Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 24, 1998
Publication Date: N/A
Interpretive Summary: This brief communication describes a case report in which pregnant white-tailed deer died suddenly of pneumonia after capture at a commercial hunting preserve and transport to an animal disease research facility. In the process of capture and transport, deer were unavoidably subjected to various stressors including capture, confinement in a trailer for up to 24 hours, transport to the research laboratory, and introduction to new surroundings. After arrival, over a period of 14 days, 6 of 38 deer died suddenly from pneumonia caused by a bacterium generally considered to be of low disease causing ability. The fatal pneumonia in these deer was likely due to the combined effects of numerous stress factors, which caused decreased resistance to disease in these animals. This report emphasizes the profound effect of stress on wild and semi-wild animals. This case report will be of interest to wildlife officials, zoo and wildlife veterinarians, scientists engaged in research involving wildlife, producer of deer and other wildlife species, and others involved in capture and transport of wildlife.
Technical Abstract: Pregnant white-tailed deer(Odocoileus virginianus) were purchased from a commercial hunting preserve to be used in a research project. Deer were darted for chemical immobilization, confined in a stock trailer for up to 24 hours, transported 410 miles to the research laboratory, and introduced to new surroundings and social structures. Five to seven days after arrival, several deer developed lameness with associated swelling of one o both distal hindlimbs. Lame deer were reluctant to rise when approached, but otherwise exhibited no clinical signs of systemic illness. Over a period of 14 days, 6 deer died suddenly. Postmortem examinations of all deer revealed diffuse fibrinopurulent pleuritis and pericarditis with multifocal pulmonary necrosis and abscessation. Rear limb swelling was due to diffuse subcutaneous edema, necrosis, and hemorrhage with multifocal abscessation. Microscopic lesions in the lung and foot were characterized by multifocal coagulative necrosis with abscess formation and colonies of Gram positive bacilli. Bacteriologic culture of lung and pleural fluid yielded Actinomyces pyogenes from 5 of 6 deer. Various bacteria (E. coli, streptococci, and staphylococci) were isolated from lesions in the foot. Stress-induced pneumonia due to A. pyogenes has been described in other wild animal species such as bighorn sheep. Foot abscesses caused by A. pyogenes, with dissemination of disease to other sites, including the lung, has been described in newly captured deer. The impact of stress on disease resistance in wild or semi-wild animals should not be underestimated.