JPC SYSTEMIC PATHOLOGY

RESPIRATORY SYSTEM

October 2017

P-V22 (NP)

 

Signalment (JPC# 1737276):  Dairy cows, breed unspecified

HISTORY:  A number of dairy cows from a herd in the Republic of South Africa were reluctant to move and walked with a stiff gait.  Several cows developed severe respiratory signs and died in a matter of hours. Tissue presented is from one of the dead cows.

HISTOPATHOLOGIC DESCRIPTION:  Lung:  There are multifocal to coalescing areas of alveolar edema affecting approximately 60% of the section; the edema is admixed with variable amounts of fibrin, low numbers of sloughed pneumocytes, hemorrhage, neutrophils, macrophages, and lymphocytes .  Multifocally, alveolar septa are thickened up to 3 times normal by edema, variable amounts of fibrin, few neutrophils, lymphocytes, and macrophages.  Adjacent peribronchial and peribronchiolar connective tissue is mildly expanded by a similar inflammatory infiltrate.  There is diffuse marked interstitial emphysema with compression of adjacent alveoli and multifocal mild paraseptal emphysema. The tunica media and adventitia of several blood vessels is infiltrated by low numbers of lymphocytes, neutrophils, and macrophages with increased clear space of perivascular connective tissue and ectatic lymphatics (edema).  Multifocally the lumina of bronchi and bronchioles contain an exudate composed of moderate numbers of degenerate neutrophils, streaming leukocyte nuclei, sloughed epithelial cells, and necrotic cellular debris. These inflammatory cells multifocally extend into the adjacent peribronchial connective tissue.   

MORPHOLOGIC DIAGNOSIS:  Lung:  Pneumonia, bronchointerstitial, subacute, multifocal, moderate, with diffuse marked interstitial emphysema, breed unspecified, bovine.

ETIOLOGIC DIAGNOSIS:  Rhabdoviral pneumonia

CAUSE:  Bovine ephemeral fever virus

CONDITION:  Bovine ephemeral fever (BEF)

SYNONYMS:  Three-day sickness, bovine epizootic fever, three-day stiff sickness, dragon boat disease

GENERAL DISCUSSION:

PATHOGENESIS:

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS: 

TYPICAL LIGHT MICROSCOPIC FINDINGS:

ULTRASTRUCTURAL FINDINGS: 

ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS:

COMPARATIVE PATHOLOGY:

References:

  1. Bowen RA. Rhabdoviridae. In: MacLachlan NJ, Dubovi EJ, eds. Fenner’s Veterinary Virology. London, UK: Elsevier Inc; 2011:338-9.
  2. Hamblin C. Bovine ephemeral fever. In: Foreign Animal Diseases. 7th ed. Boca Raton, FL: United States Animal Health Association;2008: 175-83.
  3. Robinson WF, Robinson NA. Cardiovascular system. In: Maxie ME, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. 6th ed. Vol 3. Philadelphia, PA: Elsevier; 2016:79-80.

 

 


Click the slide to view.



Click on image for diagnostic series.



Back | Home | Contact Us | Links | Help |