犬におけるライオン回虫の自然感染について附.犬への人工感染

抄録

In 1958, Toxascaris leonina infection was observed among dogs in Tokyo. The authors obtained this parasite from the intestines of three of six dogs killed for autopsy. Prior to the autopsy these dogs have been kept in a medical school. For a large number of dogs kept there was carried out parasitological examination. Of 112 dogs examined in 1959, 19 (17%) were found infected or egg-positive in the feces, and of 64 examined in 1960, 6 (9.4%) infected. These dogs were mongrels presumed to be more than one year old and weighing 10 to 25 kg. Toxocara canis was observed only in two apparently young dogs, one of which was infected concurrently with T. leonina.
In 1960, another canine case of T. leonina infection was observed. It was a Scotch terrier. 4 months old, born and reared in Tokyo. It was also infected with T. canis.
The authors think that most of the reports on theoccurrence of T. canis in adult dogs are possibly meager information on T. leonina, and that some researchers referred an ascarid, which is really T. leonina, erroneously as T. canis.
The authors have successfully infected dogs by feeding them embryonated eggs involved in natural infection. A larva (of the 2 nd stage) was observed ensheathed at 5 days of incubation. The sheath was kept on for 40 days of incubation. In the case of feeding dogs with embryonated eggs, the prepatent period, or a period from infection to the appearance of eggs in the host feces, was in a range of from 48 to 88 days.