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Parainfluenza
virus-3 is extremely widespread in cattle and 80-90% have antibody. Pathogenesis and
clinical signs: Isolates vary in virulence. Cessation of ciliary beating and
epithelial necrosis predispose to secondary bacterial infections and coughing.
Calf pneumonia is a complex respiratory disease probably associated as much with
management (crowding, low ventilation, high humidity, colostral deprivation, transport
stress, mixing of stock from differing herds). The agents are : PI-3, bovine respiratory
syncytial virus, infectious bovine rhinotracheitis virus, Mycoplasmata and Pasteurellae.
Shipping fever occurs in beef cattle after long journeys. |