The most common symptoms of CRD are open mouth breathing, swelling around the head and sinuses, nose and eyes discharge. Sometimes CRD slowly spreads through the flock causing poor growth performance. The very important part of the therapy is reducing stress in the flock and the usage of proper antibiotics is very helpful.
Doxycycline is classified as a broad-spectrum antibiotic and a member of the tetracycline antibiotics group, which can penetrate the bacterial membrane and inhibit bacterial protein synthesis of a wide range of gram-negative and gram-positive bacteria. It is strongly effective against Mycoplasmas combined with E.coli.