If the illness is complicated by bacteria, appropriate antibiotic selection can be made through consultation with your veterinarian and using culture and sensitivity tests performed on tissues collected at necropsy. Mass medication, antibiotics given on arrival to all cattle, is a management strategy that has gained acceptance and has been demonstrated to be effective and economical under certain conditions. The exact mechanism by which mass medication therapies work to improve health is not known. One explanation is that pathogenic bacteria that reside in the nose and throat area are eliminated or greatly reduced in numbers. This reduces the chances of calves becoming clinically ill with bacterial pneumonia.
Bacteria are the only agents that are impacted by mass medication.
The spread of viruses and viral infection will not be impacted. In outbreak situations when mass medication has been used and response to antibiotic therapy in sick cattle is poor, then a primary viral component is likely to be responsible. However, mass medication upon arrival resulted in higher cost of gain and poorer breakevens compared to individual treatment for respiratory disease. One of the most effective tools for diagnosis and treatment of BRD is the use of a rectal thermometer. Animals suspected of having BRD should have temperatures taken and be treated based on rectal temperature.