’The owner informed me that she had not been allowed any corn for two months, and that she had no distance to travel on the road from the common.

’Though on such a poor pasture, the mare was very fat; she had never been unwell before this attack.

’This is the first case I have seen of laminitis occurring when the animal was on grass.’[A]

[Footnote A:  Veterinary Journal, vol. ix., p. 176 (W.  Stanley Carless).]

B. CHRONIC.

1.  CHRONIC LAMINITIS.

Definition.—­A low and persisting type of inflammation of the sensitive structures of the foot, characterized by changes in the form of the hoof, and incurable pathological alterations within it.

Causes.—­Chronic laminitis more often than not is a sequel to the acute form we have just described.  With an attack of acute laminitis that defies treatment, and does not end in resolution in from ten days to a fortnight, then the chronic form may be expected.

The brittle horn, convex sole, and other changes we have described under Pumiced Foot may, however, be regarded as a chronic laminitis, and this condition, as we have already indicated in Chapter VI., may run a course slow and insidious from the onset.

Symptoms.—­When the disease arises without previous acute symptoms, the first thing noticeable is an alteration in the gait.  The animal begins to go feelingly, especially when first moved out from the stable.  Our opinion is asked as to the cause of the lameness, and an inspection is made.  With the changes in the form of the hoof as yet wanting, we have nothing to guide us, and other causes for the lameness suggest themselves, probably corns.  Evidence of these is not forthcoming, and we in all probability withhold our opinion until a later visit.  On the second or a subsequent call we are perhaps lucky enough to find our patient down.  Diagnosis is then rendered easier.  Made to rise, the animal stands in the attitude we have described as indicative of laminitis.  We have him walked and trotted out.  The symptoms of tenderness disappear, and the animal soon goes fairly sound.  He is, in fact, workable—­that is, by anyone who is careless as to the comfort of his beast.

When following an acute attack, we have the most marked symptoms of pain and distress, somewhat abating after the second or third week.  The walk, however, is still painful, and, for a short time after rising from the ground, even difficult.

In short, in both cases we have the horse going on his heels, with a walk that is painful, and with symptoms of pain that are most apparent when moved on after a rest.

Later, the changes in the form of the hoof begin to appear.  It seems to have lost its elasticity, and is seen to be dry and chippy, and to have become denuded of its varnish-like outer covering.