THE ROUNDWORMS OF DOMESTIC SWINE, WITH SPECIAL REF- 

 ERENCE TO TWO SPECIES PARASITIC IN THE STOMACH. 



SUMMARY. 



Two species of roundworms belonging to the family Filariidse, of particular interest 

 to helminthologists and veterinarians on account of their wide distribution and fre- 

 quency of occurrence in American swine and the possibility that they may cause 

 serious injury to their host, are given special consideration in this paper. 



One of these species, identified as Spiroptera strongylina, has recently been placed 

 in a new genus, Arduenna, of which it is the type, and several errors regarding the 

 anatomy of this parasite have been corrected. Another species, Arduenna dentata, 

 has been found in China associated with Arduenna strongylina, and although not yet 

 reported in American swine is mentioned in this connection, as further investigation 

 may reveal its presence in this country. 



Arduenna strongylina is much more common in American swine than it is said to 

 be in European swine, and has been found abundantly in the slaughterhouses at St. 

 Louis, Chicago, South Omaha, and Kansas City, and has also been collected at Ben- 

 ning, D. C., and Bethesda, Md. 



Specimens of hogs' stomachs received from Chicago showed the worms deeply 

 fastened in' the submucosa or embedded in necrotic tissue near which were deep 

 ulcers. The condition suggested infection with Bacillus necrophorus, the inoculation 

 of which might easily result from the burrowing of the worms; however, owing to the 

 sterile condition of the specimens received, this could not be satisfactorily demon- 

 strated. A similar diseased condition of the stomachs of hogs in Europe is attributed 

 by Von Ratz (1899d)' to infection with Arduenna strongylina. Under the circum- 

 stances the worm should be regarded with grave suspicion, and general prophylactic 

 measures for the prevention of the spread of infection are suggested. 



Commonly associated with Arduenna strongylina in this country is another worm, 

 identified as Physocephalus sexalatus, first described by Molin (1860b) from specimens 

 from the peccary (Dicotyles labiatus) from Brazil; also found by him associated with 

 Arduenna strongylina from the wild boar in Germany. It is also reported by Von 

 Linstow (1879b) (who apparently mistook this species for Arduenna strongylina) 

 and Piana (1897e), from Europe, and by Railliet and- Henry (1911b), from Madagascar 

 and Indo-China, in the former case associated with a severe gastritis. Seurat (1912) 

 has recently reported this species from the ass and dromedary in Algeria, but his 

 statements would seem to require confirmation. 



According to the writer's experience, Physocephalus sexalatus is almost as widely 

 distributed as Arduenna strongylina, since out of eight lots of specimens of the latter 

 species, specimens of Physocephalus sexalatus were found in all but one. In a mixed 

 infection, however, it has never been found as abundantly as Arduenna strongylina. 

 This worm has apparently the same habit of injuring the mucosa as has Arduenna 

 strongylina, as both species were found in the same necrotic tissue in a hog's stomach. 

 It must therefore be considered only less dangerous because it is less abundant, and 

 should be subject to the same treatment suggested for infestation with Arduenna 

 strongylina. 



' References to literature will be found in bibliography at end of bulletin. 



