A new variant of the H5N1 bird flu — the same one that led to the death of a Louisiana man — has for first the first time been found in infected U.S. dairy cattle.

Nevada dairy cattle infected with a new bird flu strain, Type A H5N1 D1.1, raising concerns of multiple transmission channels.

The team found that animals that had the virus inoculated directly into their lungs became severely ill, whereas animals that were infected through the nose or oesophagus did not. All animals infected with the virus still shed infectious virus particles, meaning they could infect other animals.