The prevalence of hypocobalaminaemia in cats with spontaneous hyperthyroidism. Academic Article uri icon


  • OBJECTIVES: To determine the prevalence of hypocobalaminaemia in cats with moderate to severe hyperthyroidism and to investigate the relationship between cobalamin status and selected haematologic parameters. METHODS: Serum cobalamin concentrations were measured in 76 spontaneously hyperthyroid cats [serum thyroxine (T(4) ) concentration 100 nmol/L] and 100 geriatric euthyroid cats. Erythrocyte and neutrophil counts in hyperthyroid cats with hypocobalaminaemia were compared with those in hyperthyroid cats with adequate serum cobalamin concentrations (290 ng/L). RESULTS: The median cobalamin concentration in hyperthyroid cats was lower than the control group (409 versus 672 ng/L; P=00040). In addition, 408% of hyperthyroid cats had subnormal serum cobalamin concentrations compared with 25% of controls (P=00336). Weak negative correlation (coefficient: -03281) was demonstrated between serum cobalamin and T(4) concentrations in the hyperthyroid population, and the median cobalamin concentration was lower in cats with T(4) above the median of 153 nmol/L compared with cats with T(4) below this value (P=00281). Hypocobalaminaemia was not associated with neutropenia or anaemia in hyperthyroid cats. CLINICAL SIGNIFICANCE: This study indicates that a substantial proportion of cats with T(4) 100 nmol/L are hypocobalaminaemic and suggests that hyperthyroidism directly or indirectly affects cobalamin uptake, excretion or utilisation in this species.

published proceedings

  • J Small Anim Pract

author list (cited authors)

  • Cook, A. K., Suchodolski, J. S., Steiner, J. M., & Robertson, J. E.

citation count

  • 16

complete list of authors

  • Cook, AK||Suchodolski, JS||Steiner, JM||Robertson, JE

publication date

  • February 2011