Anaplasmosis and theileriosis are important diseases with great economic impact that affect the cattle industry worldwide. In this study, we describe the first molecularly confirmed clinical cases of anaplasmosis caused by Anaplasma marginale and of a concurrent infection with A. bovis and Theileria orientalis in Croatian cattle. Clinical signs of A. marginale-infected cows included fever, lethargy, dark urine, as well as icteric and reddish mucous membranes. Postmortem examination revealed icterus, urinary bladder filled with dark urine and splenomegaly. A marginale was observed within erythrocytes on Giemsa-stained spleen imprints. Three affected cows were successfully treated with oxytetracycline, after which no new deaths occurred in the herd. Three cows in a different herd died suddenly and were found to be concurrently infected with A. bovis and T. orientalis. Postmortem examination revealed generalized icterus and urinary bladder filled with dark urine. These cases of A. marginale, A. bovis and T. orientalis infection show that bovine anaplasmosis and theileriosis are present within Croatian cattle and should be included in differential diagnostic protocols.

METHODS: On 7 September 2012 the Ministry for Primary Industries was notified of a dairy cow with regenerative anaemia (haematocrit (HCT) 0.08 L/L) in a herd of 465 Jersey-Friesian cross cows (index case herd) in the Northland region of New Zealand. Organisms consistent with Theileria spp. were present in red blood cells on a blood smear. No other causes of anaemia were detected following examination of affected cows. Blood samples collected from 29 randomly selected cows on 26 September 2012 showed that 24 (83%) were anaemic (HCT≤0.24 L/L) and therefore fitted the case definition for bovine anaemia associated with Theileria orientalis infection.
RESULTS: Using a T. orientalis type-specific PCR assay that targeted the single subunit rRNA gene, all of six animals tested were positive for T. orientalis type Ikeda. Blood samples collected from clinically affected cattle in 11 subsequent outbreaks from throughout the North Island showed that T. orientalis Ikeda type was a common finding, but mixed infections with Chitose type were also identified. In addition, using a PCR assay that targeted the major piroplasm surface gene, T. orientalis type 5 was detected in one cow from the Waikato region.
METHODS: The presence of T. orientalis type Ikeda, as well as type 5, was confirmed in cattle from outbreaks of bovine anaemia in herds throughout the North Island of New Zealand.
CONCLUSIONS: Two new types of T. orientalis were identified in this investigation, that were associated with a sudden rise in cases of bovine anaemia. The body of evidence showed that the Ikeda type was implicated as the cause of disease observed in this epidemic.