Clinical haematology and biochemistry profiles of cattle naturally infected with <i>Theileria orientalis</i> Ikeda type in New Zealand
Creators: name: KE Lawrence
name: SF Forsyth
name: BL Vaatstra
name: AMJ McFadden
name: DJ Pulford
name: K Govindaraju
name: WE Pomroy
Publisher: name: Taylor & Francis
Year: 2017
Subjects: subject: Biochemistry
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: FOS: Biological sciences
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: FOS: Earth and related environmental sciences
subject: Sociology
subject: FOS: Sociology
subject: FOS: Sociology
subject: Immunology
subject: FOS: Clinical medicine
subject: FOS: Clinical medicine
subject: 69999 Biological Sciences not elsewhere classified
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: FOS: Health sciences
subject: Computational Biology

description: AIMS: To present the haematology and biochemistry profiles for cattle in New Zealand naturally infected with <i>Theileria orientalis</i> Ikeda type and investigate if the results differed between adult dairy cattle and calves aged &lt;6 months. METHODS: Haematology and biochemistry results were obtained from blood samples from cattle which tested positive for <i>T. orientalis</i> Ikeda type by PCR, that were submitted to veterinary laboratories in New Zealand between October 2012 and November 2014. Data sets for haematology and biochemistry results were prepared for adult dairy cattle (n=62 and 28, respectively) and calves aged &lt;6 months (n=62 and 28, respectively), which were matched on the basis of individual haematocrit (HCT). Results were compared between age groups when categorised by HCT. Selected variables were plotted against individual HCT, and locally weighted scatterplot smoothing (Loess) curves were fitted to the data for adult dairy cattle and calves &lt;6 months old. RESULTS: When categorised by HCT, the proportion of samples with HCT &lt;0.15 L/L (severe anaemia) was greater for adult dairy cattle than for beef or dairy calves, for both haematology (p&lt;0.002) and biochemistry (p&lt;0.001) submissions. There were differences (p&lt;0.05) between adult dairy cattle and calves aged &lt;6 months in the relationships between HCT and red blood cell counts, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentrations, lymphocyte and eosinophil counts, and activities of glutamate dehydrogenase and aspartate aminotransferase. In both age groups anisocytosis was frequently recorded. The proportion of blood smears showing mild and moderate macrocytosis was greater in adults than calves (p=0.01), and mild and moderate poikilocytosis was greater in calves than adults (p=0.005). CONCLUSIONS AND CLINICAL RELEVANCE: The haematology and biochemistry changes observed in cattle infected with <i>T. orientalis</i> Ikeda type were consistent with extravascular haemolytic anaemia. Adult dairy cattle were more likely to be severely anaemic than calves. There were differences in haematology and biochemistry profiles between adult dairy cattle and calves, but most of these differences likely had a physiological rather than pathological basis. Overall, the haematological changes in calves aged &lt;6 months appeared less severe than in adult dairy cattle.