16 FOREWORD 
on dogs depends on the amount of hydrochloric acid in 
the digestive tract. 
"When worms or their eggs are found in the stools 
vermifuges are used, and with some animals especially 
liable to infestation by intestinal worms, periodic doses of 
vermifuges are given as a prophylactic. Turpentine is 
given to the zebra at fixed intervals for the round worm ; 
santonin, male fern and areca nut to the carnivora for the 
various worms that are so common in the intestinal tracts 
of these animals. 
The work of the Laboratory of Pathology is throwing 
light on the subject of diagnosis, and though from the 
character of the clinical material diagnosis can never be 
as satisfactory as in the human, yet we may fairly hope 
for improvement. Prophylaxis is our chief reliance, and 
always will be. 
