The acid-base disturbances in Canine Parvoviral Enteritis (CPV) are not well described. In addition the mechanisms causing these perturbations have not been fully elucidated. The purpose of this study was to assess acid-base changes in puppies suffering from Canine Parvoviral Enteritis (CPV) using a Modified Strong Ion Model (SIM). The hypothesis of this study was that severe acid-base disturbances would be present and that the SIM would provide patho-mechanistic insights that would not be fully appreciated by the Henderson-Hasselbalch model. The study retrospectively analysed data obtained from 42 puppies with confirmed CPV and 12 healthy controls. The CPV group had been allocated a clinical score to allow classification of the data according to clinical severity. The effects of changes in free water, chloride, lactate, albumin and phosphate were calculated using a modification of the base excess algorithm. The data for each of these variables was compared to the control group. When the data were summated for each patient and correlated to each individual component, the most important contributor to the metabolic acid-base changes according to SIM was chloride (P < 0.001). Severely affected animals tended to have a hypochloraemic alkalosis, whereas mildly effected puppies had a hyperchloraemic acidosis (P = 0.0023). In conclusion the acid base disturbances in CPV are multifactorial and complex and the SIM provides more information regarding the origin of these changes. / Dissertation (MMedVet)--University of Pretoria, 2013. / gm2014 / Companion Animal Clinical Studies / unrestricted