to 100%. Seroprevalence of BVDV in NWCs
ranged from 2.05% to 11.11% however the possibility that the correct (homologous) BVDV
strain is not being used in serological assays need to be considered. The importance of cattle
as a source of BVDV for camelids is unclear although there is consensus of a spill-over from
cattle to NWC’s. Assays available for BVDV in cattle appear to work for camelids. An antigen
ELISA which is the usual method for detectingBVDin cattle has not been validated in NWC’s.
