Bilateral pelvic limb paresis developed in 7 of 15 10-month-old Blueface Leicester ram lambs on a mixed enterprise farm in the North of England. Clinical signs were principally mild to severe paresis of the pelvic limbs. Two mildly affected lambs recovered. Multifocal spinal cord white matter edema and necrosis, glial nodules, and mild to moderate nonsuppurative encephalomyelitis were the principal findings in 3 severely paretic lambs examined histologically. Protozoan bodies (12.7–23.0 μm) that stained immunocytochemically for Sarcocystis epitopes were in spinal cord glial cells of 2 of 3 lambs. Protozoa did not react immunocytochemically with anti-Toxoplasma gondii or Neospora canium antisera. Serology indicated there was recent exposure to Sarcocystis spp. in some surviving lambs. These cases resembled those in previous reports of paresis due to an unidentified Sarcocystis-like protozoan in sheep (ovine protozoan myeloencephalitis) in the British Isles, the USA, France, Australia, and New Zealand.
References
1.
BarrBCConradPADubeyJP: 1991, Neospora-like encephalomyelitis in a calf: Pathology, ultrastructure, and immunoreactivity. J Vet Diagn Invest3: 39–46.
2.
BoxEDSmithJH: 1982, The intermediate host spectrum of a Sarcocystis sp. in birds. J Parasitol68: 668–673.
CarriganM J: 1986, An outbreak of sarcocystosis in dairy cattle. Aust Vet J63: 22–24.
5.
ColleryPWeaversE: 1981, An outbreak of sarcocystosis in calves in Ireland. Ir Vet J35: 159–162.
6.
DubeyJPBeattieCP: 1988, Toxoplasmosis of animals and man, pp. 70, 165. CRC Press, Boca Raton, FL.
7.
DubeyJPDavisSWSpeerCA: 1991, Sarcocystis neurona n.sp. (Protozoa; Apicomplexa), the etiologic agent of equine protozoal myeloencephalitis. J Parasitol77: 212–218.
8.
DubeyJPHartleyWJBadmanRT: 1989, Fatal perinatal sarcocystosis in a lamb. J Parasitol75: 980–982.
9.
DubeyJPHartleyWJLindsayDS: 1990, Fatal congenital Neospora caninum infection in a lamb. J Parasitol76: 127–130.
10.
DubeyJPLindsayDS: 1990, Neospora caninum induced abortion in sheep. J Vet Diagn Invest2: 230–233.
11.
DubeyJPSpeerCAFayerR: 1989, Sarcocystosis of animals and man, pp. 62–70, 113–120. CRC Press, Boca Raton, FL.
12.
DubeyJPSpeerCAMundayBL: 1989, Ovine sporozoan encephalomyelitis linked to Sarcocystis infection. Vet Parasitol34: 159–163.
13.
DubeyJPTowleA: 1986, Toxoplasmosis in sheep: A review and annotated bibliography, pp. 30–32. Commonwealth Institute of Parasitology, St. Albans, England.
14.
DuncanJRPrasseKW: 1986, Veterinary laboratory medicine: Clinical pathology, 2nd ed., p. 229. Iowa State University Press, Ames, IA.
15.
ErberM: 1982, Life cycle of Sarcocystis tenella in sheep and dog. Z Parasitenkd68: 171–180.
16.
ErberMBurgkartM: 1981, Wirtschaftliche Verluste durch Sarkosporidiose (Sarcocystis ovicanis und S. spec) bei der Mast von Schaflammem. Prakt Arzt62: 422–427.
17.
FordGE: 1985, Immunity of sheep to homologous challenge with dog borne Sarcocystis species following varying levels of prior exposure. Int J Parasitol15: 629–634.
18.
FordGE: 1986, Role of the dog, fox, cat and human as carnivore vectors in the transmission of the sarcosporidia that affect sheep meat production. Aust J Agric Res37: 79–88.
19.
FrelierPFLewisRM: 1984, Hematologic and coagulation abnormalities in acute bovine sarcocystosis. Am J Vet Res45: 40–48.
20.
FrelierPMayhewIGFayerR: 1977, Sarcocystosis: A clinical outbreak in dairy calves. Science195: 1341–1342.
21.
