Cohen, B. S., E. H. Belser, C. H. Killmaster, J. W. Bowers, B. J. Irwin, M. J. Yabsley, and K. V. Miller. 2015. Epizootiology of cranial abscess disease in white-tailed deer of Georgia. Journal of Wildlife Diseases 51(3)609-618.
Abstract
Intracranial abscess disease is a reported cause of natural mortality for mature, male white-tailed deer (Odocoileus virginianus). Most cases of abscesses are associated with bacterial infection by Trueperella (Arcanobacterium) pyogenes but little else is known about the disease. We examined 7,545 white-tailed deer from 60 sites throughout Georgia (USA) for signs of cranial abscesses, the predecessor of intracranial abscesses, to model risk factors that may contribute to incidence of the disease. Factors examined included environmental factors (soil and forest type), demographic factors (deer density and male to female ratio), and individual host factors (deer gender and age). We found no cases of cranial abscesses in the 2,562 female deer examined but they were found in 91 of the 4,983 (1.8%) male deer examined. A generalized linear mixed model, treating site as a random effect, indicated the probability of a male having a cranial abscess increased with age. Adult sex ratio (male:female) at the site was also positively associated with this disease. Site-specific variables for land cover and soil types were not strongly associated with risk of the disease and a large amount of among-site variability remained. Our results suggest the high incidence of cranial abscesses in some populations could interfere with deer management strategies attempting to increase demographic representation of older males in the population. Given the relative importance of individual and local demographic factors and the remaining unexplained spatial variability, additional investigation into spatiotemporal variation of the presumed bacterial causative agent of cranial abscesses appears warranted.