HOOF TORN FROM THE FOOT BY ACCIDENT.
FIG. 114.—HOOF TORN FROM THE FOOT BY ACCIDENT.
'The dressing was ordered to be allowed to remain on all night, and on the following morning to be removed. The foot was then bathed, as before, in warm water, and the application of the tinctures repeated night and morning. The medicine internally given was castor oil, with tinct. opium, and this, in a diminished dose, was ordered the next morning. Blood was also abstracted from the jugular vein, to the amount of 6 quarts, so as to allay the inflammatory fever set up. The food consisted of bran and linseed, with small portions of hay and water. The mare being in a highly excited state, and suffering such severe pain, the opinion Mr. Taylor gave was that, should she get over the first four days (which appeared quite uncertain), he had no doubt of her ultimately getting well, and also that she would have a perfect hoof formed. It was now left for the owners' consideration, whether they thought the mare worth her keep till such took place, the time mentioned by Mr. Taylor being four or five months. She was seen again the fourth day after the accident, and was then found to be perfectly tranquil and feeding well; her pulse, which at the first visit could not be counted, was now not more than 65 beats in the minute. On removing the dressings, the foot presented a very favourable appearance, the treatment therefore varied only in the application of a linseed-meal poultice over the former dressings of tinctures of opium and myrrh, confining the whole in a soft leather boot. Diet as before, in addition to which give a few oats. Should the bowels become constipated, repeat the castor oil without the opium.
'June28.—The animal was again seen, and appeared to be going on very favourably. The poultices were directed to be discontinued, and the parts dressed every other day with sol. sulph. cupri, as the granulations were getting rather luxuriant.
'July6.—To-day she was found to have gone on so well, having two days before been removed from the slings, that it was thought justifiable to turn her out, protecting the foot with a boot, and ordering the dressings to be repeated.
'July23.—She was seen by me in the field, where I had the boot removed, and so much had she improved, that not less than 2 inches of crust, proceeding from the coronary ring, had been formed, and the foot looked remarkably healthy.
'It will be seen that the accident occurred on June 20, a fortnight after which time I observed the horny crust to be forming from the coronet, and the insensitive laminæ at the same time, in which on every visit an increase of growth was perceptible, and it soon attained a thickness exceeding that of the other hoof, but which at the same time presented a more upright appearance. It was not until three weeks after our first visit that any formation of new sole or frog was to be seen. Of the two the sole was the first, being secreted by the sensitive sole, the growth proceeding from the heels. In like manner the insensitive frog was being produced by the sensitive.
HOOF TORN FROM THE FOOT BY ACCIDENT.
FIG. 115.—HOOF TORN FROM THE FOOT BY ACCIDENT.
'During the last week in October the mare, having her foot protected with a bar shoe plated at the bottom, and so formed as to open without necessity of removing the shoe, in order to facilitate the applications of the tinctures, was put to light work, which has since been gradually increased, and she now performs her usual labour equal to any other horse.
'The growth of the wall or crust and insensitive laminæ is not yet quite complete, nor is the sole, there being wanting about an inch of the horny substance of it, the entire completion of which I should rather doubt, as I mentioned in my former communication that the sensitive laminæ and a small portion of the sole were lacerated, and it is in these parts that the imperfections exist.
'The yet imperfectly-formed wall not admitting of the insertion of nails all around it, the shoe is held on partly by nails and partly by a strap attached to it bound round the coronet.'[A]
[Footnote A:Veterinary Record, vol. iv., p. 182 (B. Cartledge).]
3. 'This case is related by Mr. A. Rogerson, F.R.C.V.S. It occurred to an animal regularly engaged in shunting, and happened through the corner of the shoe becoming "trapped" between a line of metal and the wheel of a truck. It is particularly interesting on account of the photograph accompanying it, and which we here reproduce in Fig. 115.
'The photograph shows plainly the manner in which the holding of the "clinches" on the left side of the hoof has resulted in drawing it off from the foot. Had these clinches, as Mr. Rogerson suggests, been left unfastened, then the accident in all probability would not have occurred. The animal was destroyed.'[A]
[Footnote A:Ibid., vol. xiii., p. 2.]
Definition.—The term 'laminitis' is used to indicate a spontaneous and diffuse inflammation of the whole of the sensitive structures of the foot, more particularly the sensitive laminæ. Usually it occurs in the two front feet, often in all four, and occasionally in the hind alone.
Causes.—In dealing with the causes of laminitis, we will first dispose of those coming under the heading oftraumatic. Correctly speaking, however, lesions of the laminæ thus occurring do not present the same symptoms, nor run an identical course with the disease we now purpose describing, and for which we would prefer to entirely reserve the term 'laminitis.' The fact, however, that traumatic causes are detailed in other works on the same subject compels us to give them mention here.
