Encephalomyelitis Associated With A Sarcocystis-Like Protozoan in A Ten-Month-Old Ewe Lamb
This paper reports the pathological findings of non-suppurative encephalomyelitis associated with a Sarcocystis-like protozoan in a 10-month-old ewe lamb showing neurological signs. The encephalomyelitis was characterized by mild to moderate multifocal perivascular mononuclear cell infiltrations, and randomly scattered glial foci, especially more severe in the thalamus, cerebellum, and pons. A few protozoan meronts were observed within the endothelium of small capillaries in the thalamus, and small numbers of mature tissue cysts, similar to muscle sarcocysts, in sections of the cerebrum and pons. All muscle samples of this lamb had also a severe mixed infection with sarcocysts of S. tenella and S. arieticanis.
Encephalomyelitis Associated With A Sarcocystis-Like Protozoan in A Ten-Month-Old Ewe Lamb
This paper reports the pathological findings of non-suppurative encephalomyelitis associated with a Sarcocystis-like protozoan in a 10-month-old ewe lamb showing neurological signs. The encephalomyelitis was characterized by mild to moderate multifocal perivascular mononuclear cell infiltrations, and randomly scattered glial foci, especially more severe in the thalamus, cerebellum, and pons. A few protozoan meronts were observed within the endothelium of small capillaries in the thalamus, and small numbers of mature tissue cysts, similar to muscle sarcocysts, in sections of the cerebrum and pons. All muscle samples of this lamb had also a severe mixed infection with sarcocysts of S. tenella and S. arieticanis.
___
- Dubey, J.P.: A review of Sarcocystis of domestic animals and of other Coccidia of cats and dogs. J. Am. Vet. Med. Assoc., 1976; 169: 1061-1078. 2. Dubey, J.P., Speer, C.A., Fayer, R.: Sarcocystosis of Animals and Man. CRC Press, Inc., Boca Raton, Florida, 1989; 113-120. 3. Stubbings, D.P., Jeffrey, M.: Presumptive protozoan (Sarcocystis) encephalomyelitis with paresis in lambs. Vet. Rec., 1985; 116: 373-374.
- Fitzgerald, S.D., Janovitz, E.B., Kazacos, K.R., Dubey, J.P., Murphy, D.A.: Sarcocystosis with involvement of the central nervous system in lambs. J. Vet. Diagn. Invest., 1993; 5: 291- 296. 5. Caldow, G.L., Gidlow, J.R., Schock, A.: Clinical, pathological and epidemiological findings in three outbreaks of ovine protozoan myeloencephalitis. Vet. Rec., 2000; 146: 7-10.
- Sargison, N.D., Schock, A., Maclean, I.A., Rae, A, Heckeroth, A.R., Clark, A.M.: Unusual outbreak of sporozoan encephalomyelitis in Bluefaced Leicester ram lambs. Vet. Rec., 2000; 146: 225-226. 7. Henderson, J.M., Dies, K.H., Haines, D.M., Higgs, G.W., Ayroud, M.: Neurological symptoms associated with sarcocystosis in adult sheep. Can. Vet. J., 1997; 38: 168-170. 8. O’Toole, D., Duffell, S.J., Upcott, D.H., Frewin, D.: Experimental microcyst Sarcocystis infection in lambs: Pathology. Vet. Rec., 1986; 119: 525-531.
- O’Toole, D., Jeffrey, M., Challoner, D., Maybey, R., Welch, V.: Ovine myeloencephalitis-leukomyelomalacia associated with a Sarcocystis-like protozoan. J. Vet. Diagn. Invest., 1993; 5: 212- 225.
- Jeffrey, M., O’Toole, D., Smith, T., Bridges, A.W.: Immunocytochemistry of ovine sporozoan encephalitis and encephalomyelitis. J. Comp. Pathol., 1988; 98: 213-224.
- McAllister, M.M., McGuire, A.M., Jolley, W.R., Lindsay, D.S., Trees, A.J., Stobart, R.H.: Experimental neosporosis in pregnant ewes and their offspring. Vet. Pathol., 1996; 33 : 647-655.
- Luna, L.G.: Manual of Histologic Staining Methods of the Armed Forces Institute of Pathology. 3rd ed, McGraw-Hill Book Company, New York, Toronto, London, Sydney, 1968; 38-39.
- Erber, M.: Möglichkeiten des Nachweisses und der Differenzierung von Zwei Sarcocystis-Arten des Schweines. Berl. Münch. Tierarztl. Wochenschr. 1977; 90: 480-482.
- Scott, P.R., Watt, N.J., Woodman, M.P., McGorum, B., McDiarmid, A.: Protozoan encephalomyelitis causing pelvic limb paresis in a yearling sheep. New Zeal. Vet. J., 1993; 41: 139- 141.
- Parihar, N.S.: Sarcocystis in sheep brain. Indian J. Anim. Sci., 1987; 57: 1291-1293.