Mycoplasma gallisepticum in Turkeys: Respiratory Disease Signs and Management

Mycoplasma gallisepticum is a contagious bacterial pathogen of poultry that affects the respiratory tract. In turkeys, it is especially associated with infectious sinusitis, a condition that causes swelling around the infraorbital sinuses below and in front of the eyes. Compared with chickens, turkeys often develop more obvious upper respiratory signs.

MG spreads both horizontally between birds and vertically through infected breeder flocks and hatching eggs. Once a turkey or flock becomes infected, birds can remain chronic carriers even if they look better later. That carrier state is one reason outbreaks can keep returning.

In many flocks, illness is more about reduced performance and ongoing respiratory trouble than sudden high death loss. Still, disease severity can increase when birds are stressed or when other infections, dust, ammonia, crowding, or poor ventilation are also present. Your vet can help sort out whether MG is the main problem or part of a larger respiratory disease picture.

MG is caused by infection with the bacterium Mycoplasma gallisepticum. It spreads through close contact, respiratory secretions, contaminated equipment, and movement of people, crates, or other materials between groups of birds. It can also pass from infected breeder birds to poults through eggs.

Several flock conditions can make disease more likely to show up or become more severe. These include poor ventilation, ammonia buildup, dust, crowding, transport stress, weather swings, and mixing birds of different ages or unknown health status. New additions without quarantine are a common risk point.

Co-infections also matter. A turkey with MG may become much sicker if other respiratory pathogens are present at the same time. That is why your vet may look beyond MG alone and recommend broader flock evaluation before discussing treatment options.

Diagnosis starts with flock history and a hands-on exam. Your vet will look at how many birds are affected, the age of the flock, recent additions, breeder source, ventilation, mortality pattern, and whether there are classic signs like swollen sinuses and nasal discharge.

Because several turkey diseases can look similar, testing is important. Common options include real-time PCR on choanal cleft, tracheal, or sinus samples, serology for flock-level screening, and sometimes culture or isolation in specialized settings. If birds have died, necropsy can help identify sinusitis, airsacculitis, or other lesions and rule in or out competing diagnoses.

Testing strategy often depends on your goals. A small backyard flock may need a practical answer for management decisions, while a breeder or production flock may need more formal documentation and follow-up testing. Your vet can help choose the most useful and cost-conscious plan.

Prevention starts with sourcing. The most effective step is obtaining poults from breeder flocks that are monitored and documented as free of MG. In the United States, National Poultry Improvement Plan programs are an important part of breeder-flock disease control.

Strong biosecurity is the next layer. Quarantine new birds before mixing them with your flock. Avoid sharing crates, feeders, waterers, and equipment with other bird groups unless they are thoroughly cleaned and disinfected. Limit visitor traffic, use dedicated footwear and clothing, and wash hands before and after handling birds.

Daily flock management also matters. Good ventilation, lower dust, dry litter, clean water, and reduced crowding help lower respiratory stress. Keeping birds in stable age groups and avoiding unnecessary mixing can also reduce spread.

Even with careful prevention, respiratory signs can still happen. If you notice sinus swelling, discharge, or coughing, contact your vet early. Fast action can help protect the rest of the flock and guide better decisions about testing, treatment options, and future bird purchases.