Although lambing season is winding down, the MSU VDL would like to alert practitioners to some recent small ruminant abortion cases in the state. Recently the laboratory has received specimens from cases of sheep and goat abortions that were positive for Coxiella burnetti, the agent that causes Q fever in humans.
Organisms are shed at parturition and in the milk and feces. Abortions tend to occur late in gestation, and weak lambs and kids may be born during an outbreak. The aborted fetus may be well preserved or autolyzed, and although histologic lesions may be seen in both the placenta and fetus, gross lesions are limited to the placenta. Grossly the placenta may be thickened and/or "leathery" with areas of mineralization. Specimens (fetus and placenta) may be submitted to the VDL as a necropsy abortion (Code 30022). Currently, the MSU VDL performs Coxiella testing only as part of a necropsy abortion.
From Producer Disease Awareness on U.S. Sheep Operations, 2011 (USDA APHIS Veterinary Services Info Sheet, June 2015):
Q fever is an infection caused by the intracellular gram-negative bacterium Coxiella burnetii, found worldwide (except in New Zealand). Also called coxiellosis, the bacteria can infect a wide range of hosts, but the primary reservoirs are sheep, goats, and cattle. The disease is not generally considered problematic in animals, but it can cause abortion storms in sheep and goats and also poses a public health risk as it is zoonotic. When asked, the majority of sheep producers had never heard of Q fever or had heard of the name only (82.8 percent).
More information about Q fever in humans can be found on the CDC Web site: http://www.cdc.gov/qfever/index.html