Sarcocystis in muscles of raccoons (Procyon lotor L.)

Sarcocysts of Sarcocystis sp. were found in 26 (50%) of 52 raccoons (Procyon lotor) from Ohio, Pennsylvania, Florida, and Maryland. Although only 4 (7.7%) of 52 cardiac muscles specimens were found to contain sarcocysts, 25% to 36.5% of tongue, diaphragm, masseter muscle, and esophagus specimens were found infected. By light microscopy, sarcocyst walls were less than 3 micron thick and had no conspicuous projections; interior septa were indistinct. By transmission electron microscopy, sarcocyst walls had short (mean = 2.7 micron), villus-like protrusions; thin septa were seen within the sarcocysts. The raccoon may be an intermediate host for a Sarcocystis sp. that completes its life cycle in an unidentified, wild carnivore.