Bovine Respiratory Disease (BRD)

BRD: bovine respiratory disease is stress-related common respiratory diseases worldwide that produces signs of severe bronchopneumonia in all ages, particularly young calves.

BP: bronchopneumonia: inflammation of the bronchioles and lung alveoli associated with severe coughing, nasal discharge, fever anorexia and dyspnea.

Dyspnea: is the difficulty of respiration due to inflammation of respiratory tract, congestion f the lining mucosa and narrowing of the lumen. It is manifested as oral breathing or panting (open mouth).

Anorexia: complete loss of appetite manifested by stopping of rumination and ruminal stasis

Fever: increased temp of the animal above the normal limit which is 37.8-39.2 C in ruminant. Fever is manifested as red mucous membranes, dullness, depression.

Stress: any deviation from the optimum condition of animal where a stimulus, internal or external, chemical, physical, emotional, managemental or behavioral stimulates the neurons of the hypothalamus to produce corticotrophin-releasing hormone (ACTH).

Stressors: Factors that stimulate homeostatic, physiological, and behavioral responses in excess of normal (exaggerated response). It could include shipping, transportation, climate change, stocking, dehorning, weaning, and malnutrition.

DART system:  include evaluation of the affected calves for the presence of depression (D), anorexia (A), respiratory character change (R), increased rectal temperature (T).