Serum cobalamin concentrations in healthy cats and cats with non-alimentary tract illness in Australia.

To determine a reference range for serum cobalamin concentration in healthy cats in Australia using a chemiluminescent enzyme immunoassay and to prospectively investigate the prevalence of hypocobalaminaemia in cats with non-alimentary tract disease. Prospective study measuring serum cobalamin concentrations in clinically healthy cats and cats with non-alimentary tract illness. Blood was collected from 50 clinically healthy cats that were owned by staff and associates of Veterinary Specialist Services or were owned animals presented to Creek Road Cat Clinic for routine vaccination. Blood was collected from 47 cats with non-alimentary tract illness presented at either clinic. Serum cobalamin concentration was determined for each group using a chemiluminescent enzyme immunoassay. A reference range for Australian cats calculated using the central 95th percentile in the 50 clinically healthy cats was 345 to 3668 pg/mL. Median serum cobalamin concentration in 47 cats with non-alimentary tract illness (1186 pg/mL; range 117-3480) was not significantly different to the median serum cobalamin of the 50 healthy cats (1213 pg/mL, range 311-3688). Using the calculated reference range one sick cat with non-alimentary tract illness had a markedly low serum cobalamin concentration. Although hypocobalaminaemia is uncommon in sick cats with non-alimentary tract illness in Australia, its occurrence in this study warrants further investigation.