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Bovine respiratory disease
Bovine respiratory disease or BRD is the most common disease amongst feedlot cattle. It can also be difficult to detect in its early stages. The initial signs to look for are cattle that are showing depression and lethargy. Cattle that are showing one or more of the signs of breathing difficulty, lethargy and oral and/or nasal discharge could be in the early stages of BRD and should be removed from the pen and examined.
The single most important factor to treatment success is to find those cattle early in the disease course. Look for those animals that that are showing a lack of interest in their surroundings, moving with a reduced purpose, beginning to carry their heads lower than normal, have slightly sunken eyes or looking tired or sleepy.
Advanced BRD
Once cattle begin to drag their feet and carry their heads low they are most likely in a more advanced phase of the disease and successful treatment is more difficult. Where an animal’s immune system is unable to cope with the normal stresses and challenges found in the feedlot environment it can develop BRD. Once the normal bacteria that reside in the nose and throat extend down into the lungs and lower respiratory tract they multiply and destroy the lung tissue. When these bacteria get into the blood stream and move around the body an animal will exhibit the signs of increased respiration rate and severe depression and begin to relinquish normal prey animal behaviour, such as trying to hide amongst other animals and fleeing when a human approaches. If BRD cases are missed during the early stages when treatment is still a viable option they can become unsalvageable and need to be culled.