Via Emerging Microbes & Infections: First documented case of avian influenza (H5N1) virus infection in a lion. The conclusion:
In summary, we documented the first infection of a lion with a highly pathogenic H5N1 AIV, expanding the host range of AIV. This virus was a reassortant from circulating H5N1/H9N2 viruses and remained prevalent among poultry. Since this virus was highly virulent to the lion and that AIV has been reported to cause deaths in tigers and leopards, we believe that captive animals are under certain risk of AIV infections, and increased surveillance is needed to track and chart the ongoing evolution of circulating AIV with respect to their potential to infect susceptible mammalian hosts.
