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 hstless 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 miaterial 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. 



