Mycoplasma (MG / MS) vaccines
Mycoplasma gallisepticum (MG) causes chronic respiratory disease (CRD) in chickens, often made worse by E. coli; Mycoplasma synoviae (MS) causes joint swelling and eggshell problems. Both spread through the egg from infected breeders and between birds. Control relies on MG/MS-free chicks, biosecurity and, where needed, live or inactivated vaccines.
Signs to watch for
- Coughing, rattling breath, nasal discharge (MG)
- Swollen sinuses and foamy eyes
- Swollen hocks and footpads, lameness (MS)
- Eggs with thin, rough shell tips (MS)
- Poor growth and feed conversion
Which birds are at risk?
Broilers, layers and breeders; long-living layers on multi-age farms are most exposed.
How vaccination protects your flock
Live MG vaccines are given by eye drop or spray during rearing to protect layers on infected sites; inactivated vaccines are injected. MS vaccines are used where MS is a problem. Always start with mycoplasma-free chicks from tested breeder flocks.
Mycoplasma (MG / MS) vaccines from Shiv Sales
Live and inactivated options to control Mycoplasma gallisepticum and Mycoplasma synoviae.
Mycoplasma (MG / MS): common questions
What is CRD in poultry?
Chronic respiratory disease — usually Mycoplasma gallisepticum infection, often combined with E. coli — causing long-lasting respiratory illness and poor performance.
Can mycoplasma pass from hen to chick?
Yes. MG and MS can be transmitted through the egg, which is why buying chicks from tested breeder flocks matters.
Should every farm vaccinate against MG?
Not necessarily. Vaccination suits farms where MG is present, such as multi-age layer sites. Discuss testing and options with your vet.
Related guide
Biosecurity basics for every poultry farm
Vaccines protect birds that are exposed to disease. Biosecurity reduces how often they are exposed in the first place — and it costs far less than an outbreak.
Read articleCommon chicken diseases and their vaccines
Signs, affected ages and vaccines for the 12 most important poultry diseases.
Open guideOther vaccines
This page is general information for farmers and does not replace veterinary advice. Always follow the vaccine manufacturer's instructions.
Need help choosing the right vaccines?
Talk to our team for a vaccination schedule built around your flock, location and disease pressure. Consultation is free for customers.