JPC SYSTEMIC PATHOLOGY

RESPIRATORY SYSTEM

October 2017

P-V09

 

Signalment (AFIP #1947253) (Slide A)3-week-old kitten, breed and sex unspecified

HISTORY:  One of three kittens that died within 24 hours of exhibiting open mouth breathing and lethargy

HISTOPATHOLOGIC DESCRIPTION: 

Lung:  Over 90% of bronchial, bronchiolar and alveolar epithelium is replaced by eosinophilic cellular and basophilic karyorrhectic debris (lytic necrosis).  There is marked septal necrosis with replacement and thickening of alveolar septa by fibrin, necrotic debris, hemorrhage, edema and increased numbers of macrophages and lymphocytes. The basement membranes surrounding smooth muscle and connective tissue of bronchioles and bronchi are multifocally lost, replaced by necrosis and fibrin and expanded by edema and small amounts of hemorrhage. Rare epithelial cells and macrophages contain round, eosinophilic, 4-7 um, intranuclear viral inclusion bodies that marginate the chromatin. The interstitium surrounding bronchi, bronchioles and vessels is expanded by fibrin, edema, hemorrhage and necrotic debris which contains moderate numbers of neutrophils and macrophages.  Alveolar lumina, and to a lesser extent bronchi and bronchiolar lumina contain varying amounts of: fibrin, edema, degenerate neutrophils, necrotic debris, sloughed epithelial cells, few macrophages. The pleura is mildly expanded by fibrin, edema, necrotic debris, degenerate neutrophils and few macrophages.

Liver:  There are multifocal, pinpoint, less than 90um diameter, random foci of hepatocellular lytic necrosis characterized by cells with condensed, hypereosinophilic cytoplasm and pyknotic to karyolytic nuclei.  Hepatocytes adjacent affected areas are degenerate and rarely contain round, eosinophilic, 4-7 um, intranuclear viral inclusion bodies that marginate the chromatin.

MORPHOLOGIC DIAGNOSES:  1. Lung:  Pneumonia, bronchointerstitial, fibrinonecrotic, acute, diffuse, with rare epithelial and histiocytic eosinophilic intranuclear viral inclusion bodies, breed unspecified, feline.

  1. Liver: Hepatitis, necrotizing, acute, multifocal and random, with eosinophilic intranuclear viral inclusion bodies.

Signalment (AFIP #963777) (Slide B)A kitten, breed and sex unspecified 

HISTORY:  Died showing signs of respiratory distress

HISTOPATHOLOGIC DESCRIPTION:  Nasal turbinates and sinuses:  Multifocally, there is attenuation, erosion, and ulceration of ciliated nasal epithelium and goblet cells with replacement by necrotic cellular debris, fibrin, hemorrhage, and numerous degenerate and transmigrating neutrophils.  Adjacent degenerate epithelial cells are occasionally swollen with abundant clear cytoplasm and nuclei which contain round, eosinophilic, 4-7um, intranuclear viral inclusion bodies that marginate the chromatin.  Many neutrophils with fewer macrophages and lymphocytes surround nasal glands and expand the submucosa, and vessels in affected areas are lined by reactive endothelium.  Multifocally, sinuses contain an exudate composed of many neutrophils admixed with sloughed epithelial cells and fibrin. 

MORPHOLOGIC DIAGNOSIS:  Nasal turbinates and sinuses:  Rhinitis and sinusitis, necrotizing and suppurative, subacute, multifocal, moderate, with eosinophilic intranuclear viral inclusion bodies, breed unspecified, feline.

ETIOLOGIC DIAGNOSIS:  Feline herpesviral pneumonia, hepatitis, rhinitis, and sinusitis

CAUSE:  Felid herpesvirus-1 (FHV-1)

CONDITION:  Feline viral rhinotracheitis (FVR)

GENERAL DISCUSSION:

PATHOGENESIS:

 TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS:

TYPICAL LIGHT MICROSCOPIC FINDINGS:

 ULTRASTRUCTURAL FINDINGS:

ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS:

Rhinitis and conjunctivitis:

Pneumonia:

Skin lesions (ulcerative dermatitis): 

COMPARATIVE PATHOLOGY: 

Other alpha-herpesviruses:

 REFERENCES:

  1. Caswell JL, Williams KJ. Respiratory system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol. 2, 6th ed. St. Louis, MO: Elsevier; 2016:588-589.
  2. Hargis, AM, Myers S. The Integument. In: Zachary JF ed. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Elsevier; 2017:1069, 1142-1143.
  3. Labelle P. The Eye. In: Zachary JF ed. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Elsevier; 2017: 1316
  4. Zachary JF. Mechanisms of microbial infections. In: Zachary JF ed. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Elsevier; 2017: 212.
  5. Pesavento PA, Murphy BG. Common and Emerging Infectious Diseases in the Animal Shelter. Vet Pathol. 2014;51(2):478-491.
  6. Rodriguez JMM, Leeming G, Kohler K, Kipar A. Feline herpesvirus pneumonia: investigations into the pathogenesis. Vet Pathol. On-line-first, electronic publication https://doi.org/10.1177/0300985817720982 2017.

 

 


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