Mycobacterial Infection is a condition affecting chickens. Avian tuberculosis is a chronic, progressive disease with no effective treatment. It spreads slowly through the flock over time. Affected birds should be isolated or depopulated to prevent spread. This comprehensive guide covers symptoms, causes, treatment, and prevention.
What It Looks Like
Look for these signs in affected birds:
Whole body: Bird gradually becomes thin despite eating; muscle mass disappears; bird becomes emaciated
General behavior: Bird sits quietly, appears unwell, and loses interest in normal activities
Comb and wattles: Normally bright red tissues become pale, dull, or grayish
Feathers: Feathers appear unkempt, lack lustre, and look neglected
Intestinal tract: Loose, watery droppings may occur if intestines are involved
Legs and joints: Bird may struggle to walk if tubercles form in joints
Likely Causes
- Infection with Mycobacterium avium subspecies avium (MAA) or other avian mycobacteria
- Transmitted through contaminated feed, water, or soil over long periods (slow-developing disease)
- Birds are natural hosts; infection accumulates in the flock over months to years
- Poor sanitation and overcrowding accelerate transmission
- Older birds more likely to show clinical signs after prolonged exposure
About This Condition
Body System Affected: General systemic infection (lymphoid organs, GI tract)
Severity Level: serious
Contagious: Yes, spreads between birds
Affected Age Groups: hens, roosters
What to Do
No effective treatment exists for avian tuberculosis in backyard poultry. Supportive care may extend life briefly but does not cure the disease. Affected birds should be isolated to prevent spread or humanely euthanized. Consult a veterinarian on humane euthanasia options.
When to See a Vet
See a vet immediately if you notice chronic weight loss, emaciation, or progressive lethargy in a bird lasting weeks. Early the cause guides isolation decisions. Necropsy (post-mortem exam) can confirm TB.
Prevention
Source birds from reputable, disease-tested breeders. Maintain excellent sanitation: clean bedding regularly, disinfect feeders and waterers often. Avoid introducing birds from unknown sources. Periodically clean and disinfect the coop (especially floors where feces accumulate). Test flocks periodically if TB is suspected in your area.
Frequently Asked Questions
Q1: Is avian TB the same as human tuberculosis?
No, they are caused by different mycobacterial species. Avian TB (Mycobacterium avium) does not cause disease in humans. However, practice good hand hygiene after handling birds or cleaning coops.
Q2: Can I eat eggs or meat from birds with avian TB?
Avian TB does not transmit through eggs or meat to humans. However, isolate affected birds to prevent flock spread. Handle carcasses carefully and wash hands thoroughly after contact.
Q3: How long does avian TB take to develop in a flock?
Avian TB develops slowly—months to years. Some birds may show no signs while serving as silent carriers. Older birds are more likely to develop clinical disease after chronic exposure.