Since early 2024, a different kind of flu called bird flu, formally known as avian influenza, has been spreading in birds as well as in cattle. The viruses that cause seasonal flu and bird flu are distinct but still closely related. Just as swine flu strains tend to infect pigs, avian flu strains tend to infect birds. Seasonal flu versus bird fluDifferent strains of influenza A and influenza B emerge each year from about October to May as seasonal flu. Then, on April 1, 2024, health officials in Texas reported the first case of a person catching bird flu from infected cattle.