Causes. These may be classed as mechanical, chemical, microbian and other irritants. In the horse it is often due to the reckless administration of irritant liquids as remedies. Owing to the length of the soft palate the horse can refuse to swallow any liquid as long as he chooses, and some of the worst cases of stomatitis I have seen resulted from the retention in the mouth of caustic alkaline liquids given under the name of “weak lye.” Strong acids and caustic salts dissolved in too little water or other excipient, or suspended in liquids in which they cannot dissolve, or made into boluses which are crushed between the teeth are not infrequent conditions. Too hot mashes given to a hungry horse is another cause of this trouble. Fermented or decomposed food is often most irritating. Coachmen will sometimes induce it by attaching to the bit bags of spicy or irritant agents, to cause frothing and make the animal appear spirited.
Fungi in fodders are among the common causes. The rust of wheat (puccinia graminis), the caries of wheat (tilletia caries), the blight (erysiphe communis), ergot (claviceps purpurea), the fungus of rape (polydesmus excitiosus) and the moulds (penicillium and puccinia) have all been noticed to coincide with stomatitis, and charged with producing it. On the other hand, at given times, one or other of these cryptogams has been present extensively in the fodder without any visible resultant stomatitis. The apparent paradox may be explained by the fact that these fungi vary greatly in the irritant or harmless nature of their products according to the conditions under which they have grown, and the stage of their development at which they were secured and preserved. Ergot notoriously differs in strength in different years, on different soils, under various degrees of sunshine, shade, cloud, fog, etc. In different States in the Mississippi valley it is not uncommon to find stomatitis in horses in winter, fed on ergoted hay, while cattle devouring the same fodder have dry gangrene of feet, tail and ears. Yet in other seasons the ergot fails to produce these lesions. Rank grown, watery vegetation, especially if it contains an excess of chlorophyll is liable to cause stomatitis. Red and white clover, trefoil, hybrid and purple clover, and alfalfa have all acted more or less in this way, though in many cases, the food has become musty or attacked by bacterial ferments. Some of the strongly aromatic plants, and those containing acrid principles (cicuta virosa, œnanthe crocata, mustard, etc.) cause buccal inflammation and salivation.
The irritation in many such cases is not due to one agent only, the vegetable or other irritant may be the starting point, acting but as a temporary irritant, the action of which is supplemented and aggravated by the subsequent attacks of bacterial ferments on the inflamed, weakened or abraded tissues. The bacteria present in the mouth, food or water would have had no effect whatever upon the healthy mucosa, while they make serious inroads on the diseased. On the other hand the vegetable, mechanical or chemical irritant would have had but a transient effect, but for the supplementary action of the bacteria.
In horses that have the bad habit of retaining masses of half masticated food in the cheeks the growth of cryptogams is greatly enhanced and such food often becomes violently irritating.
Among other mechanical causes may be named pointed or barbed hairs or spines (barley awns, spikes, thorns, etc.) which, lodging in a gland orifice, or in a wound of the gum or mucosa, form a source of irritation or a centre for bacterial growth and abscess.
Again, irritants of animal origin must be named. These are not taken by choice, but when lodged in fodder, or in the pastures they are taken in inadvertently with the food. In this way poisonous insects, and especially hairy caterpillars, cantharides, potato bugs, etc., gain access to the mouth.
It must not be overlooked that stomatitis occurs as an extension, sympathetic affection or sequel of diseases of other organs. Gastritis is usually attended by redness and congestive tenderness of the tongue, especially of the tip and margins, and other parts of the buccal mucosa, notably the palate just back of the incisors, are often involved. In other cases it appears as a complication of pharyngitis, laryngitis, of affections of the lower air passages, of the teeth and periodontal membrane or of the salivary glands.
It appears also in a specific form in certain fevers, as in horsepox, pustulous stomatitis, aphthous fever and even in strangles. Mercurial stomatitis, rarely seen at the present time, is one of the worst forms of the disease, and like the infectious forms will be treated separately.
Lesions and Symptoms. At the outset and in the slighter forms of congestion there is merely heat and dryness of the buccal mucosa. Redness may show on the thinner and more delicate portions of the membrane, as under the tongue, on the frænum, and on the sublingual crest. But elsewhere it is hidden by the thickness of the epithelium, and the manifestations are merely those of suppressed secretion with local hyperthermia.
As the congestion is increased there is seen, even at this early stage, a slight thickening or tumefaction of the mucosa, especially on the gums, lips, the sublingual area, the orifices of the salivary glands, and the palate back of the upper incisors. On the dorsum of the tongue, the cheeks and lips, generally the lack of loose connective tissue tends to prevent the swelling.
With the advance of the inflammation the redness of the mucosa extends, at first in points and circumscribed patches, and later over the entire surface. The epithelium drying and degenerating in its surface layers forms with the mucus a sticky gummy film on the surface, which, mingling with decomposing alimentary matters gives out a heavy, offensive or even fœtid odor.
