With the flexor tendons attacked pain is always very great, and lameness is excessive.  This, however, is not sufficiently characteristic to enable us to determine the precise seat of the necrotic changes.  Later, however, a tender but hard enlargement made its appearance in the hollow of the heel, which enlargement, later still, became soft and fluctuating.  At this stage there is also considerable swelling along the whole course of the tendons, as high up as the knee or the hock.  The foot is carried forward with all the phalangeal articulations flexed, and in many cases the limb is unable to take weight at all.  Manipulated after the manner of examining the tendons for sprain, this swelling is found to be extremely painful.  The animal flinches from the hand, and shows every sign of acute suffering.  This condition may, in fact, be mistaken for sprain, and is only to be distinguished from it by carefully noting the history of the case—­first, the appearance of the swelling in the hollow of the heel, and, secondly, the after-swelling of the upper portions of the tendons.

The formation of the abscess, the after-discharge of its contents, and the final establishing of a fistula, are processes greatly prolonged in this form of quittor.  It will readily be understood why this should be so when one remembers the depth at which the suppurative process is going on, the thickness of the metacarpo-phalangeal sheath, and the resistant nature of the material of which this latter is made, and which must be penetrated before the condition becomes observable.

After the opening of the abscess, which usually takes place in the hollow of the heel, there is left the fistulous wound which obstinately refuses to heal.  Or it may be, again, that there are several of these fistulas, each opening in the heel, and the mouth of each marked by a small, ulcer-like projection.  The discharge continually oozing from these keeps the heel constantly wet with a thick purulent discharge, which is nearly always blood-stained, and very often foetid.

This constitutes what is known as tendinous quittor in its worst form, for more often than not there is associated with it inflammation of the navicular bursa, caries of the bones, or arthritis of the pedal articulation.

With the extensor pedis attacked matters are not quite so grave, in spite of the fact that the articulation is closely situated thereto, for in this case the more superficial position of the diseased structure allows both of readier exit of the discharges and of easier removal of the necrosed portion and after-treatment of the wound.

(c) Caries of the Bones.—­Portions of the os pedis, more especially of its wings, and therefore usually occurring in conjunction with necrosed cartilage, become carious in quittor.  In many cases it is impossible to say with certainty when this has occurred.  In a few instances, however, the exuding discharge gives evidence of what has happened.  It is thin, but extremely offensive, with the characteristic odour of decayed bone or tooth, and with a feel that is gritty with contained particles of broken-up bone.  If, with a discharge of this nature present, the probe also conveys to the fingers the sensation that bone is reached, then diagnosis may be sure.