Actinobacillosis usually affects the tongue in cattle, but also occasionally affects the rumen, reticulum, liver and other skeletal muscles. Caused by the bacteria Actinobacillus lignieresii, symptoms vary from tongue infected cattle showing drooling (salivation), prolapse of the tongue, firm swelling under the bottom jaw, and eventually weight loss; to rumen/reticulum infected cattle showing chronic bloating and weight loss.

Prevention is difficult. The bacteria is present in soil, and enters the body via cuts in the mouth (eg from teeth eruptions) and other parts of the gut.

Treatment involves administration of antibiotics. The best antibiotic for this infection is very specific to this group of bacteria, so diagnosis is critical to avoid unnecessary expense of administering the wrong antibiotic.