Strictly traumatic causes giving rise to a limited inflammation of the sensitive laminæ are violent blows upon the foot, either purely accidental, or self-inflicted by violent kicking.
A similar limited laminitis is to be found in the conditions we have described under 'Nail-bound and Punctured Foot.' It is met with also in the injuries resulting from tread and overreach, and in the tissue-changes accompanying corn.
The tenderness following upon excessive hammering in the forge, or of too long an application of the shoe in hot-fitting has also been described as laminitis.
With either of the conditions we have mentioned, it goes without saying that there is either a simple congestion or an actual inflammation, localized or general, of the laminæ of the injured foot. In neither case, however, can the resulting mischief be closely compared with the lesions attending an attack of laminitis proper, a disease which appears to have an almost specific cause, and to run a course peculiarly its own.
The specific cause we have indicated as existing can, in the present state of our knowledge, be only vaguely described as a poisoned state of the blood-stream. This, as clinical evidence teaches us, may result from a variety of causes.
Among these, by far the most common is that state of the circulation induced by excessive feeding with too stimulating or too irritating a diet. In any case, where the use of old oats as a staple diet is departed from, and where the quantity and manner of using the substitute is left to the discretion of careless or unskilled attendants, trouble is likely to ensue. The food more prone, perhaps, than any other to bring about an attack is wheat improperly prepared—that is, uncooked or unground. So much so is this the case that one full meal of this provender to an animal unused to it is sufficient to lead to a train of symptoms often ending fatally.
Beans, peas, barley, rye, new maize, or even new oats, are all liable, if carelessly used, to have the same effect.
It is the laminitis following feeding on new oats that has caused us to apply to the food the adjective 'irritating.' Here, more often than not, the peristaltic action of the bowels is found to be abnormally in evidence, and the excessive use of the diet is always accompanied by a more or less fluid discharge of the intestinal contents.
In addition to the foods we have mentioned, many others might be enumerated, more especially the numerous 'made-up' feeding materials now on the market. Many are composed of substances that may be regarded as absolutely opposed to the correct feeding of a horse, and their use can only be followed by this and other evil results.
Another most fruitful cause of laminitis is a severe and continued inflammatory condition of the system elsewhere. It is the laminitis known to veterinary surgeons as 'metastatic,' and perhaps the two most notable examples of it are the laminitis following a prolonged attack of pneumonia, and the 'Parturient Laminitis' occurring as a concomitant of septic metritis.
Parturient laminitis it is that offers us the most striking illustration of the truth that a poisoned state of the blood-stream is a sure factor in the causation of an attack. From the direct evidence of our senses (namely, manual exploration of the infected womb, and the stench of the exuding discharge) we know that we have in the interior of the womb matter in a state of putrescence. From the experience of previous post-mortems we know, further, that the putrescent matter thus originating often gains the blood-stream, and forms foci of septic lesions elsewhere—liver or lung. When, therefore, during an attack of septic metritis a condition of laminitis supervenes, we are justified in attributing it to the escape of septic matter from the already infected uterus.
In the same category of laminitis from metastasis may also be placed the laminitis occurring as a result of an overdose of aloes. The enteritis thus set up is often followed by laminitis, and that of a serious type.
Prolonged and excessive work upon a hard road is also apt to induce an attack. When this occurs it in many cases resolves itself into a case of cruelty. (See reported case, No. 1, p. 279.)
Laminitis from this cause was frequent among coach and carriage horses in the pre-railroad period, and resulted from attempting to obtain from the animal a faster pace and a greater number of miles than he was physically capable of giving.
In our day, however, it is more often a result of gross feeding, combined with only that amount of work which the horse, if ordinarily fed, would be easily able to perform. An excellent example of this is the laminitis occurring in the Shire stallion when commencing his rounds of service in the spring and early summer. At this season these animals are constantly supplied with a more than sufficient supply of a highly stimulating and nutritious diet. In this case the blood is already in that state in which it is predisposed to the disease. Add to this the unwonted exercise—for during all the winter the animals are idle—and congestion of the venous apparatus of the extremities is not to be wondered at.
Passing from these, the more common, we may consider other and less frequent causes of the disease. Congestion of the laminal blood-vessels and consequent laminitis occurs when animals are made to maintain a standing position for prolonged periods, as, for instance, when making sea voyages. A long and painful disease of one foot, necessitating the whole of the weight being borne by the other, ends often in laminitis of the second member. It may thus occur as a sequel to quittor, complicated sand-crack, suppurating corn, and punctured wounds of the feet.
Laminitis has also been known to occur as a result of septic infection of the blood-stream consequent on the operation of castration. (See recorded case, No. 2, p. 281.)
