Intestinal Helminths in Dogs and Cats of the Bermuda Islands and Their Potential Public Health Significance, with a Report of a Probable Case of Visceral Larva Migrans

Various helmlinth parasites of dogs and cats are known to develop or live in man (Echinococcus spp., Toxocara spp., Dipylidium caninurm, Ancylostonma braziliense, A. caninum, Uncinaria stenocephala, and possibly Tr'ichuris vulpis) and some are capable of causing very serious pathological conditions. Of the human infections acquired through close association with dogs and cats in the United States, England, Puerto Rico, and undoubtedly other areas, perhaps next to Echinococcus the most significant, widespread, and damaging is that known as visceral larva migrans caused by the roundworn of dogs, Toxocara canis. The roundworm of the cat, T. cati, may also be of some importance in causing this disease in man. Visceral larva migrans is primarily a disease of toddleage children who ingest soil polluted with the eggs of Toxocara. Since Toxocara does not mature in man, a paratenic host, no eggs are produced for easy diagnosis. The second stage larvae may migrate through the organ systems (liver, lungs, brain, kidneys, eyes) for several weeks and remain alive encapsulated for many months, sometimes causing petit mal attacks, blindness, and even death (Beaver, 1956). Dent (1960) and Ashton (1960) indicate that eye infections have been found following mild Toxocara infections in which symptoms were not outstanding. A usual clinical finding, even in the absence of other symptoms, is eosinophilia frequently exceeding 50 percent persisting at a high level usually for a year or more, but which may be absent in eye infections.