Generalized unthriftiness, loose stool, chronic wasting, and subsequent death have been observed for more than a decade in mule deer and pronghorn feeding on specific alfalfa pastures in Humboldt County in northern Nevada. The condition appears to affect young animals and females more severely than adult males and results in moderate to high rates of debility and mortality in resident herds. The affected herds appear to feed exclusively on alfalfa pasture and tend to be found on these areas year-round.

Despite several investigations since 1998, no definitive diagnosis has been made. However, following recent discussions and the establishment of a stronger collaborative relationship, we [veterinarians and scientists with the University of Nevada, Reno (UNR), Nevada Department of Wildlife (NDOW), and the Nevada Department of Agriculture (NDOA]) believe that it might now be possible to define the causes of this problem. This pilot investigation will collect clinical data for use in formulating a tentative explanation of pathogenesis.

Mule deer and Pronghorn antelope are both important big game species in Nevada. When natural events, environmental changes or anthropogenic factors negatively affect the health and success of game populations in the state, it is essential that investigations are initiated that accurately and scientifically investigate possible causes.

Lack of funding and qualified personnel has hampered previous efforts to determine the cause of this problem. As a result, no mitigation strategies have been proposed for a widely recognized and routinely occurring wildlife health concern. Because of recent efforts to improve cooperation and collaboration, a multi-disciplinary team of qualified veterinary and scientific personnel has now been assembled.

The goal of this project is to prove the working hypothesis as follows:

1. The cause of generalized unthriftiness is due to primary or secondary copper deficiency (and/or selenium deficiency).
2. Chronic diarrhea may result directly from these deficiencies or may develop secondary to the exclusive alfalfa diet (high energy and protein, low structural fiber.)