Cheryl M. Bartlett

Filarioid nematodes (Filarioidea: Onchocercidae) of Corvus brachyrhynchos brachyrhynchos Brehm in southern Ontario, Canada and a consideration of the epizootiology of avian filariasis

SummaryChandlerella chitwoodae Anderson, 1961 (prevalence 65%), Splendidofilaria caperata Hibler, 1964 (21%), Eufilaria longicaudata Hibler, 1964 (15.5%), C. quiscali (von Linstow, 1904) Robinson, 1971 (1.9%), Cardiofilaria pavlovskyi Strom, 1937 (0.4%) and Splendidofilaria wehri (0.3%) were found in crows (Corvus brachyrhynchos brachyrhynchos Brehm) wintering in southern Ontario, Canada. S. caperata, E. longicaudata, Cardiofilaria pavlovskyi and S. wehri are reported for the first time from this host.Infection with Chandlerella chitwoodae and E. longicaudata produced microfilaraemias and these two common species apparently are maintained in the crow population. Infection with S. caperata was amicrofilaraemic (occult) and this common species cannot, therefore, be maintained in the crow population. C. quiscali, Cardiofilaria pavlovskyi and S. wehri occurred infrequently and must be common parasites of other woodland bird species. The presence of both common and sporadic infections in crows suggests that some avian filarioids parasitize numerous birds sharing a particular habitat. However, some host species are probably more important than others in maintaining infections within an avian community.The hosts of each species in Chandlerella, Splendidofilaria, Cardiofilaria and Eufilaria are listed. Chandlerella flexivaginalis (Jones, 1961) Sultana, 1962 and C. hispanica López-Caballero, 1974 are placed in synonymy with C. chitwoodae. Splendidofilarioides Freitas & Ibáñez, 1968 is made a synonym of Splendidofilaria and the type species becomes Splendidofilaria pachacuteci (Freitas & Ibáñez, 1968) n. comb. S. passerina Koch & Huizinga, 1971 is synonymized with S. algonquinensis (Anderson, 1955) Anderson, 1961. Pseudaproctella andersoni var. major Chabaud, Brygoo & Richard, 1964 and Cardiofilaria chabaudi Dissanaike & Fernando, 1965 are placed in synonymy with C. major Dissanaike & Fernando, 1965. Eufilaria cypseli (Annett, Dutton & Elliot, 1901) Nelson, 1966 is transferred to Lemdana as L. cypseli (Annett, Dutton & Elliot, 1901) n. comb. E. buckleyi (Desmukh, 1968) n. comb. is designated for Neofilaria buckleyi Desmukh, 1968 (= Eufilaria utae Anderson & Bain, 1976). ac]19800116

UNUSUAL FINDING OF ENCAPSULATED NEMATODE LARVAE (SPIRUROIDEA) IN BARTRAMIA LONGICAUDA AND NUMENIUS AMERICANUS(CHARADRIIFORMES) IN WESTERN CANADA

Third-stage spiruroid larvae were found encapsulated on the serosa of the small and large intestines and in the mesentery of one of 15 adult upland sandpipers (Bartramia longicauda) from Manitoba, Canada, and three of 18 adult long-billed curlews (Numenius americanus) from Alberta, Canada. The larvae resemble third-stage larvae of Physocephalus sexalatus and birds may serve as a paratenic host of this unidentified spiruroid species.