GilesRCTramontinRKadelWL: 1980, Sarcocystosis in cattle in Kentucky. J Am Ve, Med Assoc176: 543–548.
22.
HeydoinAO: 1985, Zur Entwicklung von Sarcocystis arieticanis n. sp.Berl Munch Tierarztl Wochenschr98: 231–241.
23.
HeydomAOKaraerZ: 1986, Zur schizogonie von Sarcocystis ovicanis. Berl Munch Tierarztl Wochenschr99: 185–189.
24.
JeffreyMLowJCUgglaA: 1989, A myopathy of sheep associated with Sarcocystis infection and monensin administration. Vet Rec124: 422–426.
25.
JeffreyMO'TooleDSmithT: 1988, Immunocytochemistry of ovine sporozoan encephalitis and encephalomyelitis. J Comp Pathol98: 214–224.
26.
LeekRGFayerR: 1978, Sheep experimentally infected with Sarcocystis from dogs. Cornell Vet68: 108–123.
27.
LeekRGFayerR: 1980, Amprolium for prophylaxis of ovine Sarcocystis. J Parasitol66: 100–106.
28.
LeekRGFayerR: 1983, Experimental Sarcocystis ovicanis infection in lambs: Salinomycin chemoprophylaxis and protective immunity. J Parasitol69: 271–276.
29.
LeekRGFaverRJohnsonAJ: 1977, Sheep experimentally infected with Sarcocystis from dogs. 1. Disease in young lambs. J Parasitol63: 642–650.
30.
LevineND: 1986, The taxonomy of Sarcocystis (Protozoa, Apicomplexa) species. J Parasitol72: 372–382.
31.
MeadsEB: 1976, Dalmeny disease-another outbreak-probably sarcocystosis. Can Vet J17: 271.
32.
Ministry of Agriculture, Fisheries and Food: 1984, Manual of veterinary investigation. 3rd ed., vol. 1, pp. 22, 87–88, 127, 185. Her Majesty's Stationery Office, London, England.
33.
Ministry of Agriculture, Fisheries and Food: 1984, Manual of veterinary investigation, 3rd ed., vol. 2, pp. 26–29, 162–164, 173–175, 178–179. Her Majesty's Stationery Office, London, England.
34.
MundayBL: 1979, The effect of Sarcocystis ovicanis on growth rate and haematocrit in lambs. Vet Parasitol5: 129–135.
35.
MundayBLBarkerIKRickardMK: 1975, The developmental cycle of a species of Sarcocystis occurring in dogs and sheep with observations on pathogenicity in the intermediate host. Z Parasitenkd46: 111–123.
36.
NietfeldJCDubeyJPAndersonML: 1992, Neospora-like protozoan infection as a cause of abortion in dairy cattle. J Vet Diagn Invest4: 223–226.
37.
NolanAGoldringOLCatchpoleJ: 1987, Demonstration of antibodies to Eimeria species in lambs by an enzyme linked immunosorbent assay. Res Vet Sci42: 119–123.
38.
O'DonoghuePJFordGE: 1984, The asexual pre-cyst development of Sarcocystis tenella in experimentally infected specific pathogen-free lambs. Int J Parasitol14: 345–355.
39.
O'TooleDDuffellSJUpcottDH: 1986: Experimental microcyst Sarcocystis infection in lambs: Pathology. Vet Rec119: 525–531.
40.
SimpsonCFMayhewIG: 1980, Evidence for Sarcocystis as the etiologic agent of equine protozoal myeloencephalitis. J Protozool27: 288–292.
41.
SmithTSHerbertIV: 1986, Experimental microcyst Sarcocystis infection in lambs: Serology and immunohistochemistry. Vet Rec119: 547–550.
42.
SpeerCAWhitmanWMRedukerDW: 1986, In vitro cultivation of meronts of Sarcocystis cruzi. J Parasitol72: 677–683.
43.
StrichSJ: 1968, Notes on the Marchi method for staining degenerating myelin in the peripheral and central nervous system. J Neurol Neurosurg Psychiatry31: 110–114.
44.
StubbingsDPJeffreyM: 1985, Presumptive protozoan (Sarcocystis) encephalomyelitis with paresis in lambs. Vet Rec116: 373–374.
