Acta Neuropathologica

, Volume 76, Issue 1, pp 46–54 | Cite as

Canine protozoan polyradiculoneuritis

  • J. F. Cummings
  • A. de Lahunta
  • M. M. Suter
  • R. H. Jacobson
Regular Papers


Four pups in a litter of eight Labrador Retrievers suddenly developed hind limb weakness. In three, paralysis ascended rapidly resulting in quadriplegia, cervical weakness, dysphagia and death. Postmortem examination revealed a severe polyradiculoneuritis in which roots, ganglia, and spinal and cranial nerves were heavily infiltrated by lymphocytes, plasma cells and macrophages and contained abundant protozoan pseudocysts. On sections of the brain and spinal cord protozoa were less frequent and appeared independent of the glial nodules which marked focal areas of necrosis. The organisms innitially were thought to beToxoplasma gondii, but this supposition was not supported by serological, immunocytochemical, or electron microscopic findings. Ultrastructurally the organisms resembled an unidentified sporozoan parasite, which has been reported in the CNS of dogs in Scandinavia. The inflamed spinal roots contained many degenerated and demyelinated axons. Electron microscopic studies indicated that the tachyzoite-like organisms, through their invasive and proliferative activities, brough about many of the degenerative changes in the Schwann cells and axons of the spinal roots and nerves.

Key words

Polyradiculoneuritis Protozoa Schwann cell destruction Axon degeneration Dog 


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  1. 1.
    Averill DR, de Lahunta A (1971) Toxoplasmosis of the canine nervous system: clinicopathologic findings in four cases. J Am Vet Med Assoc 159:1134–1141Google Scholar
  2. 2.
    Bjerkås I, Mohn SF, Presthus J (1984) Unidentified cystforming sporozoon causing encephalomyelitis and myositis in dogs. Z Parasitenkd 70:271–274Google Scholar
  3. 3.
    Bjerkås I, Landsverk T (1986) Identification ofToxoplasma gondii andEncephalitozoon cuniculi by immunoperoxidase techniques and electron microscopy in stored formalin-fixed paraffin-embedded tissue. Acta Vet Scand 27:11–22Google Scholar
  4. 4.
    Core DM, Hoff EJ, Milton JL (1982) Hindlimb hyperextension extension as a result ofToxoplasma gondii polyradiculitis. J Am Animal Hosp Assoc 19:713–716Google Scholar
  5. 5.
    Cummings JF, Haas DC (1967) Coonhound paralysis. An acute idiopathic polyradiculoneuritis in dogs resembling Landry-Guilain-Barré syndrome. J Neurol Sci 4:51–81Google Scholar
  6. 6.
    Drake JC, Hime JM (1967) Two syndromes in young dogs caused byToxoplasma gondii. J Small Anim Pract 8:621–626Google Scholar
  7. 7.
    Dubey JP (1986) Toxoplasmosis in dogs: a review. Canine Pract 12:7–28Google Scholar
  8. 8.
    Duncan ID, Griffiths IR (1984) Peripheral neuropathies of domestic animals. In: Dyck PJ, Thomas PK, Lambert EH, Bunge R (eds) Peripheral neuropathy, 2nd edn, vol 1. Saunders, Philadelphia, pp 718–719Google Scholar
  9. 9.
    Ehrensperger F, Suter M (1977) Radiculitis toxoplasmica beim Hund. Kleintier Praxis 22:59–62Google Scholar
  10. 10.
    Ghatak NR, Sawyer DR (1978) A morphological study of opportunistic cerebral Toxoplasmosis. Acta Neuropathol (Berl) 42:217–221Google Scholar
  11. 11.
    Griffin JW, Hoffman PN, Clark AW, Carroll PT, Price DL (1978) Slow axonal transport of neurofilament proteins: impairment byβ,β′-iminodiproprionitrile administration. Science 202:633–635Google Scholar
  12. 12.
    Hilali M, Lindberg R, Walter T, Wallin B (1986) Enigmatic cyst-forming sporozoon in the spinal cord of a dog. Acta Vet Scand 27:623–625Google Scholar
  13. 13.
    Jones TC, Hirsch JG (1972) The interaction betweenToxoplasma gondii and mammalian cells. II. The absence of lysosomal fusion with phagocytic vacuoles containing living parasites. J Exp Med 136:1173–1194Google Scholar
  14. 14.
    Nesbit JW, Lourens DC, Williams MC (1981) Spastic paresis in two littermate pups caused byToxoplasma gondii. J S Afr Vet Assoc 52:243–246Google Scholar
  15. 15.
    Northington JW, Brown MJ, Farnbach GC, Steinberg SA (1981) Acute idiopathic polyneuropathy in the dog. J Am Vet Med Assoc 179:375–379Google Scholar
  16. 16.
    Scholtyseck E (1979) Fine structure of parasitic protozoa. An atlas of micrographs, drawings and diagrams. Springer, Berlin Heidelberg New YorkGoogle Scholar
  17. 17.
    Scholtyseck E, Mehlhorn H, Müller BEG (1973) Identifikation von Merozoiten der vier cystenbildenden Coccidien (Sarcocystis, Toxoplasma, Besnoitia, Frenkelia) auf Grund feinstruktureller Kriterien. Z Parasitenkd 42:185–206Google Scholar
  18. 18.
    Sheffield HS, Melton ML (1968) The fine structure and reproduction ofToxoplasma gondii. J Parasitol 54:209–226Google Scholar
  19. 19.
    Sulzer AJ, Scholtyseck E, Callaway C, Smith MT, Huber TW (1979) Diagnosis of Toxoplasmosis by electron microscopic fine-structural analysis. Am J Clin Pathol 72:225–229Google Scholar
  20. 20.
    Suter MM, Hauser B, Palmer DG, Otelli P (1984) Polymyositis-polyradiculitis due to Toxoplasmosis in the dog: serology and tissue biopsy as diagnostic aids. Zentralbl Veterinärmed [A] 31:792–798Google Scholar

Copyright information

© Springer-Verlag 1988

Authors and Affiliations

  • J. F. Cummings
    • 1
    • 2
  • A. de Lahunta
    • 1
    • 2
  • M. M. Suter
    • 1
    • 2
  • R. H. Jacobson
    • 1
    • 2
  1. 1.Departments of Anatomy and Pathology, New York State College of Veterinary MedicineCornell UniversityIthacaUSA
  2. 2.The Diagnostic Laboratory, New York State College of Veterinary MedicineCornell UniversityIthacaUSA

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