October 2017



Signalment (JPC #1492980):  3-month-old cat

HISTORY:  Section of lung from a cat killed two days after aerosol infection with an experimental agent.

 HISTOPATHOLOGIC DESCRIPTION:  Lung:  There is consolidation and atelectasis affecting approximately 70% of the lung.  Within areas of consolidation, alveolar septa are fragmented, discontinuous and replaced by fibrin and eosinophilic cellular and karyorrhectic debris (septal necrosis), lined by hyperplastic cuboidal epithelium (type II pneumocyte hyperplasia) or expanded up to 8 times normal by fibrin, edema, neutrophils and macrophages.  Alveolar, and to a lesser extent bronchiolar and bronchial lumina are filled with variable amounts of fibrin, edema, hemorrhage, eosinophilic cellular and karyorrhectic debris (necrosis), neutrophils and alveolar macrophages.  There is bronchiolar epithelial hyperplasia.  Multifocally, blood vessels are lined by plump endothelial cells (reactive endothelium).  There is perivascular edema and hemorrhage and the pleura is mildly thickened by fibrin and hemorrhage.

MORPHOLOGIC DIAGNOSIS:  Lung:  Pneumonia, interstitial, necrotizing, focally extensive, marked, with type II pneumocyte hyperplasia, breed unspecified, feline.

ETIOLOGIC DIAGNOSIS:  Caliciviral pneumonia

CAUSE:  Feline calicivirus (FCV)









Feline respiratory diseases:



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  6. Pesavento PA, MacLachlan NJ, Dillard-Telm L, Grant CK, Hurley KF. Pathologic, Immunohistochemical, and Electron Microscopic Findings in Naturally Occurring Virulent Systemic Feline Calicivirus Infection in Cats. Vet Pathol. 2004;41(3):257-263.
  7. Pesavento PA, Stokol T, Liu H, van der List DA, Gaffney PM, Parker JS. Distibution of the Feline Calicivirus Receptor Junctional Adhesion Molecule A in Feline Tissues. Vet Pathol. 2011;48(2):361-368.
  8. Stiles J. Ocular Infections. In: Greene CE, ed. Infectious Diseases of the Dog and Cat. 4th ed. St Louis, MO: Elsevier; 2012:1060-1063.
  9. Van Bonn WG. Pinnipdia, Disease. In: Fowler ME, Miller RE eds. Zoo and Wild Animal Medicine. 8nd ed. Philadelphia, PA: WB Saunders, Co. 2015:446.



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