218 MR. DICK ON THE CAUSES AND PREVENTION 
matter; or, by the play and inflammation being 1 kept up, ulcera¬ 
tion extends, and the toes are cleft up almost to the canal above 
them. This canal is inflamed ; the mucous follicles with which it 
is lined are increased in their action, and pour out a large quan¬ 
tity of sebaceous-like matter, which spreads over the fore-part 
of the foot, and between the hoofs, and assists in accumulating 
the filth by its adhesive qualities. In other forms of the disease, 
it would appear that this interdigital space is the primary seat 
of the disease, in which cases it will be found that the hoofs are 
quite worn down by the kind of ground upon which the animal 
pastures; but while it is of that nature to wear down the hoofs, 
the space between the hoofs, and also the coronets, must be 
constantly exposed to the action of cold and moisture, until 
the derangement is set up in the circulation of those parts which 
produce the disease, in a similar manner as chilblains in the hu¬ 
man subject. 
The same effect is also sometimes produced in another man¬ 
ner on particular pastures. As the animal moves along, the 
strong coarse grasses are drawn through between the hoofs, 
until, by repeated friction, inflammation in the form of scalding is 
set up, which will be increased or diminished according as the 
cause is continued, or a proper treatment adopted. 
In many eases maggots are found wallowing- in the matter of 
foot-rot, which has led some to suppose that the disease is pro¬ 
duced by some insect. This, however, is only an effect, but not 
a cause of the disease. We find maggots, at certain seasons of 
the year, in every situation where an accumulation of putrid 
animal matter is to be found. I have found them during sum¬ 
mer in canker, thrush, and grease, where the cause was too ap¬ 
parent to be questioned ; and this, I think, is also the case with 
maggots in foot-rot. In all eases much constitutional disturb¬ 
ance is produced; the animal loses flesh rapidly; the flesh is 
red, from the degree of inflammatory fever produced, and unless 
relieved by proper treatment, the animal becomes worn out by 
irritation, and its inability to seek its food; for awhile it shifts 
about upon its knees, but at last dies from irritation and want. 
On examining the feet of a flock, in a short time after they 
have been placed in what is called an infected pasture, it will be 
found that many of them are becoming rapidly affected with 
foot-rot, and that too before any matter has made its appear¬ 
ance, and before any of the sheep have been found lame. In 
some situations, the disease is so rapid in its progress, that in 
two or three weeks the whole flock becomes affected; and this, 
• it is supposed, is produced by infection. 
This case most commonly occurs when sheep have travelled a 
