Gastritis in sows due to Hyostrongylus rubidus--in one case associated with Balantidium coli.

Three cases of gastritis in sows due to the stomach worm Hyostrongylus rubidus are described. This disease has not previously been reported from the Scandinavian countries. Diffuse gastritis and extreme emaciation were the essential findings at necropsy in all 3 cases. In 2 animals the gastric changes consisted of diffuse nodular hyperplasia of the mucosa. In the third case similar hyperplastic changes were present, but these were largely obscured by a superimposed extensive diphtheresis of the mucosa. The gastric changes in cases of hyostrongylosis reported in the literature and the conceptions regarding their pathogenesis are reviewed and discussed. In the sow with diphtheroid gastritis large numbers of Balantidium coli, in addition to H. rubidus, were present in the altered stomach mucosa. It is assumed that the gastritis due to H. rubidus has resulted in gastric hypochlorhydria thus creating an environment of sufficiently low acidity for ingested Balantidium spp. to live and multiply. Whether this parasite has participated in the development of the gastric diphtheresis is impossible to ascertain.