A sudden lowering of the surface circulation at a time when the animal is excessively perspiring is also said to favour an attack, as also is the giving to drink of cold water to an animal just in from a long and tiring journey. Also, according to Zundel, 'the influence of the season cannot be denied, and it is during the summer months that laminitis is more frequent, while it is rare in winter, as well as in the spring and autumn.'
Further, laminitis has been described as occurring when the animal is at grass, and when all causes—at any rate, active ones—have appeared to be absent. (See reported case, No. 3, p. 282.)
Regarding heredity, we may safely say that, as a cause of laminitis, it may be almost totally disregarded. That a bad form of foot, either a flat-foot or a foot with heels contracted, and already thus affected with a mild type of inflammation, did not offer a certain predisposition, we should not like to assert. There must, however, be an exciting cause—namely, a poisoned condition of the blood-stream. This latter cannot, of course, be in any way regarded as hereditary.
In short, the dietetic cause is by far the most common, and, in prosecuting inquiries as to the starting-point of an attack, the veterinarian's attention should be directed in the main to that particular.
Symptoms.—Laminitis is always ushered in by a set of symptoms indicative of a high state of fever. The pulse is raised from the normal to as many as 80 or 90 a minute, muscular tremors are in evidence, the respirations are short and hurried, and the temperature rises to 105°, 106°, or 107° F. The visible mucous membranes are injected, that of the eye, in addition to the hyperæmia, often tinged a dirty yellow. The mouth is dry and hot, the urine scanty, and the bowels frequently torpid. As yet, however, the walk is sound.
Called in during this early stage, the veterinarian is often puzzled as to the exact significance of the symptoms. Enteritis, lymphangitis, or pneumonia he knows to be often heralded in the same manner. In this connection, Zundel says: 'Laminitis, in most instances, is preceded by certain general symptoms, such as are premonitory of the invasions of ordinary inflammatory diseases, but of an uncertain significance.'
So far we agree with him, but to what we have already said we would add that, even in this early stage, there is an additional symptom, unmentioned by Zundel, which often leads one to an exact diagnosis. The feet are in turn lifted a short distance from the ground, and almost immediately replaced. This movement ('paddling,' we may term it) is constant, the animal appearing to obtain ease in no one position for more than a few moments at a time.
Seen but a few hours later, when the swelling caused by the hyperæmia and outpouring of the inflammatory exudate has led to compression of the sensitive structures within the horny box, the symptoms presented admit of no misreading, save by the most casual and careless observer. The patient now stands as though fixed to the ground. The pulse is hard and frequent, the respirations tremendously increased in number, the body wet with a patchy perspiration, and the countenance indicative of the most acute suffering. Only with difficulty, and often only at the instigation of the whip, can the animal be induced to move. This he does by throwing his weight, so far as he is able, on to the heels of the feet affected, and putting the feet slowly forward in a shuffling and feeling manner. The feet themselves give to the hand a sensation of abnormal heat, percussion upon them with the hammer is followed by painful attempts at withdrawal, while any effort we may make to remove one foot from the ground is useless, so great an aversion does the animal show to placing a greater weight upon the opposite foot.
According as the front-feet alone, the hind-feet alone, or all four feet are affected, the symptoms will vary.
With all four feet diseased, the animal stands with the two front-feet extended in front of him, while the hind-limbs are at the same time propped as far beneath him as is possible. The horse is, in fact, standing upon the extreme hindermost portions of the feet.
Why the animal should thus distribute his weight is easily explained. Standing in the normal position, the body-weight is borne by the sensitive laminæ, the sole, of course, sharing in the burden, but the laminæ taking by far the greater part of the pressure thus exerted. With the vessels of the laminæ gorged with blood, and the laminal connective tissue infiltrated with a profuse inflammatory exudate, the most excruciating pain is bound to result by reason of the compression of the diseased tissues within the non-yielding structures. In some little measure the suffering animal may afford himself relief by partly removing pressure from the fore-parts of the hoof. When placing the body-weight behind, the pressure, instead of falling upon the highly sensitive laminæ, is directed to the follicular and fatty tissues of the plantar cushion: from there, with only a small portion of the sensitive sole intervening, to the horny frog, and from thence to the ground.
The same distribution of weight also places the foot in a position of greatest expansion, thus, by giving greater room to the diseased parts, again affording relief of pressure on the inflamed lamina, while it at the same time relieves of weight the foremost portions of the sensitive sole.
With the fore-feet alone attacked, the animal affects exactly the same position of standing as that just described. The fore-feet are again extended, and the hind propped far beneath him. The fore extended, in order to obtain the relief occasioned by standing on the heels; the hind in this case carried forward in order to take a greater share of the body-weight, and thus relieve the congested members in front.
With the hind only attacked, then the fore and the hind feet are more closely approximated than in the normal position. The reason, of course, is that the hind-feet are carried forward in order to be placed upon the heels, while the fore are taken backwards to relieve the hind of the body-weight.
