Part 10

The fact here recorded has certainly been generally overlooked; and Mr. Percival deserves the gratitude of his professional brethren for directing their observation to the point. Every practitioner, however, has met with instances in which the molars were implicated. There are two forms of disease to which these teeth are liable; caries, or decay, and a loss of vitality, or death. The death of a tooth has not hitherto been observed upon by veterinary authors, but it is not rare. The causes which may give rise to it cannot be accurately stated, though they may be conjectured. The vessels that nurture the fang and ramify through the pulp, are small and delicate; the alveolar cavities are thin, some of them in the upper jaw being not thicker in parts of their walls than brown paper. The force of the masticatory muscles is very great, and if any hard substance be taken between the teeth, it is easy to imagine that the minute arteries of the fang should thereby be ruptured. The effect produced upon the pulp, and the transient agony occasioned by biting a piece of hard crust, are familiar to every human being; nor can we suppose that the horse's teeth, especially when the greater strength of its muscles is duly considered, are not liable to similar and proportionably greater injury. There may be no history to such a case, no record of the date when the occurrence took place; for the horse is not always watched during the time of its feeding, nor were it watched, is it possible that the groom would attribute the sudden exhibition of pain to the right cause. The primary effect is therefore misinterpreted or unnoticed; but after a time it is remarked that the creature is longer than its companions emptying the manger; then it begins to quid its hay,--that is, the hay is taken into the mouth partially masticated and formed into a pellet or round mass; but instead of being swallowed, the prepared morsel is allowed to fall from the mouth. Should no advice be taken, the horse becomes bad in its coat, and loses flesh. No amount of corn, or extra grooming, will restore it to condition; medicines may be administered with no better effect. The disease is strictly local in its nature, and the constitutional symptoms are only sympathetic. Should the affection still be suffered to proceed unchecked, the animal is continually moving its lips; either it is restless in the stable, or leans the head against the manger, and neglecting the food which is before it, remains dull and quiet, the eyes half closed, and the breathing quickened. A dose of medicine seems to do it some temporary good, but the purgation has hardly ceased before the symptoms reappear; saliva runs from the mouth, and the food in the manger is rendered sloppy, almost like to a mash, before it is eaten; the bones of the face at last swell; the breath becomes fetid; and a thick offensive purulent discharge issues from one of the nostrils. That discharge is not continuous; sometimes it will cease for days, and the proprietor congratulates himself that the horse is getting well; the fetor, however, remains, and after a time it breaks forth again with redoubled vigour. The animal becomes daily worse, and would linger on, but the patience of the owner is exhausted; the knacker is employed to cut short the hopeless trouble and expense, and then a hasty examination is made for the cause of all this mischief. Such is a condensed description of the customary incidents, in the order in which they ensue; but of course the intelligent reader is aware that the symptoms of disease cannot be mapped down, as though they were results obtained from inorganic matter. Such symptoms always more or less vary, though upon the whole they present sufficient similarity to enable them, in every case, to be interpreted; and hence the value of practical experience, which enables the party possessing it to recognise a fact, when not fully declared. The writer cannot, to the like extent, communicate instruction; he must condense his remarks, and be content to speak a general truth; for if he descends to particulars he becomes tedious, and that which he would teach is disregarded. Of course the symptoms vary: all may not be present, yet one or more will lead the practised mind to the seat of injury. The history, however, which has been recorded, supposes the dead tooth to be located in the upper jaw: should it be situated in the lower jaw, some difference will be presented in the effect; for then the injury is not so serious. The discharge from the nostrils does not ensue, but the inferior maxillary bone enlarges, and the breath becomes offensive. The swelling of the bone takes place immediately under the tooth which has ceased to be a part of the living frame; and at this point also an abscess forms; this bursts, and discharges an unhealthy matter: unlike ordinary abscesses, however, which, when they have thrown out their contents, close, this, notwithstanding that the orifice is dependent, exhibits no disposition to heal up: a thin stinking liquid continuously issues from the opening, which becomes hard around its edges, and the hair