If another calf or two die the next day, Histophilus somni (H. somni) could be the culprit, and it’s time to call your veterinarian. While some other pneumonias will surface 10 to 14 days after cattle arrive to the feedyard, H. somni affects cattle 30 to 60 days after shipping. Historically, the Northwest and Midwest accounted for the bulk of H. somni cases, but today it can be found throughout the US. Management is keyMedications to prevent or treat H. somni are limited. Other interventionsAs noted previously, medical treatment is limited for H. somni, but there are some pro-active options.