In like manner the movements of the animal will vary with the feet affected. With only the front-feet diseased the animal is, comparatively speaking, comfortable. The hind-feet take the weight, and the animal stands for long periods together, resting alternately first one fore-foot and then the other, moving often in a circle of which his body is the radius, and his hind-limbs the centre. If urged to move forward, then immediately his countenance and movements manifest the pain to which he is put. Only with reluctance does he cause the fore-feet to take weight. They are shuffled forward quickly one after the other, so that weight may not be placed upon them for one instant longer than is necessary, and the hind-limbs immediately brought again with two short, awkward movements beneath the body. Progress thus takes place in a succession of movements 'half hobble,' 'half jump.'
Painful though this may appear, progress is still more difficult when the hind-feet alone are diseased. Afraid that, in placing his fore-members freely forward, he will add to the pain in his hind, the walk takes place in a series of extremely short steps, with the feet more or less closely approximated. The gait is thus rendered extremely awkward, and Zundel, by saying that 'the animal appears as if treading on sharp needles,' most fitly describes it.
Movement with all four feet affected, though less awkward in appearance, is doubtless more painful than in either of the other conditions. Here the animal can hardly be induced to shift his position at all. Only by flogging, and that severe, can he be made to go forward. When so induced to move, the agonizing pain to which the patient is subjected may be gathered by noting his countenance and manner of progression.
With each movement forward, muscular tremors affect the limbs; each step is short, jerky, and convulsive; the respirations and pulse are almost immediately greatly quickened, and the lower lip is hung pendulous, and moved almost unconsciously up and down with a flapping noise against the upper. A patchy perspiration breaks out about the body and quarters, and the tail is outstretched and quivering. At the same time the lines of the face become drawn, the commissures of the lips pulled upwards, the eyes staring and haggard, the eyelids puckered, the nostrils extended, and the whole expression indicative of the intense and agonizing pain of the disease.
One can perhaps better give one's client some vague idea of the patient's suffering by likening the pain to the throbbing sensation of a festered finger-nail. Tell him that each hoof of the horse is similarly, or, if anything, more delicately, constructed, that in each foot the same process of 'festering' is going on, and that upon them the animal has perforce to stand.
As one might expect, the position of greatest ease is the decumbent. Strange to say, though, in many cases of laminitis the animal persists in maintaining a standing posture. Once down, however, one has sometimes the greatest difficulty in persuading him again to rise. The lying position is so long maintained that bedsores begin to make their appearance, and the animal rapidly loses flesh, not only by reason of the fever and the pain, but by giving to rest the time he should normally give to feeding.
Difficulty in rising is greatest when all four feet are affected; isnearlyas great when the hind-limbs only are in trouble, but is least when the disease exists alone in the two fore-feet.
THE COURSE OF THE DISEASE AND ITS PATHOLOGICAL ANATOMY.—As with most inflammations of any severity, so with this we may consider the pathological changes taking place in the foot under three headings: (a) The period of Congestion; (b) the period of Exudation; (c) the period of Suppuration.
(a)Congestion.—In the early stages of laminitis there is a state of engorgement of the vessels of the keratogenous apparatus generally, but more particularly the laminal portion of it. With the hoof removed at this stage the sensitive laminæ are found to be swollen, dark red in colour, and affording a distinct feeling of increased thickness when pressed between the fingers, Incised, there escapes from the cut surface a large flow of dark venous-looking blood. At this stage hæmorrhages of the laminal vessels occur. The escaping blood infiltrates the surrounding connective tissue, and in many cases destroys the union between the horny and sensitive laminæ. This change is most noticeable in the region of the toe and the commencement of the quarters, the os pedis appearing as though pushed backwards by the escaping fluid collected between the wall and the bone. In severe cases, fortunately but rarely seen, the blood so escaping continues to infiltrate, and separate the tissues until it is seen to be freely oozing at the region of the coronet. (See reported case, No. 1, p. 279.)
(b)Exudation.—The period of exudation marks the outpouring of the inflammatory fluid. This, even more than the hæmorrhages attending the stage of congestion, tends to destroy the intimacy between the sensitive and the horny laminæ, leading finally to their complete separation at the region of the toe. Fig. 116 illustrates this state of affairs after laminitis has existed for a week. The sensitive and horny laminæ are here shown to be distinctly separated from each other, a well-marked cavity existing between them, which cavity is greatest in extent at the toe of the os pedis. With the sensitive structures thus detached from the wall, it is evident that very much that formerly held the os pedis in normal position has been destroyed. What then happens is that the whole of the body-weight is placed upon the sole. Never intended to bear the strain thus imposed, it naturally sinks. With the sinking is a corresponding 'dropping' of the pedal bone—in fact, of the whole of the bony column. Seeing that the structuresabovethe hoof are still normally adherent to the bones, it follows that they must, as the os pedis sinks, be carried with it. As a consequence we get a marked depression at the coronet (see Fig. 117,a), which depression may be often noticed after the second or third week of a severe attack of the disease.
