Experimental Studies of Elaphostrongylus rangiferi in Reindeer (Rangifer tarandus tarandus): Life Cycle, Pathogenesis, and Pathology

Abstract

A total of 12 reindeer calves (Rungifer tarandus tarandus) were given 200-1,000 infective larvae of Elaphostrongylus rangiferi and autopsied 24-196 days post inoculation (p.i.). The larvae penetrated venules of the abomasal wall and followed the bloodstream via the liver to the lungs. In the lungs the larvae entered pulmonary venules and spread to all tissues via the general circulation. Many larvae that lodged in arterial vessels outside the spinal cord migrated into the cord along the spinal nerves. Nematodes matured in the central nervous system (CNS), and then migrated to the skeletal muscles (SM) via the spinal nerve roots. Eggs were deposited into veins and carried via the venous blood to the lungs. Here, the first stage larvae hatched and entered the airways. Pathological lesions consisting of focal necroses and interstitial accumulations of inflammatory cells were observed in the abomasal wall, liver, lungs, myocardium and kidneys. Infarcts were observed in the myocardium, kidneys and CNS. Other lesions in the nervous system were encephalomyelitis, focal traumatic encephalomyelomalacia, axon and myelin sheath degenerations, meningitis, chorioditis, perineuritis, neuritis and ganglioradiculitis. A multifocal verminous pneumonia persisted from day 103 p.i., and nematode-induced inflammatory oedema was observed in the intermuscular connective tissue of the SM at 196 days p.i.

Epidemiological Aspects of Cerebrospinal Elaphostrongylosis in Small Ruminants in Northern Norway

“…The incidence estimates of CSE among sheep in Balsfjord (1990/91) was approximately 10 O/o of the corresponding frequency among goats. The higher incidence of CSE in goats, compared to sheep, probably reflects the lower resistance to, and higher pathogenicity of E. rungiferz in goats compared to sheep that has been found in experimental studies ; see also HANDELAND, 1994;.…”

“…Hosts are infected during grazing by ingestion of gastropods containing L3. The haematogenously from the gastrointestinal tract to the CNS where nematode development takes place and during which neurological signs occur SKORPING, 1992a, b, 1993;HANDELAND, 1994).…”

Morphometric characteristics of first stage Elaphostrongylus cervi (Nematoda: Protostrongylidae) larvae from Bulgaria

“…The infection with elaphostrongylins leads to complications and emergence of the respective clinical signs both on part of the respiratory system and on the nervous system and locomotive apparatus as well (Handeland 1994;Demiaszkiewicz et al 1999;Kutz et al 2001;Bregoli et al 2006). The economic losses in elaphostrongyloses are expressed in lowering the productivity of the animals, a reduction of the number of offspring and abortions or death of the newborns (Kontrimavichus et al 1976).…”

Experimental infection of reindeer, sheep and goats with Elaphostrongylus spp. (Nematoda, Protostrongylidae) from moose and reindeer

“…In reindeer and small ruminants, experimentally infected with E. rangiferi, traumatic lesions from migrating worms and presence of parasites in the CNS parenchyma were described by Handeland & Skorping (1992a;1992b), Handeland et ah (1993) and Handeland (1994). These shows that this species grows within the CNS tissue.…”

“…These findings supports the results from experimentally infected guinea pigs (Cavia porcellus) with E. cervi described by Olsson et ah (1998). Handeland & Skorping (1992a), studying the early migration route of E. rangiferi in goats and Handeland (1994) in reindeer, suggested that infective larvae migrated to the lungs via a porto-hepatic route. Additionally, they noted lesions in the mesenteric lymph nodes points out a complimentary, or alternative route.…”