Part 37

(2) In inflammations due to local irritants of a noninfective kind a careful examination will usually reveal their presence, and the first step must be their removal with a pair of blunt forceps or the point of a lead pencil. Subsequent treatment will be in the main the local treatment advised above.

(3) In case of infective inflammation there will often be found a prick or tear by which the septic matter has entered, and in such case the inflammation will for a time be concentrated at that point. A round or conical swelling around an insect bite is especially characteristic. A snake bite is marked by the double prick made by the two teeth and by the violent and rapidly spreading inflammation. Erysipelas is attended with much swelling, extending beyond the lids and causing the mucous membrane to protrude beyond the edge of the eyelid (chemosis). This is characterized by a bright, uniform, rosy red, disappearing on pressure, or later by a dark, livid hue, but with less branching redness than in noninfecting inflammation and less of the dark, dusky, brownish or yellowish tint of anthrax. Little vesicles may appear on the skin, and pus may be found without any distinct limiting membrane, as in abscess. It is early attended with high fever and marked general weakness and inappetence. Anthrax of the lids is marked by a firm swelling, surmounted by a blister, with bloody serous contents, which tends to burst and dry up into a slough, while the surrounding parts become involved in the same way. Or it may show as a diffuse, dropsical swelling, with less of the hard, central sloughing nodule, but, like that, tending to spread quickly. In both cases alike the mucous membrane and the skin, if white, assumes a dusky-brown or yellowish-brown hue, which is largely characteristic. This may pass into a black color by reason of extravasation of blood. Great constitutional disturbance appears early, with much prostration and weakness and generalized anthrax symptoms.

Treatment.—The treatment will vary according to the severity. Insect bites may be touched with a solution of equal parts of glycerin and aqua ammonia, or a 10 per cent solution of carbolic acid in water. Snake bites may be bathed with aqua ammonia, and the same agent given in doses of 2 teaspoonfuls in a quart of water, or alcohol may be given in pint or quart doses, according to the size of the animal. In erysipelas the skin may be painted with tincture of chlorid of iron, or with a solution of 20 grains of iodin in an ounce of carbolic acid, and one-half an ounce of tincture of chlorid of iron may be given thrice daily in a bottle of water. In anthrax the swelling should be painted with tincture of iodin, or of the mixture of iodin and carbolic acid, and if very threatening it may have the tincture of iodin injected into the swelling with a hypodermic syringe, or the hard mass may be freely incised to its depth with a sharp lancet and the lotion applied to the exposed tissues. Internally, iodid of potassium may be given in doses of 2 drams thrice a day, or tincture of the chlorid of iron every four hours.

STY, OR FURUNCLE (BOIL) OF THE EYELID.

This is an inflammation of limited extent, advancing to the formation of matter and the sloughing out of a small mass of the natural tissue of the eyelid. It forms a firm, rounded swelling, usually near the margin of the lid, which suppurates and bursts in four or five days. Its course may be hastened by a poultice of camomile flowers, to which have been added a few drops of carbolic acid, the whole applied in a very thin muslin bag. If the swelling is slow to open after having become yellowish white, it may be opened by a lancet, the incision being made at right angles to the margin of the lid.

ENTROPION AND ECTROPION, OR INVERSION AND EVERSION OF THE EYELID.

These are respectively caused by wounds, sloughs, ulcers, or other causes of loss of substance of the mucous membrane on the inside of the lid and of the skin on the outside; also of tumors, skin diseases, or paralysis which leads to displacement of the margin of the eyelid. As a rule, they require a surgical operation, with removal of an elliptical portion of the mucous membrane or skin, as the case may be, but which requires the skilled and delicate hand of the surgeon.

TRICHIASIS.

This consists in the turning in of the eyelashes so as to irritate the front of the eye. If a single eyelash, it may be snipped off with scissors close to the margin of the eyelid or pulled out by the root with a pair of flat-bladed forceps. If the divergent lashes are more numerous, the treatment may be as for entropion, by excising an elliptical portion of skin opposite the offending lashes and stitching the edges together, so as to draw outward the margin of the lid at that point.

WARTS AND OTHER TUMORS OF THE EYELIDS.

The eyelids form a favorite site for tumors, and above all, warts, which consist in a simple diseased overgrowth (hypertrophy) of the surface layers of the skin. If small, they may be snipped off with scissors or tied around the neck with a stout, waxed thread and left to drop off, the destruction being completed, if necessary, by the daily application of a piece of sulphate of copper (blue vitriol), until any unhealthy material has been removed. If more widely spread, the wart may still be clipped off with curved scissors or knife, and the caustic thoroughly applied day by day.