LONGITUDINAL SECTION OF A FOOT WITH LAMINITIS OF EIGHT DAYS' STANDING.
FIG. 116.—LONGITUDINAL SECTION OF A FOOT WITH LAMINITIS OF EIGHT DAYS' STANDING. The separation between the sensitive structures and the hoof is indicated by a dark line. The cavity is filled with exudate. It will be noted that as yet there is little change in the position of the os pedis.
Here, again, though to a greater extent than that caused by the hæmorrhage alone, the os pedis appears to be pushed backwards, the space at the toe between the bone and the horny box being closely filled with the yellow, slightly blood-stained exudate. This condition is well depicted in Fig. 117.
LONGITUDINAL SECTION OF A FOOT WITH LAMINITIS OF FOURTEEN DAYS' STANDING.
FIG. 117.—LONGITUDINAL SECTION OF A FOOT WITH LAMINITIS OF FOURTEEN DAYS' STANDING.a, The depression at the coronet caused by the dropping of the bony column within the horny-box:b, a portion of the sensitive sole pushed downwards and forwards by the descending os pedis.
With the descent of the os pedis we get in many cases a penetration of the horny sole (see Fig. 117), leading always to serious displacement of the sensitive sole (see Fig. 117,b), and often to caries of the exposed bone.
The backward displacement of the os pedis may be accounted for in two ways. Firstly, the greater vascularity of the membrane covering its front leads to a greater outpouring of inflammatory fluid in that particular position. Here, therefore, loss of adhesion with the wall is greatest, while into the cavity so formed is poured a large quantity of a fluid that is practically incompressible. The os pedismustbe pushed backwards. Secondly, the manner in which the animal distributes his weight—namely, upon the heels—is calculated to aid in the bone's backward movement, for with his feet in this position tension upon the extensor pedis is relaxed, while that upon the flexor perforans is greatly increased.
(c)Suppuration.—Should the animal survive the pain and exhausting calls made upon his system by the accompanying fever of the foregoing conditions, the case ends either in resolution or suppuration. When suppuration occurs it is found, as a rule, at the sole, leading to almost entire separation of the sensitive and horny structures. The pain, if possible, is even worse than in either of the foregoing stages, and relief for the suffering patient is only obtainable by the natural exit of the pus at the coronet, or by giving it escape with the knife at the sole. As a rule, suppuration in laminitis is rare, and then only occurs when the disease has been of some several days' duration. It has been the author's experience, however, to meet with it in a case but three days' old. This particular animal had laminitis restricted to the hind-feet. The condition was diagnosed and pus liberated at the sole of one foot during the third day of the lameness. The animal was cast on the fourth day, and pus obtained from the sole of the opposite foot.
Complications.—In a moderate case, carefully treated, laminitis terminates at the end of three or four days in resolution. The general symptoms of fever gradually subside, the appetite returns, and the walk becomes easier. Cases thus terminating fortunately leave behind them no change of serious importance, either in the sensitive tissues or in the horny envelope. Should resolution, however, be longer delayed, then the case, although eventually terminating successfully so far as soundness in gait is concerned, leaves more or less evidence behind in the shape of rings about the wall and alterations in the build of the sole.
When the happy ending of rapid resolution is denied us, then, in addition to the condition we have described as suppuration, we may meet with one or other of the following complications:
(a)Metastatic Pneumonia.—This complication is not uncommon, and, when occurring, more often than not ends fatally. It may be accounted for indirectly by the greater work the lungs are called upon to perform in carrying out the increased number of respirations occasioned by the general fever and pain, and directly by the poisonous materials circulating in the blood-stream.
(b)Metastatic Colic.—This may be either a subacute obstruction of the bowel or an enteritis accompanied by an offensive purge.
A striking case of the former is related in theVeterinary Journal(vol. xvi., p. 180) by H. Thompson, of Aspatria. Here no evacuation of the bowels occurred for three days, and the pains of laminitis were added to by the usual pains of intestinal obstruction.
The colic of enteritis is in some cases caused by the nature of the food, giving rise to laminitis. In our opinion, however, it is more often occasioned by the drastic action of the aloes nearly always resorted to in the treatment of the disorder. As does the pneumonia, the enteritis thus brought about nearly always has a fatal termination.
(c)Gangrene of the Structures within the Hoof.—This complication is the one most to be dreaded. It occurs as a result of the great pressure exerted by an excessive exudation, and doubtless affects first the laminæ and softer structures. Once commenced, however, it rapidly extends to death of the other structures (ligament, tendon, and even bone), and gives a fatal ending to the case.
