Abstract
Young adult forms of Dirofilaria immitis were found in the brains of 2 dogs (Nos. 1 and 2) which died after manifesting such neurological symptoms as depression, dullness and ataxia, and in the right dorsal cerebral vein of a dog (No. 3) which had shown no clinical signs. Pathological and parasitological studies were made on these cases. The results obtained are summarized as follows. 1) Macroscopically, a worm was found in the crus cerebri of Dog 1 and another in the medulla of the gyrus ectosylvius of the left cerebral hemisphere of Dog 2. Neuropathological findings consisted primarily of traumatic destruction and multiple hemorrhagic malacia caused directly by the worm, and secondarily of degeneration of nerve fibers as swelling or disappearance of axis cylinders and myelin sheaths. In Dog 3, a worm was found in the right dorsal cerebral vein, and a malacic lesion with hemosiderosis in the left piriform lobe. There may probably be a relationship between the worm and the malacic lesion. 2) Parasitological examination revealed that all the worms obtained from the brains were young adult forms of Dirofilaria immitis (Leidy, 1856). The worm collected from Dog 1 was female and those from the others were male. 3) For the present disease is distinguishable from ordinary dirofilariasis, the new name Cerebral dirofilariasis was proposed.
