Occurrence of congenital cerebral theileriosis in a newborn twin Holstein calves in Iran: Case report.

An 8-day-old newborn female twin Holstein calves with a history of weakness, anorexia, emaciation and convulsion were presented to Tabriz University Veterinary Teaching Hospital. On admission, the calves were febrile and recumbent. Physical examination revealed many ticks from the external body surface of the animals, right and left prescapular lymphadenopathy, severe opisthotonos, nystagmus, pedaling, blindness, hyperpnea and hypersthenia. Buccal and vaginal mucous were pale and no other physical abnormalities were diagnosed. Fecal flotation, complete blood count, bone marrow aspiration, cerebrospinal fluid (CSF) analysis, necropsy and histopathological examination were performed. Fecal flotation showed no helminth eggs or coccidial oocysts. On blood smears obtained from the earlap, >70 percent of erythrocytes were infected with piroplasms organisms and schizonts were obvious in smears of lymphocytes lymph node. Blood count revealed a lymphopenia, poikilocytosis, anisocytosis and non-regenerative anemia (packed cell volume; mean, 16%). Histopathological examination revealed Arthus reaction through the walls of cerebral blood vessels, which resulted in local necrosis of the brain. Analysis of CSF showed no abnormality in appearance or biochemical and cell counts. Although the calves were treated with a single intramuscular injection of buparvaquone and oxytetracycline once daily they did not respond to the treatment and died. In conclusion, the present cases showed a rare cerebral form of theileriosis by vertical transmission that confirmed by the presence of piroplasms on blood films and multinuclear schizonts on lymph node aspiration smears, gross and histopathological examinations and unsuccessful treatment in a newborn twin Holstein calves.