CLINCAL AND PATHOLOGICAL DIAGNOSIS OF INTERSTITIAL

PNEUMONIA IN CATTLE

Alfonso Lopez

Dept. Pathology and MicrobiologyAtlantic Veterinary College

University of Prince Edward IslandCanada

Prince Edward Island

Atlantic Veterinary CollegeUniversity of Prince Edward Island

19841984

• 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 featuresTexture Distribution

Gross appearance exudate

Embolic Pneumonia– Ex. Hepatic abscess, endocarditis

Bronchopneumonia– Ex. Mannheimia haemolytica

MORPHOLOGIC TYPES OF PNEUMONIAGranulomatous 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

AVC Diagnostic LaboratoryElectronic data files

Selection Criteria:

• Final Diagnosis

• At necropsy

• Clinical History

RETROSPECTIVESTUDY INTERSTITIAL PNEUMONIA IN CATTLE

1998-2007

Diagnostic Criteria:

• Alveolar thickening

• Necrotizing bronchiolitis

• Diffuse alveolar damage

• Hyaline Membranes

• Virology-Bacteriology

INTERSTITIAL PNEUMONIA IN CATTLE

RESULTS

Data base (1998-2007):

INTERSTITIAL PNEUMONIA IN CATTLEINTERSTITIAL 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

RESULTS

RESULTSRESULTS

CONCLUSIONSCONCLUSIONS

• 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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