about which sticks out, looking coarse and ragged. Such outward and visible signs are hardly to be misunderstood; and attention being directed to the mouth, the examination of the teeth will confirm them. From one jaw will be felt a molar projecting far above the level of the rest, and in a like degree will the opposing tooth in the other jaw be found depressed--worn down actually to the gum. All is now clear; and the question is, what shall be done? In the first place the condition of the mouth has certainly deranged the digestive organs, and, where there is room for choice, no operation, however simple or apparently safe, should be undertaken while the stomach is out of order. The seat of the disease is known, but the general health is first attended to; and when that has been in some measure re-established, the great object of the surgeon is fit to be accomplished. The question is, which of the teeth are to be interfered with? One is diseased or dead, and there can be no doubt that the diseased tooth should be removed. That which is unnaturally long, obviously indicates that its power of growth is retained; and though hypertrophy is an abnormal action, teeth are not parts liable to that species of affection. The one which by its growth indicates vitality, therefore displays no symptom of disease; but the tooth that is reduced to the level of the gums, tells us that its power of self-preservation has ceased, and that its vitality is gone. If that tooth be felt, it will, in the majority of instances, be found loose, and therefore it can be easily extracted: the operation, however, is not then ended. Should the affected organ have occupied the upper jaw, a quantity of pus may flow freely into the mouth on its extraction, but more frequently such will not be the case: nevertheless, the discharge from the nostril, (should the case have been of long standing,) together with the softened and swollen condition of the facial bones, may convince the attendant that matter is locked up in the maxillary sinuses. Some writers speak of the antrum as the part most seriously affected; but I cannot find any thing corresponding to the antrum in the horse's head. That animal has no development of this description, and therefore it only shows ignorance to operate with a special view to opening an imaginary cavity. The maxillary sinuses are spacious cells, and freely communicate with the frontal sinuses, which are also large. These facial sinuses have but a limited and kind of valvular opening into the nasal chambers, and if pus is allowed to remain within them there is little hope of cure: therefore a means must be found for its escape. To this end the finger is employed to probe the alveolar cavity, whence the tooth was taken, and it will probably prove to be of no great depth. An instrument constructed for the purpose is now used, and with it a hole is made through the walls of the alveolar, directly into the maxillary sinus--his knowledge of anatomy teaching the operator so to direct his hand that none of the important nerves and vessels, which ramify through the parts he is penetrating into, may be injured. On the withdrawal of the instrument, pus will mostly follow, but not gush forth as from an ordinary abscess. A dependent orifice has now been established, and if the case is not a severe one, that may be sufficient: if, however, the disease is aggravated, it will be necessary to trepline the frontal and perhaps the maxillary bone, leaving in each a free space, from which a circular piece has been removed. Through the superior opening, warm water is injected; but if the stench be very offensive, a weak solution of chloride of lime or of creosote may be employed, and must be daily repeated. None of the coarse applications which some ignorant persons recommend, ought to be used. A strong solution of the sulphate of copper or of zinc, by coming in contact with a large surface of granulating mucous membrane, can hardly be expected to allay its irritability, or dispose it to take on a healthy action; and a seton, forced barbarously through the orifices made with the trephine, can only exist as a foreign agent, keeping up the action which the surgeon is desirous should terminate. Gentle means are, in every sense, the ones to be adopted. Mild tepid injections are to be employed, with the intention to wash out the accumulated pus, allay the inflammation that caused it to be secreted, and correct the diseased tendency of the part. All stronger agents are barbarous; and I have witnessed animals rendered dangerously vicious by their employment. When, however, the acute stage has past; when the inflamed and secreting surface has lost its activity, not unfrequently succeeds a dull, lethargic state, which the mild treatment, hitherto advised, will not touch: now it is that stimulating injections are beneficial; and however much reason there was in the first instance to denounce their employment, they are now indicated by the soundest principles of scientific practice. Even at this time, however, they must not be pushed too far. The constitution should be stimulated, that their effect