Newborn Calf Unable to Rise
History. A producer calls to ask about an Angus heifer calf born early today that has not stood. The calf makes efforts but does not seem coordinated enough to stand. The producer has fed the calf with colostrum by tube and wants her examined.
This is the second calf this season that has had this problem. They euthanized the other calf after she had not improved over 2 to 3 days. The calves are very valuable, and the producer would like to keep this calf in the herd. Further questioning of the owner reveals an increased percentage of abortions this year, she also bought several new replacement cows last fall that have been introduced to the here.Clinical Examination. The calf has a normal temperature, pulse, and respiration. She appears responsive to noise, almost hyperexcitable. There is no evidence of trauma. When the calf is placed in a standing position, she sways back and forth; she tries to maintain a base-wide stance but sometimes falls over or backs up. She appears extremely uncoordinated and hypermetric. She scores a 4/5 on ataxia, with 5 being the most severe. Otherabnormalities include a greatly delayed menace response; it is difficult to tell it her vision is within normal limits because she is bumping into things when she tries to walk. When she is laid back down and her reflexes are assessed, the calf is hyperreflexic in all her responses.
Comment. Based on this history of the herd and the calf, this herd most likely has a problem with bovine viral diarrhea virus (BVDV). This was likely introduced by replacement cows. BVDV would explain the abortions as well as the two affected calves. With BVDV, the virus infects the germinal cells within the cerebellum and also kills the Purkinje cells. Infection of these cells results in local inflammation, cell death, hemorrhage, and necrosis. Because of the damage to the Purkinje cells, inhibitory function is disrupted, which affects the vestibulocerebellum, spinocerebellum, and cerebro- cerebellum. The deficits in these areas are associated with clinical signs of abnormalities in balance (vestibulocerebellum), eye movement (vestibulocerebellum), ataxia and base-wide stances (vestibulo- and spinocerebellum), and motor coordination and sequencing (spino- and Cerebrocerebellum).
Treatment. Because BVDV causes irreversible cell damage, the prognosis for this calf is poor. Even if treatment were available, the calf most likely has BVDV and would shed virus if reintroduced into the herd. Euthanasia is the best option for this calf. The owner should screen the herd and identify infected and persistently infected (PI) animals. Additionally, vaccination with a live versus a killed BVDV vaccine may improve overall outcome.