02/05/2026
Part 7 and the last of our series on common poultry vaccines
🦠 Mycoplasma: What You Need to Know 🐔
Mycoplasma (most commonly Mycoplasma gallisepticum and Mycoplasma synoviae) is a bacterial infection that is very common in backyard flocks. FINALLY! A bacteria, right?! This must be easier to treat and manage than all of those viruses we have been learning about- wrong!
Here’s the part people don’t always realize 👇
➡️ Once a chicken has mycoplasma, they carry it for life. 😟
That bird may look perfectly healthy, but it can still spread the infection (as a carrier)—especially during times of stress. (Think shipping, molt, weather changes, changing pens, or adding new birds to the pen)
Common signs include:
-Sneezing
-Nasal discharge
-Foamy or bubbly eyes
-Swollen sinuses
-Congested or “rattly” breathing
-Drop in egg production or thin shells
💊 What about antibiotics for bacteria?
Antibiotics can reduce symptoms and help birds feel better, but they do not cure mycoplasma. The symptoms can last 3 to 5 weeks, so it can really damage your program and weaken your birds. Treated birds are still carriers. Tylan is a commonly used antibiotic, but you could also use doxycycline or erythromycin if you have access to it. (Check Twin City or Rogiers as these all now require a prescription, including Tylan, which we used to be able to get at TSC).

How does it spread?
-Bird-to-bird contact
-Shared feeders/waterers (can live a few days on surfaces)
-Hatching eggs (vertical transmission - hen to chick)
-Introducing new birds
💉 The vaccine is 0.5 ml injected behind the neck and recommended at one week and a booster at 4 weeks. This is the only vaccine I have given to date. I have found giving so much serum to such a tiny silkie body can unalive them very quickly. 😭 I now give my vaccines around one month with a repeat at two months and to all new birds following a 14 to 30 day quarantine to monitor for any sickness.
You want to be certain to quarantine any new bird as the stress of a new environment or shipping can trigger a flareup if they have been infected.

📌 Bottom line:
Mycoplasma is common, lifelong, and manageable - but not curable.
Feel free to share because informed chicken tenders make healthier flocks. 🐓❤️
Infographic sourced from google
What is your experience with Mycoplasma or chronic respiratory disease? Or symptoms you weren’t sure of…