Though it was originally thought that Leghorn chickens were resistant to J virus this may be incorrect. Mortality due to tumors which may have been caused by J viruses has been recognized recently in leghorn chickens. Stress may be important in the severity of disease caused by J virus. As this is a viral infection it cannot be treated. No vaccines against J virus are available.
Correct diagnosis is important.
Isolation and identification of the virus can only be done by a very few laboratories. However, the pattern and types of tumors in an affected flock is generally very suggestive of J virus infection. Sometimes to correctly identify the type of tumor, microscopic studies in a laboratory are needed. Primary breeders are working to eradicate J virus from their stocks using the methods described in the introduction but this is not a simple task. The tests required to identify infected hens are complex and expensive.