JPC SYSTEMIC PATHOLOGY

NERVOUS SYSTEM

February 2017

N-V20

 

Signalment, Slide A (JPC #2389731):  1 1/2-year-old male cockatoo

HISTORY:  The bird was lethargic and anorexic for some time.  It seemed to be wasting away and had been regurgitating food off and on for several weeks.  Grossly, the proventriculus and ventriculus were dilated.

HISTOPATHOLOGIC DESCRIPTION:

  1. Small intestine and mesentery: Multifocally there is an infiltrate composed of moderate numbers of lymphocytes and plasma cells that centers on the myenteric plexuses and extends into the adjacent tunica muscularis.  Within affected myenteric ganglia, there are decreased numbers of ganglion cells.  Similar inflammatory cells are also present within nerve bundles of the adjacent mesentery.  There is diffuse mesenteric fat atrophy with reduced adipocyte cytoplasm containing one or more varisized intracytoplasmic lipid vacuoles, prominence of nuclei, and blood vessels in close proximity to one another.
  2. Cerebrum: Multifocally there are perivascular infiltrates of low numbers of lymphocytes and plasma cells within the gray and white matter and the leptomeninges.
  3. Peripheral nerve: Multifocally within the nerve and surrounding epineurium, there are perivascular aggregates of lymphocytes and plasma cells.

MORPHOLOGIC DIAGNOSIS:

  1. Small intestine and mesentery: Ganglioneuritis and leiomyositis, lymphoplasmacytic, subacute, multifocal, mild, with ganglion cell loss, cockatoo, avian.
  2. Cerebrum: Meningoencephalitis, lymphoplasmacytic, subacute, multifocal, mild.
  3. Peripheral nerve: Epineuritis, lymphoplasmacytic, subacute, multifocal, mild.
  4. Adipose tissue, mesentery: Fat atrophy, diffuse, moderate.
  5. Kidney: No significant findings.

Signalment, Slide B (JPC #2820183):  Female psittacine

HISTORY:  Chronic weight loss

HISTOPATHOLOGIC DESCRIPTION:

  1. Heart: Diffusely, nerves subjacent to the epicardium contain an infiltrate of low numbers of lymphocytes and plasma cells that occasionally extend into the surrounding connective tissue.
  2. Liver: Multifocally within portal areas, there is an infiltrate composed of low numbers of lymphocytes and plasma cells, and rare heterophils.

MORPHOLOGIC DIAGNOSIS:

  1. Heart, epicardial nerves: Neuritis, lymphoplasmacytic, subacute, diffuse, moderate.
  2. Liver: Hepatitis, portal, lymphoplasmacytic and heterophilic, subacute, multifocal, mild.

ETIOLOGIC DIAGNOSIS:  Bornaviral ganglioneuritis, leiomyositis, meningoencephalitis, neuritis, and hepatitis

CAUSE:  Avian bornavirus (ABV)

CONDITION:  Proventricular dilatation disease (PDD)

CONDITION SYNONYMS:  Psittacine proventricular dilatation syndrome (PDDS), neuropathic gastric dilatation (NGD), macaw wasting disease, lymphoplasmacytic ganglioneuritis and encephalomyelitis

GENERAL DISCUSSION:

PATHOGENESIS:

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS:

TYPICAL LIGHT MICROSCOPIC FINDINGS:

ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS:

For gross finding of proventricular dilation:

For lymphoplasmacytic meningoencephalitis in birds:

Intestinal poxvirus infection and Pacheco’s disease can lead to proventricular lesions grossly and histologically similar to PPD

COMPARATIVE PATHOLOGY:

REFERENCES:

  1. Caines D, Pinard CL, et al. Autonomic dysfunction in a Jack Russell terrier. Can Vet J. 2011; 52:297-299.
  2. Cantile C, Youssef S. Nervous system.  Maxie MG ed. In: Jubb Kennedy and Palmer's Pathology of Domestic Animals. Vol 1. 6th ed. Philadelphia, PA:  Elsevier Saunders; 2016:377-378..
  3. Collette SA, McManamon R, Rech RR, Howerth EW. Pathology in practice. Proventricular dilatation disease. J Am Vet Med Assoc. 2010;236(5):519-521.
  4. De Kloet SR, Dorrestein GM. Presence of avian bornavirus RNA and anti-avian bornavirus antibodies in apparently healthy macaws. Avian Dis. 2009;53(4):568-573.
  5. Donatti RV, Resende M, et al. Fatal proventricular disease in captive native psittacines in Brazil. Avian Dis. 2014; 58(1):187-193.
  6. Gray P, Hoppes S, Suchodolski P, et al. Use of avian bornavirus isolates to induce proventricular dilatation disease in conures. Emerg Infect Dis. 2010;16(3):473-479.
  7. Guo J, Tizard I, Baroch J, et al. Avian bornaviruses in North American gulls. J Wildl Dis. 2015; 51(3):754-758.
  8. Honkavuori KS, Shivaprasad HL, Williams BL, et al. Novel borna virus in psittacine birds with proventricular dilatation disease. Emerg Infect Dis. 2008;14(12):1883-1886.
  9. Hoppes S, Gray PL, Payne S, Shivaprasad HL, Tizard I. The isolation, pathogenesis, diagnosis, transmission, and control of avian bornavirus and proventricular dilatation disease. Vet Clin North Am Exot Anim Pract. 2010;13(3):495-508.
  10. Keller DL, Honkavuori KS, Briese T. Proventricular dilatation disease associated with avian bornavirus in a scarlet macaw (Ara macao). J Vet Diagn Invest. 2010;22(6):961-965.
  11. Kistler AL, Smith JM, Greninger AL, Derisi JL, Ganem D. Analysis of naturally occurring avian bornavirus infection and transmission during an outbreak of proventricular dilatation disease among captive psittacine birds. J Virol. 2010;84(4):2176-2179.
  12. Raghav R, Taylor M, Delay J, et al. Avian bornavirus is present in many tissues of psittacine birds with histopathologic evidence of proventricular dilatation disease. J Vet Diagn Invest. 2010;22(4):495-508.
  13. Rinder M, Ackermann A, Kempf H, Kaspers B, Korbel R, Staeheli P. Broad tissue and cell tropism of avian bornavirus in parrots with proventricular dilatation disease. J Virol. 2009;83(11):5401-5407.
  14. Rossi G, Crosta L, Pesaro S. Parrot proventricular dilation disease. Vet Rec. 2008;163(10):310.
  15. Schmidt RE, Reavill DR, Phalen DN. Gastrointestinal system and pancreas. In: Pathology of Pet and Aviary 2nd ed. Ames, IA: Wiley Blackwell; 2015:69-70.
  16. Shivapradsad HL. Miscellaneous diseases. In: Boulianne M, ed. Avian Disease Manual. 7th Jacksonville, FL: AAAP; 2013:199.
  17. Swayne DE, Barnes JH, Abdul-Aziz T, Fletcher OJ. Nervous system. In: Avian Histopathology. 4th Jacksonville, FL: AAAP; 2016:476,510

 

 

 


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