CLINCAL AND PATHOLOGICAL
DIAGNOSIS OF INTERSTITIAL
PNEUMONIA IN CATTLE
Alfonso Lopez
Dept. Pathology and Microbiology
Atlantic Veterinary College
University of Prince Edward Island
Canada
Prince Edward Island
Atlantic Veterinary College
University of Prince Edward Island
1984
CLASSIFICATION OF PNEUMONIA
IN DOMESTIC ANIMALS
One of the most controversial topics in Veterinary
Medicine
• There is no Universal Classification:
• Epidemiologic: Enzootic pneumonia, Contagious,. Progressive, etc.
• Morphologic Features: Gangrenous, proliferative, exudative, etc.
• Etiology: Bacterial pneumonia, viral pneumonia, aspiration pneumonia, etc.
• Miscellaneous Criteria: Atypical, Cuffing Pneumonia, calf pneumonia,
• BRD Complex (acute undifferentiated bovine respiratory disease
In Veterinary Pathology the most popular classifications is
based on morphologic features
Texture
Distribution
Gross appearance
exudate
MORPHOLOGIC TYPES OF PNEUMONIA
Bronchopneumonia
– Ex. Mannheimia haemolytica
Embolic Pneumonia
– Ex. Hepatic abscess, endocarditis
Granulomatous Pneumonia
– Ex. Tuberculosis
Interstitial Pneumonia
Interstitial Pneumonia
• Clinical Practice
– Textbooks
– Clinical History
+++
+/-
• Diagnostic Laboratories
– Interstitial pneumonia
+++
– Bronchointerstitial pneumonia ++
Historically
• Interstitial Pneumonia (virus)
• Atypical Interstitial Pneumonia
– Fog Fever (Tryptophan / 3-MI)
– Extrinsic Allergic Alveolitis
– Reinfection Syndromes (Dictyocaulus
spp or BRSV)
– Others…
Interstitial Pneumonia
• Most difficult type to diagnose in a
postmortem examination:
– Non- collapsible lung
– Fills the thoracic cavity
– Costal imprints
– Elastic or meaty texture
– Diffuse distribution
• The type of pneumonia in which is
most difficult to reach etiological
diagnosis
– Virology
– Toxicology
– CLINICAL HISTORY
Objectives:
To investigate the CLINICAL and PATHOLOGICAL
criteria to diagnose Interstitial Pneumonia in cattle
RETROSPECTIVE
STUDY
AVC Diagnostic Laboratory
Electronic data files
INTERSTITIAL PNEUMONIA IN CATTLE
Selection Criteria:
Diagnostic Criteria:
• Final Diagnosis
• Alveolar thickening
• At necropsy
• Necrotizing bronchiolitis
• Clinical History
• Diffuse alveolar damage
• Hyaline Membranes
1998-2007
• Virology-Bacteriology
INTERSTITIAL PNEUMONIA IN CATTLE
RESULTS
Data base (1998-2007):
INTERSTITIAL PNEUMONIA IN CATTLE
Diagnostic Criteria
Histopathology
Diagnostic Criteria
• Postmortem Diagnosis
• H&E slides
• Alveolar thickening
• Histological diagnosis
• Special Stains
• Necrotizing bronchiolitis
• Immunohistochemistry §
• Diffuse alveolar damage
• Hyaline Membranes
• Virology-Bacteriology
RESULTS
RESULTS
Necrotizing Bronchiolitis
Virus Identification
27.7%
7.7 %
Atypical Interstitial Pneumonia
Sepsis
Plus Bronchopneumonia
15.5%
55.3%
32.2%
CONCLUSIONS
• Interstitial Pneumonia is rarely suspected by clinicians
• Interstitial pneumonia is the most difficult type of pneumonia to diagnose
during a postmortem examination
• It has the lowest success rate for etiological diagnosis
• Most commonly associated to viral infections (IBR, BRSV, PI-3). Why?
• Acute Respiratory Distress Syndrome (ARDS) should be suspected when
there is microscopic evidence of diffuse alveolar damage and hyaline
membranes in alveoli
• Sepsis, particularly in young calves, is often associated but not suspected
with Interstitial Pneumonia
THANKS FOR YOUR
ATTENTION