Sarcocystis (Sarcocystis spp.)

MJ Pybus Fish & Wildlife Alberta SRD Alberta Wildlife & Fish Pybus MJ in Alberta

Common Significance In the carnivore, the immature individuals break out of the cysts, enter cells of the name Sarcocysts are benign little critters intestine, and begin to reproduce. They that live in the muscles and intestines sarcosporidiosis, eventually develop into sporocysts that sarcocystosis, rice of various birds and mammals. They can re-enter the intestine and be passed grain disease cause concern only when hunters see out along with the faeces. Sporocysts are them, most often in the breast well adapted to survival in the muscles of wild ducks. They are NOT environment as they wait and wait for an infective to humans herbivore to eat them. Once eaten by the right species of herbivore, the sporocysts release a different kind of immature Scientific What? Where? How? stage into the herbivore’s intestine. These name There are many, many species of immature sarcocysts burrow into blood sarcocysts. Generally, these single-celled vessels, produce multiple generations of single-celled protozoans animals live as tiny microscopic new and different immature stages, of the genus individuals in muscle cells or intestinal eventually enter muscle fibres, and Sarcocystis cells of infected animals. Groups of finally develop into a resting cyst. Pretty sarcocysts, often referred to as cysts, complicated for a single-celled animal!! can occasionally be seen in muscles of birds or mammals as white areas about the size and shape of a piece of rice. Distribution in Alberta These show up particularly well in the Sarcocysts make ready use of various dark breast muscles of dabbling ducks. wild and domestic birds and mammals as habitat in Alberta. The most conspicuous cysts are found in dabbling ducks, Transmission Cycle particularly shovelers, mallards, and Sarcocysts are superbly adapted to make gadwall. Cysts also occur in almost all use of predator/prey relationships. The moose, deer, and elk as well as a wide needs of sarcocysts change during their range of rodents and furbearers but they different life stages as herbivores and are generally too small to see. Dr. Marht What’s carnivores provide alternating habitats. from the University of Alberta conducted In herbivores (e.g., ducks, moose), a survey of various big game species Bugging sarcocysts develop as visible cysts that throughout central Alberta, and found contain hundreds of immature individuals. 50% to 75% of the animals examined, Wild The cysts provide food, warmth, depending on species had these cysts. moisture, and nutrients, as well as These ubiquitous animals (the sarcocysts) Critters? protection from the immune system. are well distributed throughout the While inside the cyst, these critters are province and around the world. in a resting stage and will not develop Fact sheet #11: further until the cysts (and the duck or moose!) are eaten by a carnivore Sarcocystis (possibly a skunk or a wolf, respectively). Pub.No: Sarcocystis in Alberta I/170 (Sarcocystis spp.) ISSN: 1710-4327 ISBN Print: 0-7785-3582-7 Importance for Wildlife Public Significance ISBN Online: 0-7785-3583-5 Management Sarcocysts do not pose a human health risk. There is little or no evidence that sarcocysts Some heavily infected ducks may be needlessly harm the habitats in which they live. As a discarded because hunters are concerned natural component in most if not all about the aesthetics of serving or eating meat ecosystems, these species are well adapted to loaded with the cysts! Cysts in lightly infected living in harmony with other members of the birds or birds that are plucked rather than system. skinned are undoubtedly eaten by many hunters and their friends. In case you are still concerned, rest assured that the cysts are killed by freezing and cooking.

Prevention/Control Control of these tiny protozoans is neither necessary nor possible. Fish & Wildlife Alberta SRD

Summary Sarcocysts are extremely common residents throughout Alberta. They are completely benign and pose no particular concern. They just live here.

Additional Information Parasitic Diseases of Wild Mammals, Second Edition. Edited by William M. Samuel, Margo J. Pybus and A. Alan Kocan. 2001. Chapter 17 – Tissue-inhabiting Protozoans. Northwest Territories Resources Wildlife Economic Development: http:// www.nwtwildlife.rwed.gov.nt.ca/Publications/diseasepamphletweb/sarcocystosis.htm University of Northern British Columbia: http://www.unbc.ca/nlui/wildlife_diseases_bc/ classified_causative_agent.htm USGS National Wildlife Health Center: http://www.nwhc.usgs.gov/pub_metadata/field_manual/ field_manual.html

2004 For more information on wildlife diseases in Alberta: http://www3.gov.ab.ca/srd/fw/diseases/index.html