Differences in the association of cough and other clinical signs with ultrasonographic lung consolidation in dairy, veal, and beef calves.

Bovine respiratory disease (BRD) continues to be a leading cause of economic loss, hampered animal welfare, and intensive antimicrobial use in cattle operations worldwide. Reduction of antimicrobial use is hindered because it is still unclear which clinical signs are best monitored to reliably detect pneumonia. Also, these clinical signs may vary according to age and between breeds. The objective of this cross-sectional study was to identify clinical signs associated with ultrasound-confirmed pneumonia (lung consolidation ≥1 cm depth) pre- and postweaning in different production types (dairy, beef, and veal) and breeds. A total of 956 calves (70% Holstein-Friesian dairy and 30% Belgian Blue beef) from 84 herds were clinically examined using 24 parameters, scored using the Wisconsin and California BRD clinical scoring systems and subjected to thoracic ultrasonography. Of the calves, 42.8% and 19.5% had a lung consolidation ≥1 cm and ≥3 cm, respectively. Cough, both spontaneous and induced, was the only and best-performing clinical sign statistically associated with lung consolidation in all production types. Fever (rectal temperature ≥39.4°C) was the second most promising factor, being significant in beef and veal calves but not in dairy calves. Postweaning, none of the clinical signs studied were statistically associated with pneumonia, with the exception of cough in dairy calves. Spontaneous or induced cough as a single clinical sign outperformed any combination of clinical signs, including the Wisconsin and California respiratory disease scoring systems, but sensitivity remained low. This information can be useful to select appropriate clinical signs for continuous monitoring in precision livestock applications, targeted to a given breed and age. As a cross-sectional measurement, diagnostic accuracy of spontaneous cough (accuracy = 65.1%, sensitivity = 37.4%, specificity = 85.7%) is too low to be used as a criterion to select animals with pneumonia for antimicrobial treatment. At the group level, cough monitoring holds potential as an early warning sign, after which lung ultrasonography should follow.

Three cases of alloimmune mediated pancytopenia in calves resembling bovine neonatal pancytopenia.

BACKGROUND: Between 2007 and 2011 several thousands of calves died from bovine neonatal pancytopenia (BNP), a bleeding syndrome triggered by vaccine induced alloantibodies from the dams. Following withdrawal of the involved bovine viral diarrhoea virus (BVDv) vaccine, the incidence of this condition rapidly decreased, with no reported cases in the last 5 years. Here, we report a recent immune-mediated pancytopenia in three calves from two different suckler herds, clinically indistinguishable from BNP. CASE PRESENTATION: Three Belgian Blue suckler calves from two different farms, aged around two weeks, showed multiple bleedings disseminated on the skin and petechiae and ecchymoses on the mucosae. Blood examination confirmed anaemia, leukopenia and thrombocytopenia. BVDv infection was excluded. Despite blood transfusion and cortisone therapy, all three animals died. Necropsy and histology confirmed bone marrow depletion. Binding of IgG from the dams on leukocytes of the calves was demonstrated by flow cytometry. Two calves, originating from the same farm, received colostrum from the same dam. None of the calves were given colostrum replacers or colostrum supplements. No link with the BNP causing BVDv vaccine could be evidenced. However, dams had been vaccinated against bovine herpesvirus 1, parainfluenza-3 virus, bovine respiratory syncytial virus and bluetongue virus serotype 8. CONCLUSIONS: Alloimmune mediated pancytopenia was evidenced in three animals, clinically and pathologically indistinguishable from BNP. Whether this disease is again vaccine mediated remains to be determined.