Tuberculosis Control Program 4-H Veterinary Science Extension Veterinary Medicine Texas AgriLife Extension Service College of Veterinary Medicine and Biomedical Sciences Texas A&M System

Objectives Discuss the decrease in the prevalence of tuberculosis in cattle Understand that health regulations are health management practices used to prevent the spread of disease

Bacterial disease of cattle Mycobacterium bovis Reportable Zoonotic

Causative Agent Bacteria Strain Mycobacterium bovis Bacteria not resilient in environment Dry conditions (2 weeks) Moist conditions (2 months)

Transmission Exit from cattle Exhale (aerosol) Milk Saliva Environmental contamination

Entry to cattle (direct contact)‏ Inhale (aerosol)‏ Increase risk in confinement Ingest (milk)‏ Entry to cattle (indirect contact)‏ Ingest (shared water systems)‏ Saliva Ingest (contaminated soil)‏

Incubation period 8 to 60 days Bacteria difficult to diagnose because it multiplies slowly Once every 20 hours

Diagnosis Clinical symptoms (advanced cases)‏ Chronic emaciation Respiratory distress Clinical symptoms (mild cases)‏ None

Post mortem/slaughter findings Nodules/lesions (tubercles, abscesses)‏ ▪ Lungs ▪ Lymph nodes ▪ Abdominal organs ▪ Reproductive organs ▪ Nervous system ▪ Bone

Tubercles

Cheese-pus Lesion in Lymph Nodes of Lungs

Test with Tuberculin skin tests (caudal fold, cervical) Post mortem test Serological test Results known 72 hours later (skin test) Positive result reads as swelling in injection area If positive, more tests needed

Prevention Ways to prevent TB Closed herds TB-free herds Test new animals Maintain fences Cooperate with state officials

Regulation and Eradication 1917—Cooperative State-Federal TB Eradication Program established USDA-APHIS State animal health agencies U.S. livestock producers

Depopulate quarantined herds Surveillance program Slaughter lesions Voluntary herd-testing program Herd accredited-free

Interstate movement testing requirement Interstate breeding cattle Identification and test Interstate feeder cattle Identification (pending) Interstate livestock shows testing requirement

Nearly eradicated in U.S. Texas status Modified-accredited-advanced Texas FEAD Emergency Response Plan Identify positive animals and destroy Reduce amount of time to get test results Track origin of suspect animals