UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 767 
Contribution from the Bureau of Animal Industry 
JOHN R. MOHLER, Chief 
Washington, D. C. PROFESSIONAL PAPER April 28, im 
OAK-LEAF POISONING OF DOMESTIC 
ANIMALS 
By 
G. DWIGHT MARSH, Physiologist in Charge of Poisonous Plant 
Investigations, A. B. CLAWSON, Physiologist, and 
HADLEIGH MARSH, Veterinary Inspector, 
Bureau of Animal Industry 
CONTENTS 
Page 
Historical Summary and Review of Literature ........ I 
Poisoning by Oak Leaves in North America 6 
Experimental Work With Scrub Oak . . . 7 
Experimental Work With "Shinnery" Oak 21 
General Results of the Experimental Work 30 
Symptoms 30 
Autopsy Findings 31 
Microscopic Pathology 32 
Length of Time Necessary t© Produce Harm From Oak Feeding . . 32 
. Effect of eating oak with other feeds 33 
Active Principle or Principles Causing Oak-Brush Poisoning ... 33 
Summary of Conclusions From Experimental Work 34 
Discussion of Results With Relation to Previous Investigations . . . 35 
Practical Considerations for Range Grazing 35 
Literature Cited 36 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1919 
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