Absence of tuberculosis in free-ranging deer in Nebraska

Area of Science:

• Veterinary Pathology
• Wildlife Disease Surveillance
• Microbiology

Background:

• Tuberculosis (TB) is a significant disease in wildlife populations.
• Deer species, including white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus), can be reservoirs for TB.
• Monitoring TB in free-ranging wildlife is crucial for disease management.

Purpose of the Study:

• To investigate the presence of tuberculoid lesions in white-tailed deer and mule deer lymph nodes in Nebraska.
• To determine if Mycobacterium bovis, the primary cause of bovine TB, was responsible for observed lesions.

Main Methods:

• Microscopic examination of lymph nodes from 271 deer for tuberculoid lesions.
• Histological analysis using Zeihl-Neelson acid-fast stains.
• Molecular detection of Mycobacterium bovis using polymerase chain reactions (PCR) with specific probes.

Main Results:

• Tuberculoid lesions were identified in at least one lymph node in 12 out of 271 examined deer.
• Zeihl-Neelson staining and M. bovis specific PCR assays did not detect evidence of tuberculosis.
• The observed granulomatous lesions were attributed to causes other than M. bovis.

Conclusions:

• While tuberculoid lesions were present in some Nebraska deer, tuberculosis was not confirmed.
• The findings suggest that other bacterial agents are likely responsible for the observed granulomatous inflammation in these deer.
• Further research may be needed to identify the specific causative agents of these non-tuberculous lesions.