To determine whether or not dogs develop a deficiency of ascorbic acid during hospitalisation in an intensive care unit.


Blood samples were collected daily for up to three days from dogs hospitalised in an intensive care unit for 36 to 72 hours (n = 16) or ê72 hours (n = 20) and from healthy dogs (n = 13). Plasma total ascorbic acid concentrations were measured using a colorimetric method involving a reaction between ascorbic acid, 2,6 dichlorophenol-indophenol, thiourea and dinitrophenyl hydrazine. Additionally, clinical data were recorded for each patient.


Dogs hospitalised for ê72 hours had significantly greater plasma ascorbic acid concentrations on day 3 compared to days 1 and 2. There was no difference in plasma ascorbic acid concentrations between days 1 and 2 for dogs hospitalised for 36 to 72 hours. Plasma ascorbic acid concentrations were significantly greater for each day of sampling for the hospitalised dogs compared to the control dogs.

Clinical Significance

Plasma ascorbic acid concentrations appear to increase during hospitalisation, and supplementation may not be indicated in dogs hospitalised in an intensive care unit.