Chronic Respiratory Disease (CRD) is one of the most common causes of disease in backyard poultry. It occurs when chickens and turkeys, already infected with Mycoplasma gallisepticum become stressed. The bacteria then causes major damage to the bird's respiratory system.
The baterica M. gallisepticum spreads via
A flock can become inflected with M. gallisepticum but show few or no signs of infection. When an event or change causes stress to the bird, CRD occurs.
Signs of CRD
Signs of CRD are sniffling, sneezing, coughing and other signs of respiratory distress. Birds may display symptoms more clearly when observed from a distance.
CRD can spread slowly through a flock, causing poor production and retarded growth over an extended period.
Mortality rates vary significantly within flocks.
Similar Diseases
Other diseases that cause respiratory symptoms include:
Treatment
Reducing or removing the source of stress is essential to managing the disease. There are also antibiotics that can help to control CRD once it is diagnosed.
Ask your veterinarian about testing and appropriate treatments.
Prevention
Management issues must be addressed before the birds arrive.
Ensure birds are free of M. gallisepticum on introduction.
If possible, operate an "all-in, all-out system" with thorough cleaning between batches.
Reassess flock nutrition and flock dynamics (size, age distribution, presence of roosters etc).
Reassess housing. Coops that are difficult to clean accumulates manure, dust and vermin. This can lead to many common ailments in poultry.
Vaccination against CRD is available. Ask your suppliers about the vaccination status of the birds you are acquiring.