may be aided, and their continuance necessitated for the shortest possible period. The sulphate of copper or of zinc; the acetate of copper or of zinc; the chloride of zinc or of lime; the nitrate of silver or of mercury; the black or yellow wash, in strength proportioned to the symptoms, may here be of service. It is well, however, to remember that these agents soon lose the efficacy, and the greatest benefit, therefore, is obtained when they are occasionally changed on the first sign of their potency decreasing. Still injections alone cannot be expected to effect a restoration, and, therefore, topical measures must be combined with constitutional treatment. A course of mercury may be tried, or some of the many agents, which, like balsams, peppers, and essential oils, act on the mucous system, can be administered,--never, however, relying upon any one medicine for too long a period; but, as in the previous case of injections, changing it wherever the drug appears either to have no effect, or to have lost its power over the system. By such treatment, actively employed and combined with a proper attention to exercise and diet, the case must be aggravated indeed which is beyond relief. The cure, however, we must not expect to be quick; but it will generally in the end be realized. Perseverance may be required, but barbarity will not hasten success. I object to many of the practices which the veterinary professors of the London College inculcate to their pupils; because those practices, in my opinion, being based on false principles, are needlessly severe. Of the potent solutions habitually employed at the St. Pancras School, I have spoken; but there is another practice to which I have not alluded: corks are forcibly thrust into the holes made by the trephine, under the notion that by such means the opening can be kept free, and the wound uncorked and corked up like the mouth of a bottle. Mr. Percival has spared me the trouble of exposing the folly of the idea, and the inutility of the practice. That gentleman tried the notable experiment, and found that the cork in no degree delayed the consequence it was employed to retard. The presence of a foreign body thrust into immediate connexion with a diseased surface, and violently there retained, must cause excruciating agony--promote serious irritation--and might lead to the worst possible results. The ignorance should indeed be gross, which could conjecture such a vulgar resort was capable of inducing the slightest benefit. Equally objectionable is the custom recommended by the veterinary professors, of shutting an animal up in a close stable, and causing it to inhale the fumes of chlorine gas. Chlorine is an irritant to mucous membranes. If the nasal cavities were the seat of the disease, the passage of the air being rapid through these channels, and retained for a comparatively long period in the bronchia, the supposed remedy would be far more likely to affect the lungs, than to act immediately on the part which it was intended to benefit. In respiration, however, it is not probable that even during health, any large quantity of air enters the sinuses, which, in these cases, are the seats of the disease; and when those cavities are blocked up by an abnormal secretion, none could possibly gain admittance to them. Chlorine, therefore, obviously is inoperative in the direction where its remedial agency is desired to act; and it does some injury. It violently affects the animal which requires to be soothed; causes it to endure much inconvenience and even suffering; produces quickened respiration with violent cough, and may be reasonably supposed to lay the foundation of subsequent disease. The advantages of its employment have not been demonstrated, but the results of practice rather show it to be injurious. By the members of the veterinary profession it is not generally used: gentler measures are of greater importance, and these ought, only under very peculiar circumstances, to be abandoned. There, however, yet remains to be described, the mode of proceeding when the diseased tooth is seated in the lower jaw. In that case, a sinus or canal, discharging an unhealthy matter, is present. No treatment will cause that sinus to close, while the diseased tooth is retained; and until its removal is effected, all applications designed for that end are thrown away. After the tooth has been extracted, a solution of sulphate of zinc may, with advantage, be daily injected, and constitutional measures at the same time adopted, till an altered action has been called forth, when the annoyance will quickly cease. The enlarged bone will, however, remain; and, in the majority of cases, it may be best no further to interfere with it, than by the external application of such agents as are likely to promote absorption. In such cases, however, no means are very speedily beneficial, and time must be given for their operation: but should the deformity be great, the firing iron may be employed to cause exfoliation of the part. Yet as in the removal of one blemish, it is not justifiable to create another, the violent agent must be applied after