JPC SYSTEMIC PATHOLOGY

RESPIRATORY SYSTEM

October 2017

P-V11

 

Signalment:  Adult Barnvelder hen, Gallus gallus, avian

HISTORY (JPC #4057682): Hens in a “backyard” flock developed respiratory distress following close contact with ducks overnight in a very small poorly ventilated accommodation.  The ducks and geese remain unaffected.  Clinical signs included anorexia, depression, mouth breathing, nasal discharge, coughing and gasping.

HISTOPATHOLOGIC DESCRIPTION:  Trachea:  The architecture of the tracheal mucosa and submucosa is diffusely irregular, eroded or ulcerated, with epithelium lost and replaced by an extensive inflammatory infiltrate composed of large numbers of lymphocytes and macrophages admixed with fewer plasma cells, heterophils, fibrin and hemorrhage. The inflammatory infiltrate occasionally extends into the underlying adventitia and adjacent parenchyma. Within the mucosa, respiratory epithelial cells fuse and contain up to thirteen nuclei (viral syncytial cells).  Viral syncytial cell nuclei often contain a single round eosinophilic intranuclear viral inclusion body that is 3-6 um in diameter, surrounded by a clear halo, and peripheralizes the chromatin.  Overlying the mucosa is an exudate composed of eosinophilic cellular and karryorhectic debris (necrosis) admixed with hemorrhage, eosinophilic fibrillar material (fibrin), previously described inflammatory cells, viral syncytial cells, and small colonies of cocci (diphtheritic membrane).

MORPHOLOGIC DIAGNOSIS:  Trachea:  Tracheitis, acute, fibrinous and necrotizing, severe, with epithelial viral syncytial cells and intranuclear viral inclusion bodies, chicken, Barnvelder, avian.

ETIOLOGIC DIAGNOSIS: Alphaherpesviral tracheitis

CAUSE:  Avian infectious laryngotracheitis virus (Gallid herpesvirus type 1)

CONDITION:  Infectious Laryngotracheitis; Fowl Diphtheria

GENERAL DISCUSSION:

PATHOGENESIS:

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS:

TYPICAL LIGHT MICROSCOPIC FINDINGS:

 ULTRASTRUCTURAL FINDINGS:

 ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS:

COMPARATIVE PATHOLOGY:

Other affected galliformes include: Indian peafowl, guineafowl, pheasants and turkeys

Other Herpesviral Respiratory Diseases:           

REFERENCES:

  1. Garcia, M, Spatz S, Guy JS. Infectious laryngotracheitis. In: Swayne DE, ed. Diseases of Poultry. 13th ed. Ames, IA: Wiley-Blackwell Publishing; 2013:161-179.
  2. Hamer SA, Amuzie CJ, Williams KJ, Smedley RC. Pathology in practice: infectious laryngotracheitis in laying chickens. J Am Vet Med Assoc. 2013;242(4):477-9.
  3. Humberd J, Maricarmen G, Riblet SM, Resurreccion RS, Brown TP. Detection of infectious laryngotracheitis virus in formalin-fixed, paraffin-embedded tissues by nested polymerase chain reaction. Avian Diseases. 2002;46:64-74.
  4. Ojkic D, Brash ML, Jackwood MW, Shivaprasad HL. Viral diseases.  In: Boulianne M, ed.  Avian Disease Manual. 7th ed.  Jacksonville, FL: American Association of Avian Pathologists, Inc; 2013:59-61.
  5. Osterrieder K. Herpesvirales. In: MacLachlan NJ, Dubovi EJ, eds. Fenner’s Veterinary Virology. 5th Ed. London, UK: Elsevier Inc; 2017:195-6.
  6. Sary K, Chénier S, Gagnon CA, et al. Esophagitis and pharyngitis associated with avian infectious laryngotracheitis in backyard chickens: two cases.  Avian Dis. 2017;61(2):255-260.

 

                                                                                                                                   

 


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