Sarcocystis encephalomyelitis in sheep

Josepha DeLayAnimal Health Laboratory, University of

Guelph

History200+ ewe flock

acute onset neurologic signs confined to 1 pen of

8 month old lambs

17 / 40 affected over a 10 day period2 / 17 dead (1 necropsied), 4 additional

affected lambs euthanized and necropsied

Clinical findingsClinical signs:

DepressedAnorexicBlindHead / body tremors, weakness, hindlimb

ataxia

Differential diagnoses: polioencephalomalacia, listeriosis

Initial therapy: thiamine, tetracycline – no response

bar 50 um

bar 10 um

Brain (medulla oblongata), lamb C

Brain (midbrain), lamb B

Sarcocystis spp IHC (cerebellum)

Skeletal muscle, lamb B

Myocardium, lamb C

Sarcocystis spp IHC (myocardium)

from M.Jeffrey, 1993, In Practice, 15: 2-8.

Additional historyNew guardian dogs purchased ~2 months

prior to onset of neurologic disease in flock

Dogs were acclimatized to sheep by housing in sheep barn, with access to feed bunk area of pen housing affected sheep

Outcome:3 treatment groups based on pathology

diagnosisAmproliumToltrazurilNo treatment

Improvement in mental status and appetite regardless of

treatmentNo additional sick lambs or deaths in 2 months

following initial outbreak

Thank you to OVC collaborators on this case:

Dr. Andrew PeregrineDr. Paula MenziesDr. Jonathan HuskaDr. Luis Gaitero