The different parts of the mouth are now tender to the touch, and this, with the fœtor and even bitterness of the bacterial products combine with the general systemic disturbance in impairing or abolishing appetite. In any case mastication becomes slow and infrequent, and morsels of food are the more likely to be retained, to aggravate the local condition by their decomposition.
The dry stage is followed by the period of hypersecretion, and in this the salivary glands take a prominent part, so that ptyalism (slobbering) becomes the most marked feature of the disease. The saliva mixed with the increasing secretion of mucus and the abundance of proliferating and shedding epithelium, escapes from the lips and falls in stringy masses in the manger and front of the stall. When there is much motion of the jaws and tongue it accumulates as a froth around the lips.
A careful examination of the mucosa will sometimes detect slight conical elevations with red areolæ, representing the tumefied orifices of the obstructed mucous follicles, and later these may show as minute erosions. Even vesicles have been noticed (Weber, Dieckerhoff, Kosters), but when these are present one should carefully exclude the specific stomatites such as horsepox, contagious pustular stomatitis, aphthous fever, etc.
Erosions of the mucosa and desquamation of the epithelium have been noticed in horses fed on purple (hybrid) clover, buckwheat or ergot, and in some of these cases the inflammation has extended (in white faces especially) to the skin of the face, the mucosa of the nose, and the adjacent glands, and as complications icterus, constipation, colics, polyuria, albuminuria and paresis of the hind limbs have been observed. These latter are common symptoms of cryptogamic poisoning.
Prognosis. In uncomplicated cases the disease is not a grave one, lasting only during the continued application of the local irritant, and recovering more or less speedily when that has been removed. Complications are dangerous only when due to some specific disease poison (glanders, actinomycosis, strangles, etc.), and even poisoning by the usual cryptogams of leafy or musty plants is rarely persistent in its effects.
Treatment. This resolves itself into the removal of the irritant cause and the soothing of the irritation. When the cause has been definitely ascertained the first step is easy.
In the direction of soothing treatment, a careful selection of diet stands first. Fibrous hay and even hard oats, barley or corn may have to be withheld, and green food, or better still, bran mashes, gruels, pulped roots or fruits allowed. Scalded hay or oats, ensilage, sliced roots, or ground feed may often be taken readily when the same aliments in their natural condition would be rejected or eaten sparingly.
Medicinal treatment may often be given in the drinking water which should always be allowed in abundance, pure and clean. In the way of medication chlorate of potash, not to exceed one-half to one ounce per day according to the size of the animal, may be added, together with an antiseptic (carbolic acid, borax, permanganate of potash, common salt, naphthol, creolin, hyposulphite of soda). In case of severe swelling, a cap made to fit the head with strips wet in alum and vinegar or other astringent solution maintained against the intermaxillary space may be desirable. Support for the tongue may be necessary as mentioned under glossitis.
In case of complications on the side of the bowels, liver or kidneys, laxatives, diuretics and antiseptic agents may be called for.
Dense resistant mucosa protective: Affection usually circumscribed. Action of violent irritants, and toxins of specific fevers. Mechanical irritants. Symptoms: Salivation; congestion; eruptions; erosions; ergot; acrid vegetables; caustics. Treatment: Astringents; antiseptics; refrigerants; derivatives; tonics. Removal of foreign bodies. Lesions and symptoms in sheep.
The mouth of the ox as Cadeae well says has a cuticular epithelium too thick and resistant to be easily attacked by microbes. It follows that infected inflammations are far more frequently circumscribed than in the thinner and softer buccal mucosa of the horse. The more general buccal inflammations come more particularly from the use of food that is too hot or that contains strongly irritant agents. The thickness of the buccal epithelium however, is no barrier to the local action of poisons operating from within as in rinderpest, or aphthous fever, or in malignant catarrh, nor is it an insuperable barrier to the local planting of the germs of cow pox, anthrax, actinomycosis, or cryptogamic aphtha (muguet). The wounds inflicted by fibrous food make infection atria for such germs, hence the great liability to such local inflammations, in winter when the animals are on dry feeding. For the same reason, perhaps, the prominent portions of the buccal mucosa,—the papillæ—are sometimes irritated themselves while serving as protectors for the general mucous surface, and hence they become specially involved in inflammation, which constituted the “barbs” of the old farriers. Utz records a buccal inflammation occurring in herds fed on green trefoil, first cutting, showing that even in cattle this agent may determine a general stomatitis.
