JPC SYSTEMIC PATHOLOGY
HEMOLYMPHATIC SYSTEM
April 2018
H-P06

SIGNALMENT (AFIP #2377154):  4-week-old red-fronted parakeet (Cyanoramphus novaezelandiae)

HISTORY:  This parakeet was one of five in a brood that died suddenly.  Both parents were healthy.

HISTOPATHOLOGIC DESCRIPTION:  Heart:  Multifocally affecting 40% of the myocardium are numerous individual or aggregated intrahistiocytic protozoal megaloschizonts which measure up to 500 um in diameter and expand the myocardium, elevate the epicardium and endocardium and separate and compress adjacent cardiac myocytes.  Megaloschizonts have a pale eosinophilic, faintly anisotropic, 15 to 40 um thick wall that is often surrounded by an amphophilic matrix; the center is filled by abundant basophilic to eosinophilic granular cytoplasm, numerous clear spaces (artifact) and many variably distinct 1 to 2 um diameter basophilic, oval merozoites.  Adjacent to the megaloschizonts, there is compression, degeneration, atrophy and loss of cardiac myocytes.  Multifocally, hemorrhage and few lymphocytes and heterophils surround the megaloschizonts.

MORPHOLOGIC DIAGNOSIS:  Heart, myocardium:  Protozoal megaloschizonts, intrahistiocytic, numerous, with minimal lymphocytic and heterophilic myocarditis, hemorrhage, and myocardial loss, red-fronted parakeet (Cyanoramphus novaezelandiae), avian.

ETIOLOGIC DIAGNOSIS:  Cardiac leucocytozoonosis

CAUSE:  Leucocytozoon sp.

GENERAL DISCUSSION:

PATHOGENESIS:

LIFE CYCLE:

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS: 

TYPICAL LIGHT MICROSCOPIC FINDINGS:

TYPICAL ULTRASTRUCTURAL FINDINGS:

ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS:

Intraerythrocytic gametocytes:

COMPARATIVE PATHOLOGY:

References:

  1. Bermudez AF. Miscellaneous and sporadic protozoal infections. In: Swayne DE, ed. Diseases of Poultry. 13th ed. Ames, IA: Blackwell Publishing; 2013:1185-1188.
  2. Donovan TA, Schrenzel M, Tucker TA, Pessier AP, Stalis IH. Hepatic hemorrhage, hemocoelom, and sudden death due to Haemoproteus infection in passerine birds: Eleven cases. J Vet Diagn Invest. 2008; 20:304-313.
  3. Fitz-Coy SH. Parasitic Disease. In: Boulianne M, ed. Avian Disease Manual. 7th ed. Jacksonville, FL: American Association of Avian Pathologists, Inc.; 2013:159,163.
  4. Gardiner CH, Fayer R, Dubey JP. Apicomplexa. In: Gardiner CH, Poynton SL, eds. An Atlas of Protozoan Parasites in Animal Tissues. 2nd ed. Washington, DC: Armed Forces Institute of Pathology; 1998:65-68, 73-76.
  5. Garvon JM, Mott JB, Jacobs SS, et al. Blood Parasites of Blue-winged Teal ( Anas discors ) from Two Migratory Corridors, in the Southern USA. J Wildl Dis. 2016 Jul;52(3):725-9.
  6. Lee DH, Jang JH, Kim BY, et al. Diagnosis of Leucocytozoon caulleryi infection in commercial broiler breeders in South Korea. Avian Dis. 2014;58(1):183-186.
  7. Schmidt RE, Reavill DR, Phalen DN. Pathology of Pet and Aviary Birds. Ames, IA: Iowa State Press; 2015: 39, 109, 135, 227.
  8. Valkiunas G. Avian malaria parasites and other Haemosporidia. Boca Raton, FL: CRC Press; 2000:36-45.


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