50 CANINE DISTEMPER 
no infectious disease exists, or has recently existed, in 
either establishment would probably assist materially, 
though that is open to some doubt. 
Risks Attending Dogs “on Approval.’—A similar ob- 
jection attaches to the practice of sending dogs on trial 
or approval, for they have been frequently observed to’ 
fall ill soon after their return home. As previously 
stated, a dog usually acquires immunity after his initial 
attack. In other cases, where a puppy grows up in a 
contaminated environment, it frequently becomes immune 
to the predominating infection of its own kennel without 
exhibiting at any time more than the most transient 
indisposition ; but expose this same dog to a new strain 
of contagion and it readily falls a prey, or will in turn 
(although considered quite healthy) transmit a virulent 
attack to strange dogs. 
- The only precautionary measure practicable is rigidly 
to isolate the brood bitch immediately upon her return 
from stud, and for the owner of the sire, after departure 
of the bitch, to do likewise for at least two weeks. Dogs 
returning from “approval” should be similarly treated 
as suspects before allowing them to mix again with the 
other inmates of the kennel. Although this would not 
avoid the incidence of disease in the animals concerned, 
it would at least prevent an outbreak of serious dimen- 
sions throughout the whole establishment; entailing, 
most probably, considerable loss of time and great in- 
convenience, yet in the end it would prove a very much 
cheaper and wiser policy. 
Public Highways.—A constant source of infection are 
the public highways, parks, etc., where dogs of all 
breeds are perpetually exposed to both mediate and 
immediate contagion. If a dog is to be allowed its 
freedom to run in the streets there would seem to be no 
way of protecting it except by the somewhat uncertain 
