UNITED STATES DEPARTMENT OF AGRICULTURE 
Contribution from the Bureau of Animal Industry 
JOHN R. MOHLER, Chief. 
Washington, D. C. PROFESSIONAL PAPER April 28, 1919 
OAK-LEAF POISONING OF DOMESTIC ANIMALS. 
By C. Dwicut Mars, Physiologist in Charge of Poisonous-Plant Investigations, A. B. 
Ciawson, Physiologist, and HapiercH Marsu, Veterinary Inspector, Bureau of 
Animal Industry. 
CONTENTS. 
Page. Page. 
Historicalsummary and review ofliteraturc.. 1 | General results of experimental work—Con- 
Poisoning by oak leaves in North America... 6 tinued. : 
Experimental work with scrub oak.......... 7 Active principle or principles causing 
Experimental work with ‘‘shinnery”’ oak... 21 oak-brush poisoning......-.....-.-.-- 33 
General results of the experimental work ..-. 30 | Summary of conclusions from experimental 
Sieatip laisse eas ese eB CR Sas Zsic 30 WODKe eer sels choi 2h NON Ma a Panes ease 
TST UCTOS i 6 1 ae ee ee 31 | Discussion of results with relation to previous 
Microscopic pathology........-.-...-.-- 32 IMyesticahlousey ose seee eee ae ee oO 
Length of time necessary to produce Practical considerations forrange grazing... .. 35 
harm from oak brush....-.......-.---- 32 | Literature cited........_.- EOL we eceon see 36 
Effect of eating oak with other feeds ..-- 33 
HISTORICAL SUMMARY AND REVIEW OF LITERATURE. 
Although the literature on poisoning by acorns is extensive, publi- 
cations on poisoning by oak leaves are comparatively few. The. 
earliest recorded statement regarding the injurious properties of oak 
leaves is by Mascal, 1662, page 243,' who says ‘‘ Again oak leaves, if 
sheep eat thereof green, it is evil for them, especially for young lambs, 
which will kill them; and likewise of other cattel.”’ 
Apparently there was no other reference to this subject until 1893, 
when Cornevin treats of it quite fully. As this is the only extended 
account in the literature and as his work is not common in hbraries, 
his statement is quoted in full (by translation) as follows: 
There are no less than 300 species of the genus Quercus. For our purpose we con- 
sider only one, the most common. Moreover what is said about this will apply to the 
others, 
Quercus robur, L. (Chéne rouvre).—According to many botanists we should unite 
under this Linnean species the two varieties Q. pedunculata Thrh. and Q. sessiflora 
Smith as well as the forms derived from them, especially Q. Cerris and (. pubescens 
Wills. 
1 For complete titles of works cited see list of literature on page 36. 
99620°-—-19—Bull. 767——1 