A bleeding wart, or erectile tumor, is more liable to bleed, and is best removed by constricting its neck with the waxed cord or rubber band, or if too broad it may be transfixed through its base by a needle armed with a double thread, which is then to be cut in two and tied around the two portions of the neck of the tumor. If still broader, the armed needle may be carried through the base of the tumor at regular intervals, so that the whole may be tied in moderately sized sections.

In gray and in white horses black, pigmentary tumors (melanotic) are common on the black portions of skin, such as the eyelids, and are to be removed by scissors or knife, according to their size. In the horse they do not usually tend to recur when thoroughly removed, but at times they prove cancerous (as is the rule in man), and then they tend to reappear in the same site or in internal organs with, it may be, fatal effect.

Encysted, honeylike (melicerous), sebaceous, and fibrous tumors of the lids all require removal with the knife.

TORN EYELIDS OR WOUNDS OF EYELIDS.

The eyelids are torn by attacks with horns of cattle, or with the teeth, or by getting caught on nails in stall, rack, or manger, on the point of stumps, fences, or fence rails, on the barbs of wire fences, and on other pointed bodies. The edges should be brought together as promptly as possible, so as to effect union without the formation of matter, puckering of the skin, and unsightly distortions. Great care is necessary to bring the two edges together evenly without twisting or puckering. The simplest mode of holding them together is by a series of sharp pins passed through the lips of the wound at intervals of not more than a third of an inch, and held together by a thread twisted around each pin in the form of the figure 8, and carried obliquely from pin to pin in two directions, so as to prevent gaping of the wound in the intervals. The points of the pins may then be cut off with scissors, and the wound may be wet twice a day with a weak solution of carbolic acid.

TUMOR OF THE HAW, OR CARIES OF THE CARTILAGE.

Though cruelly excised for alleged "hooks," when itself perfectly healthy, in the various diseases which lead to retraction of the eye into its socket, the haw may, like other bodily structures, be itself the seat of actual disease. The pigmentary, black tumors of white horses and soft (encephaloid) cancer may attack this part primarily or extend to it from the eyeball or eyelids; hairs have been found growing from its surface, and the mucous membrane covering it becomes inflamed in common with that covering the front of the eye. These inflammations are but a phase of the inflammation of the external structures of the eye, and demand no particular notice nor special treatment. The tumors lead to such irregular enlargement and distortion of the haw that the condition is not to be confounded with the simple projection of the healthy structure over the eye when the lids are pushed apart with the finger and thumb, and the same remark applies to the ulceration, or caries, of the cartilage. In the latter case, besides the swelling and distortion of the haw, there is this peculiarity, that in the midst of the red inflamed mass there appears a white line or mass formed by the exposed edge of the ulcerating cartilage. The animal having been thrown and properly fixed, an assistant holds the eyelids apart while the operator seizes the haw with forceps or hook and carefully dissects it out with blunt-pointed scissors. The eye is then covered with a cloth, kept wet with an eyewash, as for external ophthalmia.

OBSTRUCTION OF THE LACRIMAL APPARATUS, OR WATERING EYE.

The escape of tears on the side of the cheek is a symptom of external inflammation of the eye, but it may also occur from any disease of the lacrimal apparatus which interferes with the normal progress of the tears to the nose; hence, in all cases when this symptom is not attended with special redness or swelling of the eyelids, it is well to examine the lacrimal apparatus. In some instances the orifice of the lacrimal duct on the floor of the nasal chamber and close to its anterior outlet will be found blocked by a portion of dry mucopurulent matter, on the removal of which tears may begin to escape. This implies an inflammation of the canal, which may be helped by occasional sponging out of the nose with warm water, and the application of the same on the face. Another remedy is to feed warm mashes of wheat bran from a nosebag, so that the relaxing effects of the water vapor may be secured.

The two lacrimal openings, situated at the inner angle of the eye, may fail to admit the tears by reason of their deviation outward in connection with the eversion of the lower lid or by reason of their constriction in inflammation of the mucous membrane. The lacrimal sac, into which the lacrimal ducts open, may fail to discharge its contents by reason of constriction or closure of the duct leading to the nose, and it then forms a rounded swelling beneath the inner angle of the eye. The duct leading from the sac to the nose may be compressed or obliterated by fractures of the bones of the face, and in disease of these bones (osteosarcoma, so-called osteoporosis, diseased teeth, glanders of the nasal sinuses, abscess of the same cavities).

