The range paralysis stance describes a bird in sternal recumbency with one leg forward and one leg back and is often associated with which disease?

The range paralysis stance describes a bird in sternal recumbency with one leg forward and one leg back and is often associated with which disease?

• A. Newcastle Disease
• B. Avian Influenza
• C. Marek's Disease
• D. Lymphoid Leukosis

Answer: (C)

Range paralysis stance is a hallmark of hindlimb neuropathy caused by Marek’s disease. The disease is a herpesvirus infection that leads to infiltration and transformation of nerve-associated lymphoid tissue, especially in peripheral nerves like the sciatic nerve. When these nerves are affected, the bird cannot support normal leg movement, so it often sits in sternum recumbency with one leg forward and the other back—the range paralysis posture. This neurological pattern is most characteristically linked to Marek’s disease, particularly in young chickens. Though other infections can cause nervous signs, the particular posture described is most strongly aligned with Marek’s disease due to its tendency to produce nerve involvement and paralytic gait.

Range paralysis stance is a hallmark of hindlimb neuropathy caused by Marek’s disease. The disease is a herpesvirus infection that leads to infiltration and transformation of nerve-associated lymphoid tissue, especially in peripheral nerves like the sciatic nerve. When these nerves are affected, the bird cannot support normal leg movement, so it often sits in sternum recumbency with one leg forward and the other back—the range paralysis posture. This neurological pattern is most characteristically linked to Marek’s disease, particularly in young chickens.

Though other infections can cause nervous signs, the particular posture described is most strongly aligned with Marek’s disease due to its tendency to produce nerve involvement and paralytic gait.