Page 1037 - Veterinary Immunology, 10th Edition

The disease is triggered by administration of a specific vaccine
VetBooks.ir against bovine viral diarrhea virus (BVDV) (Fig. 31.2). This vaccine

contained inactivated BVDV grown in a bovine kidney cell line. A
potent, oil-in-water adjuvant containing Quil-A is added (Chapter

24). Immunization with the vaccine induces high levels of
antibodies against the class I MHC antigens expressed by the
kidney cells.When transferred to calves via colostrum, these
antibodies bind to leukocytes and bone marrow stem cells, kill

them, and so induce pancytopenia and bone marrow destruction.
Only a few of the calves born from mothers that received this
specific vaccine develop clinical disease. The reasons for this are
unknown but most likely depend upon their MHC haplotype.

Antibody levels remain high in cows for many years and may be
boosted by each pregnancy. As a result, BNP cases may occur many
years after the offending vaccine was removed from the market.

FIG. 31.2 The pathogenesis of bovine neonatal pancytopenia.

Sheep

The blood groups of sheep resemble those of cattle. Six blood group
systems (EAA, EAB, EAC, EAD, EAM, and EAR) are currently

recognized. The ovine equivalent of bovine EAB is also termed EAB
and, like the bovine system, is complex, containing at least 52
different alleles. Sheep also possess an ovine equivalent of the
bovine EAJ system, called the EAR system. Two soluble antigens

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