The placenta shed from goats with classical scrapie is infectious to goat 
kids and lambs
 
David A. Schneider, D.V.M., Ph.D. (das@vetmed.wsu.edu)1, Sally A. 
Madsen-Bouterse, Ph.D.2, Dongyue Zhuang3, Thomas C. Truscott4, Rohana P. 
Dassanayake, Ph.D.5 and Katherine I. O'Rourke, Ph.D.6 
 
+ Author Affiliations 1 Animal Disease Research Unit, Agricultural Research 
Service, U.S. Department of Agriculture 2 Department of Veterinary Microbiology 
and Pathology, College of Veterinary Medicine, Washington State University 3 
Animal Disease Research Unit, Agricultural Research Service, U.S. Department of 
Agriculture 4 Animal Disease Research Unit, Agricultural Research Service, U.S. 
Department of Agriculture 5 Department of Veterinary Microbiology and Pathology, 
College of Veterinary Medicine, Washington State University 6 Department of 
Veterinary Microbiology and Pathology, College of Veterinary Medicine, 
Washington State University Received 5 March 2015. Revised 9 April 2015. 
Accepted 14 April 2015. 
 
Abstract
 
The placenta of domestic sheep plays a key role in horizontal transmission 
of classical scrapie. Domestic goats are frequently raised with sheep and are 
susceptible to classical scrapie, yet potential routes of transmission from 
goats to sheep are not fully defined. Sparse accumulation of disease-associated 
prion protein in cotyledons casts doubt about the role of the goat's placenta. 
Thus, relevant to mixed-herd management and scrapie-eradication efforts 
worldwide, we determined if the goat's placenta contains prions orally 
infectious to goat kids and lambs. A pooled cotyledon homogenate, prepared from 
the shed placenta of a goat with naturally acquired classical scrapie disease, 
was used to orally inoculate scrapie-naïve prion genotype-matched goat kids and 
scrapie-susceptible lambs raised separately in a scrapie-free environment. 
Transmission was detected in all four goats and in two of four sheep which 
importantly identifies the goat's placenta as a risk for horizontal transmission 
to sheep and other goats. 
 
snip... 
 
In conclusion, this study importantly demonstrates that the placenta of 
goats infected with classical scrapie can transmit scrapie to susceptible goat 
kids and lambs via a natural route of exposure despite relatively sparse 
accumulation of PrPSc 179 within the goat’s placenta. Thus, like for sheep, the 
parturient materials and postpartum period of goats must be considered 
transmission risks for other susceptible small ruminants and environmental 
contamination. 
 
 
Sunday, August 25, 2013 
 
Prion2013 Chronic Wasting Disease CWD risk factors, humans, domestic cats, 
blood, and mother to offspring transmission 
 
 
>>> Here, in an experimental model of CWD, we have demonstrated 
the transmission of infectious prions from clinical and subclinical mothers to 
full-term viable, nonviable and in utero harvested offspring, revealing that the 
transmission of TSEs from mother to offspring can occur and may be 
underestimated for all prion diseases. <<< 
 
Tuesday, September 17, 2013 
 
Mother to Offspring Transmission of Transmissible Spongiform Encephalopathy 
TSE prion disease 
 
 
Wednesday, April 22, 2015 
 
Circulation of prions within dust on a scrapie affected farm 
 
 
 
TSS