| dirofilaria ursi-like parasites acquired by humans in the northern united states and canada: report of two cases and brief review. | two cases of subcutaneous dirofilariasis acquired in ontario and vermont are reported. the parasites in these and eight cases previously reported from the northern united states and canada are classified as resembling dirofilaria ursi, a primarily subcutaneous parasite of bears, or d. subdermata of porcupines, in the same region. a distinguishing morphological feature of the d. ursi-like group is the presence of distinct longitudinal cuticular ridges regularly and widely spaced on the outer surf ... | 1987 | 3310687 |