AIP in the Feedlot

AIP in the Feedlot AIP is the acronym for Acute (or Atypical) Interstitial Pneumonia. This disease is known by various different names over the years, such as Acute Bovine Pulmonary Emphysema and Edema, Bovine Asthma, Feedlot Dust Pneumonia, Fog Fever and the list goes on.     It is a primary respiratory disease that leads to severe edema and emphysema of the lung tissue that leads to death in the majority of cases. This is documented to be the second most important respiratory disease affecting feedlot cattle. The financial impact of AIP can be significant, since it normally affects cattle in the finishing stage of their feeding period, animals which by that time increased in value to the producer due to increased weight – the result of various costly inputs. Outside the feedlot setting, AIP is reported (often as outbreaks) on lush green pastures and fermented crops. Especially when moving animals from low quality roughage, to high quality pasture that have high protein levels. With a sudden increase in protein levels, L-Tryptophan (a common amino acid/or protein building block) is converted to 3-Methylindole (3-MI) in the rumen by bacterial species such Lactobacillus. 3-MI is then readily absorbed through the rumen into the bloodstream, and when it reaches the lungs it gets converted to 3-Methyleneindolenine (3-ME) and this molecule is then responsible for causing the damage to the lungs seen in AIP.  The above description is accepted as the etiology for Fog Fever. In the feedlot setting however, there are no […]