1. CLINCAL AND PATHOLOGICAL DIAGNOSIS OF INTERSTITIAL PNEUMONIA IN CATTLE Alfonso Lopez Dept. Pathology and Microbiology Atlantic Veterinary College University of Prince Edward Island Canada

2. Prince Edward Island

3. Atlantic Veterinary College University of Prince Edward Island1984

4. 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 CLASSIFICATION OF PNEUMONIA IN DOMESTIC ANIMALS One of the most controversial topics in Veterinary Medicine In Veterinary Pathology the most popular classifications is based on morphologic features TextureDistribution Gross appearanceexudate

5. Embolic Pneumonia –Ex. Hepatic abscess, endocarditis Bronchopneumonia – Ex. Mannheimia haemolytica MORPHOLOGIC TYPES OF PNEUMONIA Granulomatous Pneumonia –Ex. Tuberculosis Interstitial Pneumonia

6. 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…

7. 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

8. Objectives: To investigate the CLINICAL and PATHOLOGICAL criteria to diagnose Interstitial Pneumonia in cattle

9. AVC Diagnostic Laboratory Electronic data files Selection Criteria: Final Diagnosis At necropsy Clinical History RETROSPECTIVE STUDY INTERSTITIAL PNEUMONIA IN CATTLE 1998-2007 Diagnostic Criteria: Alveolar thickening Necrotizing bronchiolitis Diffuse alveolar damage Hyaline Membranes Virology-Bacteriology

10. INTERSTITIAL PNEUMONIA IN CATTLE RESULTS Data base (1998-2007):

11. INTERSTITIAL PNEUMONIA IN CATTLE Diagnostic Criteria Alveolar thickening Necrotizing bronchiolitis Diffuse alveolar damage Hyaline Membranes Virology-Bacteriology Histopathology H&E slides Special Stains Immunohistochemistry § Diagnostic Criteria Postmortem Diagnosis Histological diagnosis

12. RESULTS

14. 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

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