a particular manner. The integument should be first divided, and the edges of the incision drawn asunder, so as to expose the bone, which alone should be touched with the cautery. By this simple expedient the osseous structure will be destroyed; and as such structure is not highly sensitive, the suffering of the animal will be slight, while after exfoliation has taken place, the trivial cicatrix will be concealed by the hair. When caries is present, the symptoms do not materially differ from those described as indicating the death of a tooth. The disease may commence at any part of the fang or crown; but the structure which it generally first involves in the horse, is the crusta petrosa: for however far the caries had proceeded, I have usually recognised it working from this substance into the ivory. The crusta petrosa is the least osseous, and most vascular of all the structures that enter the composition of the tooth. In proportion to the vascularity, may be estimated the disposition to assume disease; and when it is further remembered that the crusta petrosa being the external, is the most exposed portion of the tooth, and that any wrenching action, or other violence, would first affect this part, the dullest comprehension will perceive why the crusta petrosa is likely to be the primary seat of caries. Enamel is not subject to caries, nor is it otherwise involved than by being deprived of its supports, and chemically acted upon by the decomposed matters with which it is in contact. The ivory, however, may, in exceptionable cases, be the original seat of the affection; and when decay has commenced, this part of the tooth is speedily diseased. When caries begins, there is only partial death of the tooth; but the portions which retain their vitality and are becoming affected, cause excruciating fits of agony. Before anything can be perceived by manipulating the molars, the animal may exhibit frequent slight fits of illness, being occasionally dull--off its feed--sluggish at its work--soon fatigued--resting the head on the manger, and displaying symptoms of transient attacks of fever. On other days the animal is lively; eats well, looks well, and works well, and is all the owner could desire. Something is evidently wrong, but as yet all is doubt: then the hay is quidded and another examination of the molars is made, when there may be detected a little roughness on some part of one of those teeth, and the mystery is explained. There may be no, or a very slight increased growth of the molar, which, in the opposing jaw, corresponds to that which is evidently carious. The carious tooth may be firmly implanted; and yet, notwithstanding the firm manner in which it is fixed in the jaw, no time ought to be lost in its removal. The operation may occupy some time, and should be conducted with proper caution if the horse be young; and I have by me a molar taken from the jaw of a colt that was rising four, in which the crusta petrosa was diseased. A wood-cut representing that tooth, is inserted at page 29; and the darker spot indicates the place where decay had commenced. During youth the fangs of the molars are of great length, consequently, any violence would be likely to do injury to the thin plates of the alveolar cavity. In old animals the fangs being shorter, greater speed may be allowable; but in every instance where the tooth is firm, judgment must be exercised. Supposing the horse to be young, the following method will be found to answer:--The precise position of the tooth having been ascertained, and the animal cast, traction, with a proper instrument, is made in the right direction. In the first attempt the force is not designed to extract the tooth; if it can be perceptibly moved or raised upward, so that the nerves and arteries of the pulp may be broken or ruptured, a great point has been gained, and the molar should be no further drawn in the first instance. The instrument should be then loosened, and another hold having been taken, a renewed effort should be made, when a little additional way may be gained. After this, a further hold should be taken, and thus adapting the grasp of the instrument to each pull, and proceeding gradually, the molar may be extracted. The operator, however, must not, in every instance, anticipate that he will be thus successful. The tooth may be perceptibly moved, but after this it may resist all subsequent attempts. The surgeon will become aware that only great force could accomplish his wishes, and he will therefore reflect whether the employment of the necessary violence might not fracture the jaw as well as extract the tooth. Something has been gained by rupturing the arteries and nerves. The pain and course of the disease has, in a degree, been checked. The molar is no longer a part of the body, but a foreign substance; and Nature, if left alone, will proceed in her own way to eject it. The course, however, that Nature, if unaided, would pursue, might be too slow to prevent evil consequences. The operator, therefore, discontinues his attempts for the present; and though some foolish persons will think slightly of him, for