A Holstein heifer approximately 6 months old (the only sick animal in a pen of 6 calves) presents in sternal recumbency and a state of severe depression. According to the farmer, the animal showed no symptoms until 2-3 days ago, when she began eating little and stopped ruminating.
The medical history indicates she was vaccinated with an intranasal vaccine (PI3v + BRSv + Coronavirus) at birth; vaccinated and boosted with a parenteral vaccine (PI3v + BRSv + Mannheimia) at 15 and 40 days of age; and treated with Toltrazuril at three months of age for the prevention of Coccidiosis. She has never been treated with antibiotics...
