In Marek's disease, which nerve is commonly affected?

In Marek's disease, which nerve is commonly affected?

• A. Optic nerve
• B. Phrenic nerve
• C. Sciatic nerve
• D. Vagus nerve

Answer: (C)

Marek's disease drives infiltration of peripheral nerves by neoplastic T cells, a process that causes neuropathy known as neurolymphomatosis. The sciatic nerve is commonly affected because it is large and travels through the hind limb, making it a frequent target for lymphomatous infiltration. When the sciatic nerve is involved, birds typically develop hind limb weakness or paralysis, which is a classic clinical sign of Marek's disease. While other nerves like the optic, phrenic, or vagus can be involved in some cases, they are less commonly affected and do not account for the typical hind limb paralysis seen with this disease.

Marek's disease drives infiltration of peripheral nerves by neoplastic T cells, a process that causes neuropathy known as neurolymphomatosis. The sciatic nerve is commonly affected because it is large and travels through the hind limb, making it a frequent target for lymphomatous infiltration. When the sciatic nerve is involved, birds typically develop hind limb weakness or paralysis, which is a classic clinical sign of Marek's disease. While other nerves like the optic, phrenic, or vagus can be involved in some cases, they are less commonly affected and do not account for the typical hind limb paralysis seen with this disease.