Transcript Atypical Interstitial Pneumonia

Atypical Interstitial
Pneumonia
Cade Moses, DVM
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.
Heat Stress or AIP?
This posture can be heart failure, heat stress, chronic pneumonia, or AIP
Necropsy exam is a must!!
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
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 Ltryptophan)
• The L-tryptophan metabolism in the rumen
releases 3-methylindole which is a lung toxin
• The syndrome in feedlot cattle is not well
understood
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 Ltryptophan to 3-MI
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
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
AIP cause definition
• “The disease is related to the
interplay of feed intake, feed
composition, sex and physiologic
maturity, and possible environmental
triggers”
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
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
Fog Fever?
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
AIP Diagnosis
•Clinical signs will give a pretty
good determination
•Necropsy all AIP deads to
confirm that they are not
being misdiagnosed and
mistreated
Call for help before this happens!