A typical I nterstitial P neumonia

1. Atypical Interstitial Pneumonia Cade Moses, DVM

2. What is AIP? • It is a cause for severe pulmonary symptoms that often end in death • It has a rapid onset • Cattle are often exhibit open mouth breathing and stretched neck with an expiratory grunt. • This is due to air being physically pushed out of lungs with abdominal press. Looks different than many typical pneumonias in which the effort is on the in-breath.

3. Heat Stress or AIP?

4. This posture can be heart failure, heat stress, chronic pneumonia, or AIP Necropsy exam is a must!!

5. Pathology • Inflammation and widening of the connective tissue of the lungs. • Widened septae • Usually not a lot of fibrin and adhesions • Failure of lungs to collapse easily • May see large trapped air pockets (bulla) as well as smaller gas bubbles in septae (emphysema) • Lungs are heavy and sometimes “wet” • The most affected areas are in the dorsal or higher portion of the lung • The lower lung may be consolidated (no air) due to secondary bacterial infection

8. What is the cause? • We don’t really know! • The syndrome in cows is well understood. • Cows are transitioned rapidly to a high protein diet (specifically high in the amino acid L-tryptophan) • The L-tryptophan metabolism in the rumen releases 3-methylindole which is a lung toxin • The syndrome in feedlot cattle is not well understood

9. AIP Syndrome in Cows • The syndrome is also called “fog fever” in reference to dead cattle found in the lush mountain valleys where the fog settled. (high protein grass) • Rumensin has a protective effect in cows possibly by reducing the number of Lactobacillus bacteria which convert L-tryptophan to 3-MI

10. AIP Syndrome in Feedlot Cattle • Many possible triggers theorized • BRSV virus • Dust inhalation • Bacterial infection (lung or liver) • Protein rich diet • MGA • Inhalation of fungus • GI upset or acidosis • Heat • Feed Change

11. AIP Syndrome in Feedlot Cattle • Cattle are usually affected later in the feeding period • Bigger economic loss for the producer • Heifers seem to be more affected • Heavier cattle seem to be more affected

12. AIP cause definition • “The disease is related to the interplay of feed intake, feed composition, sex and physiologic maturity, and possible environmental triggers”

13. Can it be Controlled? • At this point best bet is to control the risk factors (remember none of these are proven) • BRSV virus • Ensure cattle are properly vaccinated, if using a 2 dose product for BRSV, give the 2nd dose • Dust inhalation • Control dust with scaping/sprinking if possible • Bacterial infection (lung or liver) • Medicated feed for liver abscess • Protein rich diet • Protein usually not that high in finish rations

14. Can it be Controlled? • MGA • Ensure regular consumption. Theorized that heifers fluctuate intake during weather or ration changes • Inhalation of fungus • Avoid moldy feedstuffs and hay dust • GI upset or acidosis • Ration changes • Heat • Heat stress protocol. Keep a sharp eye during hot weather • Feed Change • Beware during times of changing rations and feedstuffs

15. Fog Fever?

16. Treatment Options • Mostly supportive • Give a short withdrawl antibiotic that has good coverage against lung pathogens • Treat with IV fluniximine for inflammation • Consider dexamethsone for inflammation • Some have tried furosemide in attempt to “dry out lungs” • Reduce stress as much as possible • Shade, comfortable pen (move slow), easy access to feed/water

17. AIP Diagnosis • Clinical signs will give a pretty good determination • Necropsy all AIP deads to confirm that they are not being misdiagnosed and mistreated

18. Call for help before this happens!