Necropsy findings in 62 opportunistically collected free-ranging moose (Alces alces) from Minnesota, USA (2003-13).
The Minnesota, US moose population has declined dramatically since the 1990s. All 54 carcasses of moose that died of unknown cause or were euthanized by gun shot by tribal or Department of Natural Resources personnel because of perceived signs of illness between 2003 and 2013 and eight carcasses of moose that died from vehicular accidents between 2009 and 2013 were submitted to the Minnesota Veterinary Diagnostic Laboratory and included in our study. The majority of the animals were underweight or cachectic (n = 53; 85%). Neural migration presumably by Parelaphostrongylus tenuis was a common finding (n = 28; 45%). Moderate to marked Dermacentor albipictus ("winter tick") ectoparasitism with widespread alopecia was the cause or a contributing cause of death in 14 (23%) cases in which grossly apparent anemia was associated with exhaustion of hepatic iron stores. Hepatic lesions associated with Fascioloides magna were common (n = 37; 60%) but were unlikely to be the cause of death. Environmental factors favoring winter tick survival, habitat expansion of white-tailed deer (Odocoileus virginianus), and the survival of terrestrial and aquatic snails (serving as intermediate hosts for P. tenuis and F. magna), might contribute to the seemingly severe parasitic burden in Minnesota's moose population.
1 Department of Veterinary Population Medicine, Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Minnesota, 1333 Gortner Ave., St. Paul, Minnesota 55108, USA.
Arno
A
Wünschmann
Anibal G
AG
Armien
Erika
E
Butler
Mike
M
Schrage
Bert
B
Stromberg
Jeff B
JB
Bender
Anna M
AM
Firshman
Michelle
M
Carstensen
D000820:Animal Diseases / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D000818:Animals; D001424:Bacterial Infections / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology / Q000662:veterinary; D003670:Deer; D005260:Female; D008297:Male; D008910:Minnesota / Q000453:epidemiology; D010273:Parasitic Diseases, Animal / Q000453:epidemiology / Q000473:pathology; D012621:Seasons; D014947:Wounds and Injuries / Q000473:pathology / Q000662:veterinary
Alces alces; Dermacentor albipictus; Fascioloides magna; Minnesota; Parelaphostrongylus tenuis; moose; parasites