Comparison of Electrophoretic and Bromocresol Green Albumin Methods in Chickens and Other Veterinary Species

The bromocresol green albumin assay (ALB_BCG) has been used in birds and reportedly is noncomparable with electrophoretic albumin (ALB_PE) in many species. It is accepted for use in some species and rejected in others.

We aimed to compare the performance of ALB_PE and ALB_BCG methods within backyard chickens and compare the performance of ALB_BCG in chickens with other veterinary species where the ALB_BCG method is accepted and used clinically.

Chicken plasma collected during reference interval development and samples submitted for diagnostic biochemistry profile were evaluated using the ALB_BCG and ALB_PE assays. Method comparison was performed according to current recommendations, including the use of Passing-Bablok and Bland-Altman analysis. ALB_BCG and ALB_PE were also measured in other avian species, dogs, cats, horses, and domestic ruminants. Method comparison was evaluated within and between species, including clinical utility based on the percentage of cases discordantly interpreted as hypo-, normo-, or hyperalbuminemic by ALB_BCG and ALB_PE.

In chickens, ALB_BCG and ALB_PE were not comparable, having a constant bias (-0.4 g/dL) and proportional bias. Similarly, the methods were not comparable in other species; > 10% of samples had > TE_A (15%) difference in all species. The clinical utility of albumin interpretation in chickens did not differ significantly from that in dogs and horses, as determined by ANOVA.

The data suggest that ALB_BCG is not comparable with ALB_PE and performs similarly across all tested species. There is no evidence to support the continued rejection of the ALB_BCG in chicken and other avians and acceptance in some mammals.