Bovine Neonatal Pancytopenia - correlation between clinical symptoms, hematological parameters and lifespan.

OBJECTIVE: To compare the hematological parameters and clinical symptoms between Bovine Neonatal Pancytopenia (BNP) diseased calves dying before and after 14 days of life.

MATERIAL AND METHODS: Clinical observations included 47 calves from dams which underwent a 3-year vaccination program with the inactivated PregSure® BVD vaccine. In 25 of these 47 BNP affected calves blood examinations were performed and in 22 dead calves diagnosis was mainly based on post-mortem findings.

RESULTS: Cutaneous bleeding was the predominant clinical manifestation in 32 from 47 calves (68.1%). Seven from 47 calves (14.9%) developed cutaneous bleeding as the only symptom and 17 from 47 calves (36.2%) demonstrated these alterations in combination with hemorrhagic lesions of the oral mucosa. In 66.0% (31/47) of calves petechiae of the oral mucosa were seen and petechiation without any other BNP related symptoms occurred in eight from 47 calves (17.0%). The hematological analysis revealed thrombocytopenia in all 25 cases (n = 23: PLT < 60 x 109 /l, n = 2: PLT 139-164 x 109 /l). Nineteen from 25 calves (76.0%) developed thrombocytopenia and leukocytopenia (WBC < 3.5 x 109 /l). In nine of them a decrease of erythrocyte count (RBC < 4.5 x 109 /l), hemoglobin concentration (Hb < 8 g/dl) and packed cell volume (PCV < 24%) was measured. Three BNP affected calves without clinical symptoms were identified by hematological examination. The average life time of BNP affected calves was 14.7 ± 6.2 days. Clinical findings, especially multifocal cutaneous hemorrhages were more frequently recognized in calves living longer than 14 days.

CONCLUSION AND CLINICAL RELEVANCE: At the time of falling ill with BNP, older calves displayed more numerous symptoms, especially bleeding in the skin. Thrombocytopenia and erythropenia occur as well as a decreased hemoglobin concentration and a low PCV. The time between outbreak of symptoms and death of calves which fell ill later, did not differ from the survival time of BNP calves, which displayed symptoms at a younger age. A decrease of thrombocytes was the cardinal laboratory finding.