CHAPTER XXII 
TOXICOLOGY 
It is a well established fact that considerable variations in toler- 
ance to drugs of a toxic nature exist in animals of different species. 
While these variations have been pointed out in the case of mam- 
malian species, little information is found in toxicologic literature 
on the toxicity to fowls of drugs or poisonous substances which may 
be of value in the treatment or control of avian diseases. 
The experiments described in this chapter were undertaken by 
Gallagher for the purpose of determining the toxic doses for 
fowls of the more commonly used medicinal agents and of poisonous 
substances to which fowls not infrequently have access. No attempt 
was made to fix the toxic dose in certain instances where the sub- 
stance on test proved non-toxic when given in comparatively large 
quantities. A few tests only were made with each substance. The 
results of these are summarized in the doses indicated under the name 
of each drug. In a few instances reference has been made to obser- 
vations by other writers. 
In each experiment, unless otherwise stated, fluids were admin- 
istered directly into the esophagus or crop by means of a pipette and 
solids were given in gelatin capsules per os. 
Medium sized healthy mature hens weighing between 3 and 4 
pounds were usually employed. Those of larger size are designated. 
All doses were given while the crop contained a normal amount of 
food. 
From the results of the experiments it may be concluded that in 
general fowls may be considered as having approximately the same 
susceptibility to toxic substances as medium sized dogs. They are 
more resistant than dogs to such substances as calomel, strvchnine 
and tartar emetic, and less resistant to carbolic acid, salicylic acid 
and potassium cyanide. 
In treating outbreaks of disease in fowls, it is of great advantage 
to employ the drinking water as a vehicle for medicinal agents. It 
is shown that fowls are not visibly affected by drinking solutions of 
bichloride of mercury 1-6000, carbolic acid 1-1000, permanganate 
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