That gangrene of the tissues ("mortification" as our older writers called it) has occurred is soon made evident to the veterinarian by the symptoms shown by the patient. The agonizingly acute pains suddenly subside, the feet are placed firmly and squarely to the ground, and the animal walks with ease. Perhaps but the night before the patient is seen racked with excruciating pain; the morning sees the astounding change of apparent absolute recovery. Too well, however, the eye of the experienced veterinary surgeon sees that such is not the case. Even before proceeding to take a record of the other symptoms, he knows that it is but the commencement of the end. Methodically, however, he notes the other conditions. The pulse he finds small and imperceptible, save at the radial. The thermometer registers a subnormal temperature, the extremities are cold, and cold sweats bedew the body. To the same experienced eye the countenance of the animal is almost suggestive of what has occurred. The drawn and haggard expression, to which we have previously referred, becomes more marked, and the angles of the lips are drawn back in what has been described by some writers as a 'sardonic' grin.
We can best express what the whole look of the animal's countenance indicates to us by saying that it gives us the impression that the animal himself knows that some serious change, and a change fatally inimical to his chances of life, has taken place in his feet.
It may be that in some odd cases, although it has not yet been our lot to meet with them, gangrene may terminate in the casting off of one or more hoofs. Needless to say, there can still be but one termination to the case.
(d)Periostitis and Ostitis.—This complication is referred to by other writers under the term of 'Peditis.' It signifies, of course, that the periosteum and the bone have become invaded by the inflammatory process. It is our opinion that these two conditions, even including an actual arthritis, always exist, even in an attack of laminitis that ends favourably. We do not claim, however, to be able to relate any means, save that of post-mortem examination, by which it may be singled out from the other changes occurring in the foot. The high fever and pain occasioned by the inroads of the inflammation into the other sensitive structures serves to effectually mask whatever evidence of it we might otherwise obtain. It may be sometimes only small in degree, but we feel confident that inflammation, at any rate of theouterlayer of the periosteum, is in laminitis constant even, we repeat, in a mild case.
SHOWING CHANGES IN THE OS PEDIS WITH LAMINITIS OF LONG STANDING,
FIG. 118.—SHOWING CHANGES IN THE OS PEDIS WITH LAMINITIS OF LONG STANDING, (a, Viewed from the front;b, viewed from the side.) The porous condition of the bone, which is here shown, is a result of a rarefying or rarefactive ostitis. This specimen also illustrated (what the photograph cannot show) an accompanying condition of condensation of bone, or osteoplastic ostitis. (For a fuller description of the changes occurring in these forms of ostitis, see Chapter XI.)
When the case is a serious one we have ample evidence to show that ostitis exists, and exists in a severe form. The bones become vastly altered in shape, a process of absorption leads to the formation of large, irregular cavities within their substance, and what of the bone is left is rendered hard and ivory-like (condensed) near what was the original centre, while the edges and other portions show often a tendency to become brittle and porous.
Fig. 118 illustrates the effects of a severe ostitis in pedal bones removed from hoofs with laminitis of several weeks' standing.
(e)Chronic Laminitis.—The most common complication—or, perhaps, rather we should term it 'sequel'—to acute laminitis is the chronic form of the disease. For this condition we have reserved a separate section of our work. It will be found described in Section B 1 of this chapter.
Diagnosis and Prognosis.—One is almost tempted to state that the diagnosis of laminitis offers no difficulty. In the very early stages, however, it may, as we have already indicated, be mistaken for the oncoming of Enteritis, Lymphangitis, or even Pneumonia. The paddling of the feet may help us. If this is absent, however, nothing but a most careful examination, or, if necessary, the withholding of our opinion until the following visit will prevent a blunder being made.
Even when well established, laminitis has been mistaken for paralysis, for tetanus, for rheumatic affections of the loins, or even for some undiscovered affection of the muscles of the arms and chest. This latter is no doubt suggested to the uninitiated by the reluctance the animal shows to move the musclesapparentlyof that region, and led the older writers to give to the disease its name of 'Chest-founder.' It is only fair to add, however, that these blunders in diagnosis are nearly always committed by persons without a veterinary training.
Thus warned, the veterinary surgeon of average ability should have no difficulty in establishing a distinction between the diseases we have enumerated as likely to be confounded with it, and the one this chapter is describing.
The prognosis in laminitis should, in our opinion, always be guarded. No advice given in a work of this description can be of any real use, for every case must be judged entirely on its merits. The severity of the symptoms, the cause of the attack, the complications, and the idiosyncrasies of the patient, have all to be taken into account. These the veterinarian must be left to judge for himself.
