460 
Foot-and-Mouth Disease. 
have the effect of retarding the expulsion of the poison, and 
leading to a diseased state of the blood and the fluids derived 
from it. 
Animals under these circumstances become emaciated, the 
abrasions of the buccal membrane advance to the condition of 
ulcers, the hoofs become loosened by exudation from the vascular 
membrane of the internal foot, abscess forms in the areolar 
membrane under the skin ; skin wounds caused by the animal 
lying down much assume an unhealthy character, and large 
portions of the tissue are sloughed away, and the beast ultimately 
succumbs to a state which may correctly be termed putrid, 
otherwise it is destroyed as useless owing to the hopeless con- 
dition of the feet, and the general prostration. 
Foot-and-mouth disease is sometimes complicated with more 
malignant diseases ; as splenic apoplexy, apoplectic congestion 
of lungs, and other forms of blood disease ; the fatality which 
attends these complications cannot properly be referred to the 
foot-and-mouth complaint, as the maladies themselves are ex- 
ceedingly fatal, and it is probable that their virulent nature is 
not materially modified by the existence of the milder affection 
in conjunction with them. 
An attack of foot-and-mouth disease does not protect the 
animal from any other disease, but it has usually been held that 
a recovered animal was safe from a return of the same affection ; 
and there is evidence that a certain amount of protection is 
afforded against a second attack, although the system is not 
rendered absolutely secure for any length of time. 
Instances of animals being affected with foot-and-mouth com- 
plaint twice in the space of a few months were of occasional 
occurrence in the early periods of the disease, and a third attack 
was not unknown. Recently, second and third attacks at short 
intervals among cattle have been more numerous, or at least more 
have been recorded ; whether the cases have really been more 
frequent than in former years, or our attention has been more 
closely attracted to them, is not quite clear. Veterinary autho- 
rities in Switzerland however state, quite as a matter of course, 
that the susceptibility of the animal's system to the action of 
the virus is not only not exhausted, but is in no way lessened 
or otherwise modified by an attack of the disease. 
Our experience in this country justifies the statement, that 
under ordinary circumstances, animals which have recovered 
from foot-and-mouth disease are not liable to the affection again, 
at a period so early as to excite attention ; but it is also true 
that during the prevalence of the affection in an epizootic form, 
the liability to infection is indefinitely increased, and at the same 
time the amount of active contxujiwni is also increased. In other 
