By glossitis is understood an inflamed condition of the substance of the tongue. It is a disease of seldom occurrence in the horse and usually attended with some danger, not only on account of its immediate effects, but also in consequence of its liability to leave behind chronic impairment of the function of the organ, with attendant difficulties of mastication and deglutition or swallowing.
With rare exceptions inflammation of the tongue has its origin in some form of direct irritation applied to it from without. Although so favourably situated and guarded it is nevertheless at times exposed to mechanical injury. The reckless use of too severe bits, splinters of wood, nails, and other foreign substances contained in the food, bottles broken in the act of drenching, forcible pulling and tearing the organ in the administration of balls and other operations are now and again accountable for the disease. The most common, but rarely serious, injury to the tongue is that inflicted by the edges of the molar teeth, or, as they are termed, "grinders", which in old horses become very sharp and irregular as the result of wear. A similar injury may befall young animals when shedding their suckling teeth. It does not follow that general inflammation of the tongue should necessarily result from any of these accidents. Were it so the disease would be of common occurrence. When, however, the wounds so inflicted become "poisoned", i.e. inoculated by decomposing organic matter - as likely occurred in the historic Orme case, - then to the primary injury is added a septic or putrid condition resulting in diffused inflammation of the entire organ. In some cases the sting of a bee or a wasp may be the inducing cause, as may also chemical and corrosive substances, accidentally or designedly given.
The tongue is more or less enlarged sometimes throughout its entire substance, and may protrude from the mouth for a considerable distance. In this state it is hard, tense, and painful to the touch. At first red in colour, it soon becomes of a dark purple hue as the teeth close upon it and impede circulation. Thick ropy saliva, having an offensive odour, falls from the angles of the mouth, the head is poked out, and the face wears an anxious and hideous expression.
In very acute cases the throat and neighbouring glands become swollen, as the result of which the breathing is rendered difficult and noisy, even to danger of suffocation. The constitutional disturbance will be in proportion to the severity of the attack. The enlarged and paralysed state of the tongue renders feeding and drinking impossible, save in the milder forms of the disease.
Where the disease is protracted, abscesses may form in the substance of the organ, or the surface may become eroded and covered with sores.
When the case is recognized in its first stage a dose of physic should be given at once, either as a ball or draught, while it is still practicable. It is dangerous, however, to attempt this when the tongue has become much enlarged or torn, but it may be possible to induce the animal to take an aperient dose of Epsom-salts dissolved in the drinking-water or mixed with a sloppy mash. Prompt application of mustard or turpentine liniment to the sides of the throat and between the jaws will assist in checking the progress of the disease; and relief to engorged vessels and swollen tissues may be afforded by scarification, i.e. piercing the organ in several places with the point of a lancet or sharp penknife. "When this operation is rendered necessary, care should be taken that the mouth is first washed out with antiseptic solution, and that the instrument employed is clean, or the mischief may be seriously increased.
The mouth should now be syringed out for ten minutes with warm water containing a little nitrate or chlorate of potash. After the lapse of an hour ice-cold water should be substituted for warm, and the injections should be repeated for several minutes four or five times a day. If nourishment cannot be taken by the mouth, it must be given per rectum in the form of fine oatmeal gruel and beef-tea, or raw eggs and milk.
Where suffocation threatens, an opening will require to be made in the wind-pipe. This procedure, as well as the one already referred to, calls for skill and judgment, and should be entrusted to a qualified veterinarian.
After the inflammation has subsided, the tongue will continue to be stiff and sore for some time. When feeding becomes possible, therefore, the diet should be of a soft and soothing character. Warm, sloppy mashes, well boiled roots, and steamed chaff are the most suitable fare until the tongue has recovered its normal condition.
In all cases a careful inspection of the tongue and teeth should be made at the outset for causes indicated above. Foreign agents, if found to exist, will require to be removed, and any dental disorder corrected by suitable means. (See "Diseases of Teeth".)