We established a homologous sandwich enzyme-linked immunosorbent assay (ELISA) to measure serum levels of canine ferritin. Our assay uses a rabbit anti-canine heart ferritin polyclonal antibody, and canine heart ferritin as a standard. Serum ferritin concentration in healthy dogs (n=163) was 789 ± 284 ng/ml (mean ± standard deviation), a value higher than reported previously. Confidence levels relating to repeatability, dilution and recovery for this method were high. Therefore, we believe our developed sandwich ELISA will be effective in evaluating serum levels of canine ferritin.