Platelet counting in diagnosis of Rhodococcus equi
Leadon, D.; Farrelly, B.; Fogarty, U.; Buckley, T.
Veterinary Record 123(10): 279
1988
ISSN/ISBN: 0042-4900 PMID: 3188352 Document Number: 318549
A rapid screening test for Rhodococcus equi in foals would indicate need for therapy while awaiting the results of microbial culture or of thoracic radiography. Thrombocytosis is reported as a characteristic of infection and platelet counts have confirmed a diagnosis in 22 foals over a 3-year period. Samples from 10 of these yielded R. equi from blood culture in 6, from transtracheal aspirates in 2 and from bronchioalveolar lavage in 2. Seven of the 10 recovered; R. equi was isolated from pulmonary or mesenteric abscesses of foals that died. The 10 blood samples showed leukocytosis, raised fibrinogen and a mean platelet count of 815+or-328x109/litre; the same technique showed clinically normal foals to have platelet counts of 250+or-100x109/litre. Seven other foals on stud farms having R. equi pneumonia had a mean platelet count of 1341+or-130x109/litre.