Difficult of description.

ance, and the necessity there is for some practical rules being laid down, by which we may readily pronounce on the existence or non-existence of this joint disease; but yet I cannot persuade myself that I can represent on paper the rules which have hitherto been my guide. Experience, however, has enabled me to decide on these cases with confidence, having devoted myself more particularly to foot lamenesses.

As we cannot have navicular lameness without inflammation of some part of the joint, which may be seated in the synovial membrane, or in the tendon forming the exterior of the joint, it may be as well to advert to the known symptoms of inflammation First, increased redness; secondly, swelling ; thirdly, pain; fourthly, increased heat. Now, let us see how these four great lights conduct us to the navicular joint.

The first of these characteristics, viz. redness, avails us nothing, the surrounding parts being covered with hair. The second, swelling, is seldom manifest in these cases, the inflamed parts being inclosed by the hoof. Third, pain, although indicated by lameness to exist in some part of the limb, is not sufficient to guide us to the exact site of the disease. Fourth and last, heat: this is too often fallacious; horses, like ourselves, are naturally subject both to hot and to cold feet when in health ; and, further, I have frequently met with chronic

cases of navicular disease where the lameness has been perpetual though slight, in which no increased heat was perceptible in the coronet, or by feeling the surface of any part of the hoof. With the symptoms so unexpressive, I usually pare the soles of both feet extremely thin, when the extra proportion of heat in the lame one will be generally apparent by comparison with the other; but the throbbing of the pastern arteries is a more important criterion.

The other indication, viz. swelling, is only an occasional symptom of the disease, exhibited by a slight fulness round the coronet immediately above the hoof, which, when present, requires the discriminating eye of experience to discern it, and is generally most evident on the inside, towards the indented quarter of the hoof.

feet, not well

the public.

Pointing of the feet, or shifting one foot before Pointing of the the other in the stable, is doubtless expressive of understood by pain, and is of itself a striking symptom of navicular disease; yet it cannot be denied, that there are many horses which have pointed their feet for years, and remained free from lameness even in quick work. In such cases, I am of opinion there exists a dull chronic inflammation in the tendon exterior to the joint, the articular surfaces of the navicular joint remaining quite perfect in structure.

Although all groggy horses do not point, I mean to contend, that a much greater proportion of those

False pointing;

some horses conceal the act.

labouring under navicular lameness do evince this symptom than is generally known.

I usually ask the question, in these cases of lameness, whether the horse points his foot; and am frequently answered by the master and servant, both at the same instant, in the negative; and very fairly too, they not deeming the horse a pointer unless he projects his foot under the manger. However, my rule is, never to place any reliance on this statement; and, therefore, on a quiet examination in the stable, unobserved by the animal himself, I generally catch him in the fact; probably not extending the lame foot out a yard before him, but projecting only about a hand's breadth before the other foot, the muscles of the sound limb tense, and principally supporting the superincumbent weight, whilst all the joints of the lame limb would faintly exhibit a relaxed position, the animal evidently reclining his weight on the extensor muscles and tendons, from the knee to the front of the large pastern joint, not conveying any to the sessamoids, and, finally, receiving it entirely on the front of the foot. Many horses acquire this mode of shifting their weight in the stable without pointing the foot, or betraying the least visible suspicious circumstance, except to a judge expressly on the look-out.

As a proof, I have repeatedly seen the lame foot apparently flat on the pavement, when, on a more

close inspection, I have observed a sound straggling straw or two lying between the heels of the shoe and the pavement remaining entire, and escaping being flattened for a considerable time, in fact, till something disturbs the animal, or attracts his attention. I could very much wish to call this false pointing, in contradistinction to direct pointing. Direct pointing There is also another mode of shifting and easing the foot, which is more obvious, viz. the bent or tremulous knee.

Pain, together with this continued habit of resting, diminishes the size of the limb generally, from the hoof even to the muscles covering the shoulderblade or scapula; but in cases of very long duration, I beg to invite your attention to a considerable alteration in the mass of muscle immediately above the olecranon, called the triceps extensor cubiti, which seems preternaturally contracted, and ceases to exhibit that plump and prominent appearance observable in the sound limb of the living and wellformed horse.

Running the patient in hand at a slow trot materially assists us in forming our diagnosis, by observing the manner in which the lame foot is placed on the ground, whether flat, or principally upon the toe or the heels; but I feel quite at a loss to delineate on paper the peculiar gait of the animal, which I have observed in these lamenesses.

Before I pronounce the case to be navicular lame

Importance of ness, I scrupulously examine the external foot for

accurately

lame foot with

as to the exte

rior.

comparing the every probable cause of lameness; and, having rethe sound one moved both shoes, and pared the soles, I minutely compare the ground surface of the lame foot with the other, to ascertain whether occult contraction has taken place or not: this is not, however, to be expected in every case, at it is well known that many navicular lamenesses have occurred momentarily, as in hunting or other violent exercises. I have omitted to mention, in the requisite order, another not unfrequent cause of navicular disease, viz. the general inflammation consequent upon the accident of casting a shoe, and the animal travelling a considerable distance before the rider may have been apprised of it. It is not very uncommon for such an injury to leave a chronic lameness after the complete reproduction of horn, which may have been a process of many weeks' growth.

We are called upon to treat the navicular disease under various degrees or shades of the same disorder. The case may be either acute or chronic. The lameness may be as sudden and considerable as that which sometimes proceeds from a fractured pastern or cannon bone; or it may be so slight as to require a close inspection on pavement to discern it. The disease may have been of very long or short duration, and yet exhibit lameness only in a slight degree.

A horse that had never shewn an hour's lameness