Symptoms. These do not differ from those of the horse, and resemble, though often in a milder form, the buccal manifestations of aphthous fever. There is the difficulty of mastication and indisposition to take in fibrous aliment, the drivelling of saliva from the mouth, or its accumulation in froth around the lips, the frequent movement of the tongue and jaws, and the congestive redness, papular eruption, vesication, or even erosion of the affected mucous membrane. It is always necessary to guard against confounding the simple stomatitis, and the slighter infected inflammations, from the more violent infections above referred to. The special diagnostic symptoms must be found under the respective headings. The aphthous fever is not to be expected in American herds, but the stomatitis which is associated with ergot in the food is met more particularly in winter and spring, and must not be confounded with the specific disease, on the one hand nor with the simpler forms of buccal inflammation on the other. In the case of ergoted fodder the signs of ergotism in other situations will be found, in the affected animals, such for example as necrotic sloughs and sores around the top of the hoof, sloughing of the hoof or of one or more digits, or of the metatarsus, of the tip of the tail or ear; abortions, convulsions, delirium, lethargy or paralysis. If not seen in the same animals some of these forms may be observed in other members of the herd. Then the buccal lesions are in themselves characteristic: soft, whitish, raised patches of the epithelium (rarely blisters) are followed by desquamation and exposure of the red, vascular surface beneath, and this tends to persist if the ergoted fodder is persisted in.
Treatment. Simple stomatitis of the ox generally tends to spontaneous and early recovery. The simplest astringent and antiseptic treatment is usually sufficient to bring about a healthy action. Borax given in the drinking water, not to exceed four ounces per day, or the same amount mixed with syrup or honey and smeared occasionally on the tongue, or hyposulphite or sulphite of soda, or weak solutions of carbolic acid will usually suffice, after the irritant cause has been removed. Vinegar, or highly diluted mineral acids may be used but are somewhat hurtful to the teeth. Decoctions of blackberry bark or solutions of other vegetable astringents may be used as alternatives. When there is evidence of irritant matters in the stomach or bowels, a saline laxative will be advisable to be followed by vegetable bitters or other tonics. Thorns and other foreign bodies imbedded in the tongue or other part of the mouth must be discovered and removed.
The more delicate buccal mucosa in these animals would render them more subject to inflammations, but this is more than counterbalanced by the mode of prehension of aliments, not by the tongue, but by the delicately sensitive lips, and further by the daintiness and care with which these animals select their food. The treatment would not differ materially from that prescribed for the ox.
Causes: burns; spiced food; bones; sepsis; ferments; pin caterpillar; dental and gastric troubles. Symptoms: careful prehension and mastication; congestion; swelling; eruption; erosion; furred tongue; stringy salivation; fœtor; swelling of lips, cheeks, intermaxillary space, and pharynx. Treatment: demulcent foods; antiseptics; derivatives; tonics; care of teeth and gums.
Causes. Hot food is a common cause in hungry dogs. Spiced food in house dogs fed scraps from the table tend to congestion of mouth and stomach alike. Irritation through wounds with bones, especially in old dogs with failing teeth, and in exceptional cases the impaction of a bone between the right and left upper molars are additional causes. Putrid meat must also be recognized as a factor, the septic microbes seizing upon the wounds and spreading from this as an infecting centre. Lactic acid and other irritant products developed through fermentation of particles of food retained about the gums and cheeks soften the epithelium and irritate the sub-epithelial tissue, causing congestion. Megnin draws attention to the fact that the pin caterpillar (bombyx pinivora) found on the stalks of couch grass (Triticum repeus) produces buccal irritation when chewed and swallowed to induce vomiting. As in other animals more or less buccal congestion attends on gastric congestion and inflammation. Dental troubles are often sufficient causes.
Symptoms. The animal becomes dainty with regard to his food, picking up the smaller or softer pieces and rejecting the larger or harder. Mastication is painful and selection is made of moist or soft articles which can be swallowed without chewing or insalivation. The mouth is red and hot, and at times the mucous membrane eroded, or blistered, the lesions concentrating especially on the gums and around the borders of the tongue. The dorsum of the tongue is furred, whitish, yellowish or brownish. Saliva collects in the mouth and escapes in filmy strings from its commissures, and the odor of the mouth becomes increasingly foul. Swelling of the lips, cheeks or intermaxillary space marks the worst cases.
Treatment. Withdraw all irritant and offensive aliments. Give soups, mushes, scraped or pounded lean meat in small quantities, washing out the mouth after each meal with a 20 per cent. solution of permanganate of potash or borax or a two per cent. solution of carbolic acid. Cadeac advises against chlorate of potash on account of its known tendency to bring about hæmoglobinæmia in dogs. A laxative and bitters may be called for in case of gastritis or indigestion, and any morbid condition of the teeth must be attended to. Decayed teeth may be removed. Tartar especially must be cleaned off by the aid of a small wooden or even a steel spud and a hard brush with chalk will be useful. A weak solution of hydrochloric acid is usually employed to loosen the tartar, but this is injurious to the structure of the teeth and had best be avoided if possible. Tincture of myrrh is especially valuable both as a gum-tonic and as a deodorant and antiseptic. This may be rubbed on the irritated gums as often as the mouth is washed.