Comparison of Biochemical Values of Paired Serum and Plasma Samples from American Flamingos (Phoenicopterus ruber), Indian Runner Ducks (Anas platyrhynchos), and Hyacinth Macaws (Anodorhynchus hyacinthinus)

Single blood samples from 8 clinically normal adult Indian runner ducks (Anas platyrhynchos), 8 clinically normal American flamingos (Phoenicopterus ruber), and 3 blood samples from each of 4 clinically normal hyacinth macaws (Anodorhynchus hyacinthinus) were collected to compare the biochemical values of paired plasma samples from heparinized blood with those of serum samples from clotted blood. Small but significant differences (P < 0.05) were found between paired serum and plasma samples for some biochemistries. In flamingos, potassium (P = 0.001), albumin (P = 0.03), and alanine aminotransferase (P = 0.02) were significantly higher in serum compared with plasma, whereas total protein (P = 0.04) and globulin (P = 0.01) were significantly lower in serum compared with plasma. In Indian runner ducks, potassium (P = 0.0002), chloride (P = 0.02), and alanine aminotransferase (P = 0.0005) were significantly higher in serum compared with plasma, whereas total CO2 (P = 0.02) and globulin (P = 0.007) were significantly lower in serum compared with plasma. Serum total protein was lower than plasma levels, but it was not significant (P = 0.05). In hyacinth macaws, total protein (P = 0.02) and the albumin:globulin ratio (P = 0.02) were significantly lower in serum compared with plasma. Although statistically significant, these differences were small and appear unlikely to be of any clinical relevance. There is minimal loss of plasma volume from heparinized blood samples compared with serum volume from clotted blood samples. This allows collection of smaller blood volumes from small or sick birds in a single lithium heparin anticoagulant tube to perform a hemogram on whole blood and a biochemical profile on the separated plasma that provides values similar to those of serum.