Specific and Contagious Diseases. 149 
recent years is the susceptibility of dogs to diphtheria. 
The cause is ascertained to rest with the defective state 
of the drainage, the gases from which are inhaled, or by 
the access of putrilage to the system, the medium being 
the food. By nature the dog is surprisingly immune as 
to many putrid forms of disease, as he is almost the only 
scavenger in many countries; yet it appears to be possible 
for the system to become susceptible as the animal is 
exposed to the operation of causes while under con- 
‘strained or domestic conditions. My late friend Professor 
Robertson, in his extended observations was enabled to 
witness the effects of the disease in a number of horses, 
as well as a kennel of greyhounds, and I give the results 
of his experience in the following observations. 
Some of the cases were characterised by high fever at 
the outset, when the inflammation was acute, the mouth, 
fauces, tonsils and palate being of a dark red colour, 
tense, smooth, and glistening, as a result of distension 
from sub-cellular infiltration. The gland structures were 
swollen and tender, which rendered. swallowing difficult 
‘or impossible. The early signs were increase of temper- 
ature, accelerated pulse and respiration, and when this 
increased functional activity subsided, the animal was 
depressed, and listless from a want of muscular energy. 
The end of the disease was betokened by emesis, 
diarrhoea and death. In those surviving twenty-four 
hours were the characteristic grey coagulable exudate, 
sometimes arranged in spots or stripes, but always 
adherent to the mucous membrane; more frequently 
the exudation was glossy, tenacious, soft, and devoid of 
structural arrangement, or granular material was thickly 
deposited in some parts, or almost absent in others. 
In another form there was less fever, and the power of 
swallowing was only slight. 
In the third form the disease was principally located in 
the nasal passages, being characterised by dulness, and 
fever of a low type, with sore throat, sanious discharge 
from the nostrils, and a similar. fluid, mingled with saliva, 
flowed over the tongue when the mouth was examined. 
