The effects of dehydration on the radiologic and pathologic appearance of experimental canine segmental pneumonia.

In an attempt to determine whether dehydration (intravascular fluid depletion) alters the radiologic or histologic picture of segmental Streptococcus pneumoniae pneumonia, we induced pneumonia in 2 groups of dogs, group 1 (normally hydrated) and group 2 (dehydrated). Five hours after the intrabronchial instillation of a brain-heart-Streptococcus pneumoniae mixture, all chest radiographs of dogs in group 1 and 2 were compatible with segmental alveolar pneumonia. Histologic lung sections obtained as early as 2.5 hours after infusion of the brain-heart-Streptococcus pneumoniae mixture revealed intra-alveolar edema with a minimum of leukocytes. By 24 hours after infusion, both groups showed marked intra-alveolar collections of edema fluid, fibrin, and leukocytes. We conclude that in a canine model, moderate dehydration has no effect on the radiologic or histologic features of Streptococcus pneumoniae pneumonia.