Treatment.—The treatment of acute laminitis in its early stage must be based upon the fact that we have to deal with a congested state of the circulatory apparatus of the whole of the keratogenous membrane. This fact was well enough known to the older veterinarians. It is not surprising, therefore, to learn that jugular phlebotomy was at once resorted to as the readiest means of relieving the overcharged vessels of their blood. As a matter of fact, bleeding from the jugular is still advocated by modern authorities. We cannot say, however, that we unhesitatingly recommend it. Mechanically, of course, the removal of a large quantity of blood is bound to result in a lowering of the pressure in the vessels. The effect, however, is but transient. Blood removed in this way is again quickly returned to the vessels so far as its fluid matter is concerned, and the pressure, removed for a time, is again as great as before. With the other and more vital constituents of the blood-stream—namely, the corpuscles—restoration is not so rapid. We have, in fact, a weakened state of the system, in which it is probable it will not so successfully combat the adverse conditions the disease may induce.
With these prefatory remarks, we may advise bleeding under certain conditions. The quantity removed must be moderate (7 to 8 pints), and the pulse and other conditions must show no signs of weakness or collapse.
Local bleeding, either from the toe or the coronet, is also advised. In the former situation the sole is thinned down until a sufficient flow is obtained, while at the coronet scarification is the method adopted. Bleeding locally, however, is far less effectual than the jugular operation. Neither must it be forgotten that wounds in these situations, more particularly at the toe, are extremely liable, especially with the existing poisoned state of the blood-current, to take on a septic character. What might possibly have remained a comparatively simple inflammation is induced by the operation itself to terminate in the more complicated and serious condition of suppuration.
Other means of combating the congested state of the membrane are principally those of local applications. With many veterinary surgeons warm poulticing is still largely advocated and practised. We do not believe in it. Warmth, as a means of removing local congestion, can only be successful when appliedwidelyround the congested area, and so dilating surrounding bloodvessels and lymphatics. Applied to the congested area itself, and to that alone, it is almost worse than useless.
With the foot, both around and below it, a surrounding area is denied us. The only vessels we are able to dilate with the warmth, and so enable them to carry off the fluid from the congested foot, are those in the limb above. That poulticing cannot be successfully there applied is self-evident. Apart from that, it is an open question whether poultices may not do actual harm in inducing suppuration in cases where, probably, it would not otherwise occur.
For these reasons we hold to the opinion that when a local application is determined on it should be a cold one. Various methods of applying cold are in vogue. Cold swabs are perhaps most in favour. They must, however, bekeptcold. When a suitable water-course, pond, or other expanse of shallow water is at hand, then the animal may be kept standing therein, or preferably walked about in it. When suitable apparatus is obtainable, a constant stream over each foot from a rubber hosepipe is most beneficial.
Astringent baths, containing solutions of alum, of copper sulphate, of iron sulphate, or of common salt, or composed of a mixture of two or more of the salts mentioned, may also be used with advantage. In addition to the fact that such solutions are for a time below the temperature of simple water, we have the advantage that they have also a more or less antiseptic property.
While on the subject of the relief of the congestion, we must not forget to mention a treatment which we ourselves have practised with considerable success—namely, that of forced exercise. It appears to have been first brought into prominence by Mr. Broad, of Bath, and the two terms 'Forced Exercise and Rocker Shoes' and 'Broad's Treatment' have come to be synonymous.
The Broad shoe is a shoe with a web of quite twice the thickness of the animal's ordinary shoe, and has this web gradually thinned from the toe backwards until at the heels the shoe is at its thinnest (see Fig. 119).
The excessive thickness of the shoe serves two purposes. It allows of the requisite amount of slope being given to the web, and so enables the animal readily to throw himself back on to his heels, a position in which, as we have already indicated, he obtains the greatest ease. It also minimizes to some extent the effects of concussion.
SEATED ROCKER BAR SHOE (BROAD'S) FOR TREATMENT OF LAMINITIS.
FIG. 119.—SEATED ROCKER BAR SHOE (BROAD'S) FOR TREATMENT OF LAMINITIS.
With forced exercise, as practised by Mr. Broad, this shoe is first applied, and the animal afterwards made to walk upon soft ground, or even upon the roadway, for a half an hour to an hour and a half three times a day.
For our own part, we consider the shoe to be almost if not quite superfluous, so far as its influence upon the progress of the disease is concerned. We therefore dispense with it, and have the animal exercised in his ordinary shoes. To do this, the patient has sometimes to be severely flogged into taking the first few steps. After that progress gradually becomes easier.
It has been said to be cruel. In so far as we knowingly, and of set purpose, occasion the animal pain, cruel it undoubtedly is; but it is cruelty with an aim that is truly benevolent, and the object of our benevolence is the animal upon whom the cruelty is practised.
One word of advice is needed. The forced exercise must be commenced early. In the later stages, when the stage of congestion has passed from that to the acuter stages of the inflammation and the outpouring of the inflammatory exudate, then forced exercise cannot be safely commenced. The loss of adhesion between the pedal bone and the horny box, which we know to be then existent, negatives its advisability.