not at once doing the thing he desired to accomplish, he orders the animal to be let up, and led back into the stable. Many a proprietor has been so displeased by this, that he has thereupon sought other advice; and the next operator has pleasingly surprised him, by extracting, with ease, the tooth which the first wisely forbore to wrench out of the jaw. The fact is, that the time which intervened had made a material change; the molar had become loose, and he who properly refused in the first instance to drag it forth, would now, had he been permitted, have taken it out without difficulty. Indeed in every case where the operator is made conscious of great opposition from natural causes, it is better to cease all attempts for the present--to wait for a week or two, and then renew the trial; and even make a third effort, after a like pause, rather than by unjustifiable violence hazard an accident, perhaps more fatal in its consequences than the evil which it was desired should be removed. The course of the malady allows the surgeon to exercise his patience, without effort; and even if danger threatened, his principles teach him that force is never justifiable. Gentle, resolute, and collected, must such a person be at all times: the violence he seems to employ is but the proper application of his art, and the speed he appears to make is but the graceful use of the time and means at his command. Often does he to the ignorant appear to be idle, when he is only anxiously waiting for the proper time to commence his operations; and frequently is he accused of precipitation, when he knows that activity alone can crown his efforts with success. Let there then be no authority exercised over him whose painful duty it is to deal with disease. The means at his command are confessedly small, the end to be accomplished is acknowledged to be great. The labour is harrassing, the result is dubious, and any interference can but deteriorate from the success of the issue. A wise person will therefore see often, observe much, and think long, before he presumes to suggest anything to a medical practitioner, and never will a command issue from his mouth. All, however, within and about the stable, are, for the most part, in their own conceits, qualified to cure the horse; and curious are the suggestions obtrusively volunteered, and the judgments pronounced during every operation. Frequently, indeed, is the animal sacrificed by the ignorance of its anxious attendants, who, in their zeal, will often, out of their scanty wages, purchase injurious nostrums, notwithstanding a member of the Royal College of Veterinary Surgeons may be in regular attendance. Happily for the teeth, no specifics are yet declared, and the groom is therefore unwillingly obliged to be idle. The owner should also be passive, seeing that which is ordered is administered, and taking care that no charms are employed. When the tooth that was carious is in the early stage extracted, the animal is by a little constitutional treatment, afterwards quickly restored, but from time to time will require attention; for the teeth that have once been operated on, will, at intervals, ever after during the life of the horse, need the hand of the surgeon. If caries, however, is neglected, and proceeds to the last stage, cure is all but hopeless. During the death of a tooth, the symptoms are continuous. In caries, there are intermissions, seasons of uncertain duration, during which the horse appears to be free from suffering; but the effects, if not so rapid in their development, are more frequently fatal in their termination. When a tooth has lost its vitality, it becomes a foreign body, which Nature, in time, will cast out. The retention irritates the surrounding structures, but the irritation may in part be regarded as a restorative process. When caries takes place, a portion only dies, but that portion has all the injurious effect which could be attributed to the former case, and even more, for the remaining vitality in the unaffected part of the tooth, prevents Nature from resorting to that process by which she would otherwise cast off the dead matter. In consequence of this, a foreign substance is retained for a longer period, and at the same time disease is progressing. Here, therefore, is an additional cause at work, and hence the excess of effect. The arteries which nourish the pulp, and the crusta petrosa, proceed from the vessels which nurture the bone, and supply the mucous membrane of the sinuses with the means of secretion. The same, likewise, may be stated of the nerves going to the tooth, and though through these last the constitution is affected, it is mainly through the agency of the blood vessels, that the sinuses become diseased. Hence the necessity for decision, and the need of judgment, in the application of the remedy. To enforce the foregoing remarks, and convey to the reader a slight idea of the consequences which ensue from a carious tooth, the accompanying wood-cut is introduced. The specimen selected for illustration, does not exhibit a rare or extraordinary proof of the results of this species of disease.