Abstract
A raccoon dog (Nyctereutes procyonoides; Family: Canidae), was given cardiac muscle of reindeer infected with S. grueneri, and started shedding Sarcocystis sporocysts 10 days post feeding. The sporocysts measured 13.9 (12.4–15.7) × 10.1 (9.2–11.2) µm, and were excreted for at least 16 days. The raccoon dog is thus an additional definitive host for S. grueneri (Yakimoff & Sokoloff, 1934) Gjerde, 1984. Another raccoon dog was given skeletal muscle infected with 4 species of Sarcocystis, none of which was S. grueneri. The raccoon dog started shedding Sarcocystis sporocysts on day 10 post feeding, and excreted sporocysts for at least 16 days. The sporocysts measured 14.0 (12.3–15.6) × 10.1 (9.2–11.2) µm, and are considered to be sporocysts of S. tarandivulpes Gjerde, 1984. This is the first record of the raccoon dog as an experimental definitive host for Sarcocystis.