Case report: fading elk syndrome in a herd of captive elk (Cervus elaphus) in the North American midwest

Authors: Boggiatto, Paola; CRAWFORD, LAUREN - Orise Fellow; KANIPE, CARLY - Orise Fellow; Palmer, Mitchell; Olsen, Steven

Submitted to: Frontiers in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2020
Publication Date: 8/21/2020
Citation: Boggiatto, P.M., Crawford, L.S., Kanipe, C., Palmer, M.V., Olsen, S.C. 2020. Case report: fading elk syndrome in a herd of captive elk (Cervus elaphus) in the North American midwest. Meeting Abstract. 7. https://doi.org/10.3389/fvets.2020.00497.
DOI: https://doi.org/10.3389/fvets.2020.00497

Interpretive Summary: The work presented here sheds light on fading elk syndrome, a seldom reported disease of elk in North America. This highly debilitating, and often fatal condition can have a detrimental effect on captive elk herds, in both in terms of production and animal loss. Diagnosis of fading elk syndrome can be difficult, and therapeutic intervention is not always successful. Fatal elk syndrome is associated with abomasal parasitism with Ostertagia parasites, a common parasite of domestic ruminants, such as cattle and sheep. To our knowledge, this is only the second report of fading elk syndrome in the United States. The information presented will be of interest to veterinarians working with wildlife ruminants, and to elk and deer producers.

Technical Abstract: Fading elk syndrome, or chronic ill-thrift of elk, is a disease associated with abomasal parasitism with Ostertagia species, of which elk appear to be particularly susceptible. While this syndrome has been extensively reported to affect wapiti-type red deer hybrids farmed in New Zealand since the mid 1980’s, there is only a single report of this disease in North America. Here we report a case of fading elk syndrome in a herd of 34 elk (Cervus elaphus) in Ames, Iowa, at the National Animal Disease Center. Following the identification of clinical signs, physical examinations were performed, blood samples collected for complete blood counts (CBC) and serum chemistries, and fecal samples were taken for fecal floats. Blood samples were also taken and submitted to the National Veterinary Service Laboratories, for infectious disease testing. Analysis of complete blood counts were unremarkable, but blood chemistry demonstrated a severe hypoalbuminemia. Fecal floatations were also unremarkable, and non-diagnostic. Histological examination of tissues collected at necropsy revealed proliferative abomasitis and nematodes consistent with Ostertagia spp. Anthelmintic treatment consisting of a combination of pour-on Cydectin® and injectable Noromectin Plus®, at double the recommended dose for cattle, showed positive results, as all remaining animals in the herd recovered. The work presented here is the first report of naturally-acquired disease in a herd of captive elk used for research and sheds light on this seldomly-reported disease in North America.