😷 Mycoplasma gallisepticum: Understanding Chronic Respiratory Disease

One of the most common—and frustrating—respiratory diseases in backyard flocks. Let’s understand MG and why it’s so persistent!

What IS Mycoplasma gallisepticum (MG)?

A bacterial infection that causes chronic respiratory disease (CRD). Unlike most bacteria, Mycoplasma has NO cell wall, making it resistant to many common antibiotics.

The Big Problem: LIFELONG CARRIERS

Birds infected with MG are carriers FOR LIFE—even after symptoms resolve. They continuously shed bacteria and can infect other birds.

Clinical Signs:

Respiratory:

🐔Foamy/watery eyes (hallmark sign!)

🐔Nasal discharge (clear or cloudy)

🐔Sneezing, coughing

🐔Swollen sinuses (puffy face)

🐔Rattling/gurgling breathing sounds

Production:

🐥Decreased egg production

🐥Poor growth in young birds

🐥Increased susceptibility to other infections

How It Spreads:

Vertical Transmission (Egg):

🐣Infected hens pass MG through eggs to chicks

🐣Major source in hatcheries without testing programs

Horizontal Transmission (Bird-to-Bird):

💦Respiratory secretions

💦Contaminated water/feed

💦Close contact required (doesn’t survive long in environment)

Diagnosis:

Requires laboratory testing—visual symptoms alone aren’t definitive. Blood tests or PCR testing available through veterinary diagnostics.

Treatment Reality:

💊Antibiotics (tylosin, tetracyclines) reduce symptoms but DON’T cure

💊Birds remain carriers after treatment

💊Symptoms may return during stress

Prevention Strategies:

PURCHASE CLEAN BIRDS

✓ Buy from NPIP-certified, MG-tested sources

✓ Ask for testing documentation

✓ Most important prevention step!

BIOSECURITY

✓ Quarantine new birds 30+ days

✓ Test before introducing to flock

✓ Don’t mix flocks

✓ Clean boots/equipment between coops

CULL INFECTED BIRDS?

Many commercial operations cull positive birds. For backyard flocks, this is a personal decision considering: will you hatch eggs? introduce new birds? sell birds/eggs?

Key Fact: Once MG enters your flock, it’s nearly impossible to eliminate without completely starting over and sanitation.

Your turn:

❓Did you know you can ask for MG-testing documentation when buying birds? 🧪

❓Is this something you would want to test your flock for if you sell chicks?

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