Even though the efect of various anticoagulants on hematological and biochemical parameters of human and diferent animals’ blood have been studied in the past but, there is limited information on the efects of hirudin as an anticoagulant substance in dog clinical pathology. In the current study, we evaluated the efcacy of hirudin as an anticoagulant agent compared to EDTA and serum. Twenty adult dogs (ranging from 2 to 6 years old and 25±3 kg) were chosen, and blood samples were taken from the jugular vein and then were added to three test tubes containing anticoagulant substances and one test tube without anticoagulant substance. Hematological and biochemical parameters were analyzed. In the blood containing hirudin, compared to EDTA, the values of RBC, HGB, and PCV were signifcantly decreased, but no signifcant diference was found between the values of other measured parameters. The anticoagulant hirudin increased the values of total protein, β-hydroxybutyric acid, and iron in comparison with serum. In contrast, it had decreasing efects on the values of cholesterol, urea, creatinine, fructosamine, alkaline phosphatase, calcium, inorganic phosphorus, magnesium, sodium, chloride, and potassium (p≤0.05). There were no signifcant changes in the amounts of albumin, total bilirubin, triglyceride, glucose, aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transferase, creatine kinase, lactate dehydrogenase, amylase, and lipase between serum and hirudinized blood samples. There were no signifcant changes in the amounts of other measured parameters between serum and hirudinized blood samples. In the future, hirudin-containing tubes may be used to evaluate hematological and biochemical parameters.

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