794 
DISEASES OF THE FOOT. 
at the posterior end and extends forwards. The necrotic fragment may 
separate partially, but, as a rule, it maintains connection with the 
healthy tissue in front, to which the process gradually extends. Never¬ 
theless, spontaneous separation and recovery is possible when disease is 
limited to the posterior third of the cartilage. The cartilage so called is 
composed of two tissues : the superficial layer being truly cartilaginous, 
the deep fibrous. The cartilaginous layer is thickest in front. At the 
back it forms small plates, separated b} 7 septa of connective tissue, an 
arrangement which favours delimitation, inasmuch as these septa constitute 
boundaries at which necrosis is sometimes arrested. 
Necrosis of the os pedis, suppuration in the pedal-joint, and cellulitis 
of the subcoronary connective tissue or fibro-fatty frog sometimes occur 
as complications. The first only increases the duration of the process; 
but inflammation of the pedal-joint generally proves fatal, whilst purulent 
inflammation of the fibro-fatty frog and of the subcoronary connective 
tissue are often the forerunners of other grave conditions (see foregoing 
section on “ Picked-up Nails,” &c). 
Symptoms. As purulent inflammation of the parachondrium is the 
starting-point of quittor, the first symptom is a diffuse swelling of the 
coronet and of the bulb of the heel. This inflammation may in rare 
instances result in resolution ; but generally an abscess forms, and dis¬ 
charges pus mixed with blood, after which the swelling partially dis¬ 
appears, leaving a sinus 1 to 2 inches in depth. After some time this 
closes up and a fresh swelling forms, which takes the same course. The 
process is repeated at varying intervals. Often there are several sinuses 
which communicate with one another. In old-standing cases the wall 
of the hoof is thrust outwards and the horn is ringed, while the coronet 
may show the scars of several old sinuses. The depth to which ring- 
formation has extended is an approximate guide to the age of the con¬ 
dition, if one bears in mind that the wear of the foot is about inch per 
month. 
Lameness is not often very severe, and may be so slight as to allow 
the animals to continue at slow work. It bears no fixed relation to the 
seriousness of the disease. With each recurrence of inflammation, how¬ 
ever, the pain increases, and, if the pedal-joint or fibro-fatty frog be 
implicated, it always becomes very marked, and then shows the peculiarities 
distinctive of disease in the regions named. As the capsular ligament 
of the pedal-joint is in close contact with the inner surface of the anterior 
portion of the cartilage, the pedal-joint is occasionally invaded—almost 
necessarily with fatal results. This termination would he more common 
but for the fact that the capsular ligament usually becomes inflamed and 
thickened by a deposit of fibrous tissue before necrosis actuallv extends 
to the cartilage in contact with it. 