The narrowed or obstructed ducts may be made pervious by a fine, silver probe passed down to the lacrimal sac, and any existing inflammation of the passages may be counteracted by the use of steaming mashes of wheat bran, by fomentations or wet cloths over the face, and even by the use of astringent eyewashes and the injection of similar liquids into the lacrimal canal from its nasal opening. The ordinary eyewash may be used for this purpose, or it may be injected after dilution to half its strength. The fractures and diseases of the bones and teeth must be treated according to their special demands when, if the canal is still left pervious, it may be again rendered useful.

EXTERNAL OPHTHALMIA, OR CONJUNCTIVITIS.

In inflammation of the outer parts of the eyeball the exposed vascular and sensitive mucous membrane (conjunctiva) which covers the ball, the eyelids, the haw, and the lacrimal apparatus, is usually the most deeply involved, yet adjacent parts are more or less implicated, and when disease is concentrated on these contiguous parts it constitutes a phase of external opththalmia which demands a special notice. These have accordingly been already treated of.

Causes.—The causes of external opththalmia are mainly those that act locally—blows with whips, clubs, and twigs, the presence of foreign bodies, like hayseed, chaff, dust, lime, sand, snuff, pollen of plants, flies attracted by the brilliancy of the eye, wounds of the bridle, the migration of the scabies (mange) insect into the eye, smoke, ammonia arising from the excretions, irritant emanations from drying marshes, etc. Road dust containing infecting microbes is a common factor. A very dry air is alleged to act injuriously by drying the eye as well as by favoring the production of irritant dust; the undue exposure to bright sunshine through a window in front of the stall, or to the reflection from snow or water, also is undoubtedly injurious. The unprotected exposure of the eyes to sunshine through the use of a very short overdraw check is to be condemned, and the keeping of the horse in a very dark stall, from which it is habitually led into the glare of full sunlight, intensified by reflection from snow or white limestone, must be set down among the locally acting causes. Exposure to cold and wet, to wet and snow storms, to cold drafts and wet lairs must also be accepted as causes of conjunctivitis, the general disorder which they produce affecting the eye, if that happens to be the weakest and most susceptible organ of the body, or if it has been subjected to any special local injury, like dust, irritant gases, or excess of light. Again, external opththalmia is a constant concomitant of inflammation of the contiguous and continuous mucous membranes, as those of the nose and throat—hence the red, watery eyes that attend on nasal catarrh, sore throat, influenza, strangles, nasal glanders, and the like. In such cases, however, the affection of the eye is subsidiary and is manifestly overshadowed by the primary and predominating disease.

Symptoms.—The symptoms are watering of the eye, swollen lids, redness of the mucous membrane exposed by the separation of the lids—it may be a mere pink blush with more or less branching redness, or it may be a deep, dark red, as from effusion of blood—and a bluish opacity of the cornea, which is normally clear and translucent. Except when resulting from wounds and actual extravasation of blood, however, the redness is seen to be superficial, and if the opacity is confined to the edges, and does not involve the entire cornea, the aqueous humor behind is seen to be still clear and limpid. The fever is always less severe than in internal ophthalmia, and runs high only in the worst cases. The eyelids may be kept closed, the eyeball retracted, and the haw protruded over one-third or one-half of the ball, but this is due to the pain only and not to any excessive sensibility to light, as shown by the comparatively widely dilated pupil. In internal ophthalmia, on the contrary, the narrow, contracted pupil is the measure of the pain caused by the falling of light on the inflamed and sensitive optic nerve (retina) and choroid.

If the affection has resulted from a wound of the cornea, not only is that the point of greatest opacity, forming a white speck or fleecy cloud, but too often blood vessels begin to extend from the adjacent vascular covering of the eye (sclerotic) to the white spot, and that portion of the cornea is rendered permanently opaque. Again, if the wound has been severe, though still short of cutting into the anterior layers of the cornea, the injury may lead to ulceration that may penetrate more or less deeply and leave a breach in the tissue which, if filled up at all, is repaired by opaque fibrous tissue in place of the transparent cellular structure. Pus may form, and the cornea assumes a yellowish tinge and bursts, giving rise to a deep sore which is liable to extend as an ulcer, and may be in its turn followed by bulging of the cornea at that point (staphyloma). This inflammation of the conjunctiva may be simply catarrhal, with profuse mucopurulent discharge; it may be granular, the surface being covered with minute reddish elevations, or it may become the seat of a false membrane (diphtheria).

