DISEASES. 597 



at once assume a rapid evolution of disorganization. We have 

 noticed this principally after the use of sharp instruments. 



Generally, animals affected with canker feed well, and for a 

 long time retain a good condition ; toward the end, however, they 

 lose flesh and exhibit symptoms of sejjticohemia, especially if 

 affected with grease. We do not admit that, as advanced by 

 some, canker can give rise to such virulent diseases as glanders 

 and farcy. 



Diagnosis. — At the beginning, canker may be confounded 

 with thrushes, and many veterinarians have considered this as the 

 first stage of canker. There is, however, a great difference be- 

 tween the two : first, as to the anatomo-pathological point of 

 view, inasmuch as the pultaceous, foetid secretion is less abund- 

 ant ; that the loosening of the hoof is less, and that there are no 

 fici; and again, especially in the point of view of the treatment, 

 where single cases of cleansing, with or without dessicatives, 

 easily control it, while canker remains rebellious to them. 



Prognosis. — The prognosis varies. Where the animal is 

 young, well fed, and the disease is not too old, it is favorable. 

 Yet it remains uncertain, as often the most benign form may last 

 long and remain rebellious to all treatment. The severity and the 

 extent of the internal lesions cannot be estimated by the altera- 

 tions or deformities of the hoof, as these appearances are often 

 deceptive. Canker, though considered incurable for a long time, 

 is not absolutely so — far from it ; with rational treatment, prop- 

 erly carried on, it is curable in the majority of cases. There are 

 cases, however, not very rare, where relapses and useless attempts 

 have discouraged the owner ^s well as the veterinarian, and where 

 it has been more advantageous to destroy the animal rather than 

 to submit him to a long, tiresome, and always expensive treat- 

 ment. 



Pathological Anatomy and Nature of the Disease. — It has 

 always been considered that a morbid condition susceptible of 

 producing disorders so severe as those produced by canker, must 

 necessarily be a deep affection, essential and important to the 

 organic structure, and depending on a complete transformation in 

 its texture. And, indeed, it is the impression which predominated 

 from the time of SoUeysel down to the foundation of veterinary 

 schools and which still exists with Girard, who considers canker 

 as a gnawing ulcer which changes and alters the tissues it invades, 



