Low-dose meningeal worm (Parelaphostrongylus tenuis) XXXX in moose (Alces alces).

@entity281 @entity1273 @entity291 @entity425
Parelaphostrongylosis has a rapid onset and is lethal in neonatal moose (Alces alces) when large numbers of third-stage Parelaphostrongylus tenuis larvae (L3) are given experimentally. Little is known, however, about the severity and prognosis of @entity281 acquired naturally by accidentally ingesting terrestrial gastropods which are rarely infected and have few larvae. To investigate the relationship between infecting dose, age of moose, and severity of disease, five @entity291 were given low doses of three to 10 L3 when five (n = 2) or 9.5 mo old (n = 3). Each of two animals initially given low doses were later challenged with a dose of 15 L3. As positive controls, two @entity291 were given doses of 15 and 30 L3, considered to be high. All five @entity291 given low doses showed abnormal locomotory signs at 20-28 days postinoculation (DPI) that progressively became more pronounced with hind @entity425 and @entity1273 . However, after 77-130 DPI, signs diminished markedly in two of these animals and disappeared in another two. Challenge @entity281 of 15 L3 given 199 days after @entity281 had no noticeable effects although an immature worm, probably resulting from the challenge, was found in the spinal cord of one animal killed 51 days later. Two positive control animals given the high doses of 15 and 30 L3 showed moderate to severe, non-resolving, locomotory signs and had to be euthanized. Results demonstrate that single, low doses of three to 10 P. tenuis L3 cause moderate disease in moose @entity291 but over time, some worms die and animals can recover. A degree of protection may develop against @entity281 .
