Seasonal vitamin D status of Greyhounds in Sydney

OBJECTIVES: To survey the vitamin D status of a population of Greyhounds in New South Wales, and to establish a reference range for plasma 25(OH)D. To investigate whether any seasonal fluctuation in vitamin D status is detectable in these animals. DESIGN: Vitamin D status was assessed in Greyhounds and crossbred dogs presented to the University of Sydney for teaching purposes over a 24 month period. PROCEDURES: Plasma 25(OH)D concentration was measured as an estimate of vitamin D status. Physical examination and plasma calcium concentration were used to verify the health of the animals, particularly with respect to metabolic bone disease. RESULTS: A plasma 25(OH)D concentration range of 10 to 76 nmol/L was found in healthy adult Greyhounds. There was no sex- or season-dependent variation in vitamin D status in Greyhounds. Concentrations in crossbred dogs did not differ significantly from those in Greyhounds. CONCLUSION: The reference range for plasma 25(OH)D concentration in Greyhound dogs is similar to that previously reported for humans. It would seem that healthy dogs in the Sydney region do not exhibit a seasonal fluctuation in their vitamin D status.