Treatment.—In treating external ophthalmia the first object is the removal of the cause. Remove any dust, chaff, thorn, or other foreign body from the conjunctiva, purify the stable from all sources of ammoniacal or other irritant gas; keep the horse from dusty roads, and, above all, from the proximity of a leading wagon and its attendant cloud of dust; remove from pasture and feed from a rack which is neither so high as to drop seeds, etc., into the eyes nor so low as to favor the accumulation of blood in the head; avoid equally excess of light from a sunny window in front of the stall and excess of darkness from the absence of windows; preserve from cold drafts and rains and wet bedding, and apply curative measures for inflammation of the adjacent mucous membranes or skin. If the irritant has been of a caustic nature, remove any remnant of it by persistent bathing with tepid water and a soft sponge, or with water mixed with white of egg, or a glass filled with the liquid may be inverted over the eye so that its contents may dilute and remove the irritant. If the suffering is very severe, a lotion with a few grains of extract of belladonna or of morphia in an ounce of water may be applied, or, if it is available, a few drops of 4 per cent solution of cocaine may be instilled into the eye.

In strong, vigorous patients benefit will usually be obtained from a laxative, such as 2 tablespoonfuls of Glauber's salt daily, and if the fever runs high from a daily dose of half an ounce of saltpeter. As local applications, astringent solutions are usually the best, as 30 grains of borax or of sulphate of zinc in a quart of water, to be applied constantly on a cloth, as advised under "Inflammation of the eyelids." In the absence of anything better, cold water may serve every purpose. Above all, adhesive and oily agents (molasses, sugar, fats) are to be avoided, as only adding to the irritation. By way of suggesting agents that may be used with good effect, salt and sulphate of soda may be named, in solutions double the strength of sulphate of zinc, or 7 grains of nitrate of silver may be added to a quart of distilled water, and will be found especially applicable in granular conjunctivitis, diphtheria, or commencing ulceration. A cantharides blister (1 part of Spanish fly to 4 parts lard) may be rubbed on the side of the face 3 inches below the eye, and washed off next morning with soapsuds and oiled daily till the scabs are dropped.

WHITE SPECKS AND CLOUDINESS OF THE CORNEA.

As a result of external ophthalmia, opaque specks, clouds, or haziness are too often left on the cornea and require for their removal that they be daily touched with a soft feather dipped in a solution of 3 grains nitrate of silver in 1 ounce distilled water. This should be applied until all inflammation has subsided, and until its contact is comparatively painless. It is rarely successful with an old, thick scar following an ulcer, nor with an opacity having red blood vessels running across it.

ULCERS OF THE CORNEA.

These may be treated with nitrate of silver lotion of twice the strength used for opacities. Powdered gentian, one-half ounce, and sulphate of iron, one-fourth ounce, daily, may improve the general health and increase the reparatory power.

INTERNAL OPHTHALMIA (IRITIS, CHOROIDITIS, AND RETINITIS).

Although inflammations of the iris, choroid, and retina—the inner, vascular, and nervous coats of the eye—occur to a certain extent independently of each other, yet one usually supervenes upon the other, and, as the symptoms are thus made to coincide, it will be best for our present purposes to treat the three as one disease.

Causes.—The causes of internal ophthalmia are largely those of the external form only, acting with greater intensity or on a more susceptible eye. Severe blows, bruises, punctures, etc., of the eye, the penetration of foreign bodies into the eye (thorns, splinters of iron, etc.), sudden transition from a dark stall to bright sunshine, to the glare of snow or water, constant glare from a sunny window, abuse of the overdraw checkrein, vivid lightning flashes, drafts of cold, damp air; above all, when the animal is perspiring, exposure in cold rain or snowstorms, swimming cold rivers; also certain general diseases like rheumatism, arthritis, influenza, and disorders of the digestive organs, may become complicated by this affection. From the close relation between the brain and eye—alike in the blood vessels and nerves—disorders of the first lead to affection of the second, and the same remark applies to the persistent irritation to which the jaws are subjected in the course of dentition. So potent is the last agency that we dread a recurrence of ophthalmia so long as dentition is incomplete, and hope for immunity if the animal completes its dentition without any permanent structural change in the eye.