Mycoplasmosis in Backyard Poultry Flocks

Mycoplasmosis is a contagious disease in game birds and poultry caused by a bacteria-like organism. The specific Mycoplasmas of concern to backyard flocks include Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS). These organisms have the ability to infect many different avian species including chickens, turkeys, quail, pheasant, and even certain wild birds. Just one infected bird brought onto the premises could potentially infect certain other types of poultry on the farm.

Symptoms

A Mycoplasma infection can be difficult to detect because it may not present any obvious symptoms. The infected bird or flock can appear quite healthy for long periods of time until a stressor such as heat, unsanitary conditions, or other concurrent viral infections causes the disease to manifest itself. Under these circumstances, MG usually will cause some form of respiratory distress symptoms, including nasal discharge, mouth breathing, ruffled feathers, or poor overall performance. MS often causes swollen hock joints due to tendonitis and subsequent leg problems or bursitis in the breast region. In many cases, you will simply experience a nagging mortality problem and/or “poor doing” birds. This disease was such a problem to the poultry industry in years past that a major effort was implemented to eradicate the pathogen from commercial flocks.

Treatment

Part of the concern about Mycoplasmas is that once a bird becomes infected, it typically remains a carrier for life. You can treat the bird with antibiotics to help it recover during stress periods, but treatment will not eliminate the organism. This means you will either have to live with the infection or euthanize the birds or flock to eradicate it. If you opt to live with the disease, you could try separating infected birds from the rest of the flock to help prevent infection of any clean birds you may have, but this usually fails in the long run. The disease ultimately will result in lost performance and cost you more money, so it is not something to take lightly. Never sell or give infected birds away to another individual because you will only be passing the problem to someone else. Unfortunately, many producers are unknowingly doing this.

Transmission

This disease spreads by direct contact or egg transmission. Although egg transmission does occur, clean birds coming in contact with infected birds or contaminated equipment is the more common method of spread. Usually birds need to be in close contact to spread the disease from bird to bird, but this may not always be the case. Due to the risk of transmission, always change your clothes and shoes and wash your hands before tending to your birds if you have gone to a sale or visited another flock. MG and MS are readily destroyed by common disinfectants, so always make sure any shared equipment or coops are cleaned before allowing them back onto your farm. Obviously, do not sell or give chicks to others if you are aware of mycoplasmosis in your flock.

Reducing the Risk

The best way to avoid infection is to make sure you do not bring any infected birds onto your farm. A simple blood test can determine whether a bird is infected with MG or MS, so it is in your best interest to always test birds/flocks before acquiring them. If you are experiencing any of the aforementioned signs in your birds, test them to diagnose whether you have an MG or MS infection in your current flock. Remember, this disease is present in many backyard flocks, and you cannot afford to let your guard down concerning the health of your flock.

By Dr. Timothy S. Cummings, Clinical Poultry Professor
Information Sheet 1659 - Mississippi State University Extension Services