PATHOLOGY AND EPIZOOTIOLOGY OF DIROFILARIA SCAPICEPS (LEIDY, 1886) (NEMATODA: FILARIOIDEA) IN SYLVILAGUS FLORIDANUS (J. A. ALLEN) AND LEPUS AMERICANUS ERXLEBEN

Dirofilaria scapiceps was found between the synovial sheath and tendons, i.e., within the tendon sheath, in the ankle region of eastern cottontail rabbits (Sylvilagus floridanus) and snowshoe hares (Lepus americanus). In cottontail rabbits, tendons and sheaths appeared normal and all worms were adults. Only one (4%) of 24 infected rabbits contained dead worms. All female worms were gravid in rabbits killed in late winter or early spring. Microfilaremias in rabbits were high (approximately 30–100 microfilariae/60 μl blood) and of long duration (at least 8–28 mo), and rabbits were considered normal hosts of D. scapiceps. In some snowshoe hares, tendons and sheaths also appeared normal; however, in other hares a chronic proliferative tenosynovitis, characterized by fibrinous exudate, hyperplasia and hypertrophy of the intima and inflammatory cell (predominantly lymphocytes and plasma cells) infiltration of the intimal and fibrous layers of the synovial sheath led to encapsulation of worms. Dead subadult, dead adult, and live adult worms were found in the ankles of hares; 86 (46%) of 186 infected hares contained some or only dead worms. Fibrosis commonly occurred around dead worms. Dead subadults were also found in subcutaneous connective tissues over the trunk of the body. Degenerate embryos and amorphous material were observed in uteri of some female worms in hares killed in late winter or early spring. Few (1–5 microfilariae/60 μl blood) or no microfilariae were observed in the peripheral blood of hares and microfilaremias were of short duration (less than 8 mo). Microfilariae in hares are probably trapped and destroyed in the chronic inflammatory lesions in the tendon sheaths since normal, degenerate, and calcified microfilariae were observed in the capsules around adult worms. Some microfilariae might also be destroyed in lymph nodes. Although D. scapiceps can be maintained within snowshoe hare populations, hares are considered abnormal hosts of D. scapiceps. Dirofilaria scapiceps may have spread from cottontail rabbits to snowshoe hares relatively recently.

OCCULT FILARIASIS IN CROWS (Corvus brachyrhynchos brachyrhynchos BREHM) INFECTED WITH Splendidofilaria caperata HIBLER, 1964 (NEMATODA: FILARIOIDEA)

Adult Splendidofilaria caperata Hibler, 1964 were found in the tunica media of the pulmonary arteries of 21% of 341 crows (Corvus brachyrhynchos brachyrhynchos Brehm) wintering in southern Ontario, Canada. Microfilariae of S. caperata were not observed in the peripheral blood or in skin snips of infected crows. Microfilariae were rarely found in lung blood and then only in small numbers. Microfilariae were apparently overcome in the wall of the pulmonary artery; chronic inflammation was associated with their presence in arterial tissue. Crows apparently acquire S. caperata from insects that have fed on birds in which a microfilaraemia does develop.

EPIZOOTOLOGY, DEVELOPMENT, AND PATHOLOGY OF GEOPETITIA ASPICULATA WEBSTER, 1971 (NEMATODA: HABRONEMATOIDEA) IN TROPICAL BIRDS AT THE ASSINIBOINE PARK ZOO, WINNIPEG, CANADA

Geopetitia aspiculata was found in 12 species of Passeriformes, one species of Cor-aciiformes, and one species of Charadriiformes which died in a free-flight area in the Tropical House at the Assiniboine Park Zoo, Winnipeg, Canada. The nematodes occurred in chronic inflammatory cysts attached to the serosa of the posterior end of the esophagus, proventriculus, and the anterior part of the gizzard. Posterior ends of worms were observed to extend from the cyst into the lumen of the proventriculus. Birds hatched and raised in the Tropical House acquired infections, probably through the agency of feral crickets. Experimental studies showed that G. aspiculata developed to the infective third stage in the fat body of Acheta domesticus (L). This is the first transmission cycle of Geopetitia spp. to be elucidated and the egg, first, third, and early fifth stages of the parasite are described. The absence of spicules in males of G. aspiculata is confirmed. Geopetitia aspiculata was probably introduced to the Zoo by infected tropical birds obtained from dealers or other zoos. The wild source of the parasite is not known since G. aspiculata has never been reported in wild birds; the report of G. aspiculata in wild Piciformes in Cuba by Barus (1971) is in error.