User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-6974847-20130729183655

Frontier's Rathian Subspecies - just what.

I think I might have the answer. Goa Magara has "hair" to host the virus in a positive way, Rathian has some hair-like spikes so maybe it is just a Rathian with the virus and it has adapted to it.

But in MH4, some Rathian die because of the virus. It probily was in a weak state, Pregnant, or just unaware it had the virus and it was too late to do anything.