By many it is advised to always remove the shoes. From what we have already said, it will be seen that this is not our practice. But one argument in favour of so doing appears to us to carry weight, and that is that 'dropping' of the sole is probably prevented from becoming so marked. That condition, however, is entirely dependent upon the changes occurring within the horny box. It is bound to occur with the animal shod or unshod, and to reach a stage when only contact with the ground prevents its further descent. The complication then sometimes following—namely, penetration of the sole by the bone, is not prevented by having the shoes removed. It may, in fact, be thus rendered more likely.
Internal treatment consists in the exhibition of suitable febrifuges and the administration of a dose of aloes.
With regard to the wisdom of the latter proceeding, opinion seems to be divided. Personally, we hold an open mind concerning it. This much is certain: in many cases of laminitis—those cases which have their origin in overfeeding with an irritating food—there is already a strong predisposition to enteritis. The administration of aloes in this case is extremely apt to induce a fatal super-purgation. Aloes is, again, contra-indicated when the laminitis is a result of excessively long journeys, and the patient is already greatly exhausted. Neither can it be advocated in the laminitis occurring as a sequel to septic metritis or to pneumonia.
On the other hand, when the disease has occurred as a result of long standing in the stable and an overloaded condition of the bowels, or where one full meal of some constipating food, such as whole wheat, pea or bean meal, wheat or barley meal, has occasioned the attack, then a dose of aloes at the commencement of the treatment is productive of good.
Suitable febrifuges are found in potassium nitrate, potassium chlorate, sodium sulphate, or magnesium sulphate, either of which or a mixture of two or more of them, the animal will readily take in his drinking-water.
The administration of sedatives is also indicated. In this connection aconite will be found most useful. More especially in the early stages of the disease, when pain is excessive and the temperature high, will its good effects be noticed. This also the animal will often take in his drinking-water. We have been in the habit of so prescribing the B.P. tincture in 1/2-dram doses three times daily. By its use the temperature is rapidly lowered, the pulse reduced in number and in fulness, and the pain in some instances perceptibly diminished. With others hypodermic injections of morphia and atropine have given equally satisfactory results.
Needless to say, good nursing is asine quâ non. During the first stages of the fever a light and easily digested diet should be allowed—bran-mashes, roots and grass when obtainable, and a carefully regulated supply of water. The animal should be warmly clothed and the box well ventilated, even to the opening of the doors and windows. Only in this way is pneumonia as a sequel sometimes prevented. The patient's comfort should be attended to in providing him with a suitable bed. Anything in the shape of long litter should be avoided. When nothing else is at hand, litter that has already been broken and shortened by previous use is best. With this the box floor should be thickly covered, and matting of the material prevented by constant turning. A good bed for the horse with laminitis is peat-moss mixed with short straw. This, without being dragged into irregular heaps, remains springy and elastic with but little attention. Better than all, however, especially with good weather, is an open crewyard. Here the animal has an abundance of fresh air, has a bed that is always soft, and has plenty of room in which to get up and down with some degree of ease.
Leaving the dietetic and medicinal, we may consider other treatments of laminitis that come more particularly under the heading of operative.
The first matter that here demands our attention is that of allowing the exudate to escape at the sole. If after the expiration of three or four days pain and other symptoms of distress continue, then it may be judged that the inflammatory exudate has made its appearance. Operative measures allowing of its escape, though not giving absolute ease, do undoubtedly relieve the more marked expressions of suffering, and should be at once determined on. To do this completely it is necessary to cast the animal. The sole is then thinned at the toe with the drawing-knife until the sensitive structures are reached. A flow of yellow and sometimes blood-stained discharge is immediately obtained, and the sole itself found to be underrun to a considerable extent. An opening sufficiently large to admit of free drainage (about the size of a half a crown-piece) is made, the wounds antiseptically dressed, and the hobbles removed.
If showing an inclination to do so, the animal should then be allowed to remain and rest. In one instance in which we so operated (a case of laminitis in the hind-feet alone), the relief given was at once manifested. For three days previously the animal had remained standing in agonizing pain. On the fourth he was cast, and the discharge—partly inflammatory exudate, and partly a sanious foetid pus—liberated. The hobbles were removed, and the animal allowed to remain down while our attention was drawn to another case. This attended to, we walked back to the field where, our first patient was lying. His breathing, but a short time before distressedly short and catching, was now so slow and deeply regular that for one brief moment the thought flashed across our mind that he was dead. He was in aprofoundsleep.
Other operators sometimes give the exudate escape while making the grooves in what is now known as 'Smith's Operation.'
In this operation the hoof is so grooved as to allow of its expansion, so relieving the pressure on the sensitive structures within it. Incidentally, the inflammatory exudate is given exit.