Evaluation of serum acute phase protein concentrations in various diseases in horses

Glikoproteins that blood concentrations rapidly changes just after tissue injury is so called acute phase proteins (APP), and the response is called acute phase response (APR). According to their nature; APR is non-spesific and may start after the infections, immunologic disease, neoplastic conditions, traumatic, parasitic or other causes. Serum amyloid A (SAA) is the most important diagnostic and prognostic APP in horses. Haptoglobin (Hp), fibrinojen (Fb), α1-asit glikoprotein (AGP) and C-reactive protein (CRP) are the mediatly important APPs in horse. Recent studies in horse on APP revealed high increases of APP concentrations in viral and bacterial infections, surgical attempts, colics and induced arthritis. In this study, it was aimed to determine APP levels and its clinical use in different diseases, differentiation of acute, subacute and chronic disease progress and local / systemic conditions. The animal material of this study is 10 healthy and 81 horses (44 female and 47 male) with different diseases in various breed and ages between 6 months to 23 years admitted to the clinics of Medika-Vet Animal Hospital. After collecting blood samples with the usual techniques, WBC counts, SAA, Hp and Fb levels were measured. Serum amyloid A and Fb concentrations were statistically higher in horses with various diseases (respectively; p<0,001 and p<0,05). Haptoglobin concentrations were also higher in diseased horses however, a statistical significance could not be detected. White blood cell counts and Fb concentrations were significantly higher in acute condition comparing with the subacute. No difrence were detected in SAA and Hp between subacute and acute terms. Fibrinogen has lowest levels in acute cases. In local or systemic comparison of the diseases, we could not find any statistical difference in APP concentrations. In this study with the comparison of different diseases, localisation and disease progress of APP levels, it was concluded that: • Serum amyloid A and plasma Fb concentrations were higher in various diseases comparing to the healthy horses. • APP's can be used in determination of the term of the disease, serum Hp and plasma Fb concentrations in horses is a valuable diagnostic tool in detection of the chronic situation. • Increased concentrations of SAA and Fb can be a diagnostic tool in determination of inflammation in horses; however, it can not be used to differentiate the site (local / sistemic) of the inflammation. Keywords: Horse, serum amyloid A, haptoglobin, fibrinogen