Which viral infection is primarily transmitted by pigeons?

The viral infection primarily transmitted by pigeons is avian herpes, specifically the herpesvirus known as pigeon herpesvirus or Psittacine herpesvirus. This virus affects various bird species, but particularly pigeons and doves, where it can cause significant health issues.

Pigeons are often asymptomatic carriers of the virus, meaning they can spread it without showing any signs of illness themselves. This characteristic is crucial as it allows the virus to persist in bird populations and spread more easily. Avian herpes can manifest in infected birds as neurological symptoms and respiratory issues, among others.

In contrast, avian flu is primarily associated with waterfowl and some bird species but not specifically transmitted by pigeons. West Nile virus, while it can be found in many bird species, is primarily transmitted by mosquitoes, not directly from pigeons. Canine distemper affects carnivores and does not involve birds in its transmission cycle. Thus, the specificity of avian herpes virus transmission through pigeons makes it the correct answer to the question posed.