Reference values for acute phase proteins in calves and its clinical application

Positive acute phase proteins (APP) are proteins whose concentration in blood increases greatly during the acute phase of inflammation as a systemic response to a local initiation. Although the acute phase reaction cannot help to localise the lesion, changes in APP concentrations can be used to assess severity of the inflammatory disease or to differentiate between acute and chronic inflammation (Horadagoda and others 1999). The importance of APPs as inflammatory markers in veterinary medicine is gradually increasing (Eckersall and Bell 2010), but their clinical use in bovine medicine has been limited partly due to lack of reference values. An increase in APP concentrations during respiratory infections in calves is well established (Ganheim and others 2003, Nikunen and others 2007, Orro and others 2011), and acute-phase response in calves with diarrhoea, umbilical inflammation and other inflammatory diseases has also been examined (Ganheim and others 2007, Tothova and others 2012). This study aimed to establish reference values for fibrinogen (Fb), haptoglobin (Hp) and serum amyloid A (SAA) for young calves. The accuracy of these reference values was also tested in the diagnosis of inflammation severity by using calves with umbilical diseases, as the preliminary umbilical disease diagnosis and the severity of inflammation can be reliably confirmed in surgery. Blood samples from 120 healthy dairy calves were collected from a representative sample of Finnish dairy farms, located in the vicinity of the Production Animal Hospital, University of Helsinki, in southern Finland. The calves were clinically examined for signs of disease and their rectal temperature was also measured. They were included in the study if they showed no signs of illness and their rectal temperature was