Clinical trypanosomosis due toTrypanosoma theileri in a cow in Iran

Trop. Anita. Hlth Prod. (1995) 27, 93-94

Clinical Note CLINICAL TRYPANOSOMOSIS DUE TO TRYPANOSOMA THEILF~RI IN A COW IN IRAN H. A. SEIFI Department of ClinicalSciences, Facultyof Veterinary Medicine, Universityof Tehran, PO Box 14155-6453 Tehran, Iran Trypanosoma theileri is a cosmopolitan blood parasite of cattle transmitted by tabanid flies, although it is rarely observed in direct blood smears (Levine et al., 1956; Levine, 1985). Although the parasite is mostly considered harmless, it has been found to be pathogenic in the presence of other diseases including anaplasmosis, theileriosis and also after immunisation against rinderpest (Levine et al., 1956; Hoare, 1972). This communication reports a clinical case of bovine trypanosomosis due to T. theileri in Iran. In July 1990 a 6 year old native cow with loss of appetite and decreased milk yield was admitted to the Veterinary Clinic, Urmia University. The animal also had a history of epistaxis and blood-tinged diarrhoea 6 days prior to admission. Three days before admission, the cow was examined by a private veterinarian and sulphadimidine was administered. On clinical examination, the animal was pyrexic (39-6°C) and had slight

F~o. 1. Giemsastainedblood smearshowing3 parasites. 93

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SEIFI

tachypnoea (32/min) and tachycardia (112/min). Heart sounds were strong and could be auscultated over left and fight paralumbar fossa. The visible mucous membranes were anaemic whereas those in the vulva and vagina had petechial hemorrhages. Prescapular and prefemoral lymph nodes were enlarged. Haematological analysis revealed a very low packed cell volume (9%) and a leukocytosis (17.5 x 10"/litre) due to neutrophilia (6.1 x 109/titre) and a marked tymphocytosis (10-3 x t09/litre). Microscopic examination of Giemsa-stained blood smears showed a large number of trypanosomes (Fig. 1). However, the animal was negative for other blood protozoal and anaplasma infections. Aspirated material from lymph nodes was also negative for theileria organisms, but some tryponosomes could be seen. The parasite was long (45 4- 5 #m) and identified as T. theileri by Professor Edrissian of Tehran University of Medical Sciences. Before any treatment was possible the cow died because of hypoxia due to severe anaemia. The clinical signs of anaemia, pyrexia, tachypnoea, tachycardia, enlarged lymph nodes and blood-stained diarrhoea could be caused by a number of diseases. In this case, the findings ruled out other haemoparasitic diseases such as babesiosis, theileriosis, anaplasmosis and other trypanosomes. No attempt was made, however, to investigate other possible aetiological agents such as bacterial or viral infections. The clinical signs of pyrexia, anaemia and lymphocytosis of a calf with T. theileri infection (Doherty et al., 1993) are similar to findings reported here. A correlation between Iymphocytosis and T. theileri infection in cattle has also been observed by Cross et al. (1971). These reports together with the findings recorded here strongly indicate that 7". theileri should be considered as an occasional pathogen of cattle. ACKNOWLEDGMENTS

The author thanks Professor Gh. Edrissian from Tehran University o f Medical Sdences and Dr S. Rahbari, associate professor of the Faculty of Veterinary Medidne, University of Tehran. Accepted for publication May 1994 REFERENCES Caoss, IL F., SMrm, C. IC & R ~ , D. R. (197I). Observations on Trypanosoma theileri infection in cattle. CanadianJournal of Comparative Medicine, 35, 12-17. DOHERTY,M. L., WINDLE,H., Vooam~s, H. P., L~a~IN, H., C~sEY, M., CLERY,D. & MURRAY,M. (1993). Clinical disease associated with Trypanosoma thetleri infection in a calf in Ireland. Veterinary Recor~ 132, 653-656. HOARE,C. A. (1972). The Trypanosomes of Mammals. Blackwell Scientific Publication, Oxford, pp 125141. LEV1N~,N. D. (1985). Veterinary Protozoology. The Iowa State University Press, Ames, pp 46. Lev~a, N. D., WATCH, A. M., KA~cma,S. & HAgo~eJtoog, H. J. (1956). A case of bovine trypanosomiasis due to Trypanosoma theUeriin Illinois. Journalof Parasitology,42, 553.