Part 68

The bacillus diphtheriæ avium is 0.8 to 1.5μ long, by 0.8 to 1.2μ broad. The ends are oval so that short specimens seem round. In bouillon cultures they form chains or clumps. They stain in aniline dyes, most deeply at the poles. Are not stained by Gram’s method. They are non-motile, ærobic, grow in agar, and alkaline bouillon, but render the latter acid in one or two days. Do not grow on peptone gelatine, nor produce gas with sugars. Are killed in 5 minutes at 58° C. (137° F.). Are killed by dryness in 24 hours, by sulphuric acid (0.25 ∶ 100) in 10 minutes, by lime water in 1 minute, and by sulphur fumes.

Pathogenesis. Eight rabbits inoculated subcutaneously with 0.1 cc. of the bouillon culture died in 18 to 36 hours. Of several white and gray mice inoculated only one died. Inoculations of mature hens subcutem and on the nose had no effect. Inoculation of a six weeks old chicken caused death in 4 days with bacilli in the liver and blood (Moore). Inoculation of pigeons produced the disease (Löffler). It seems doubtful whether the milder forms part with their virulence to birds, when cultivated artificially, or whether a special susceptibility is required in order to render the inoculation effective.

Prevention. Besides the general conditions of good hygiene, cleanliness, pure air, and pure water, the strict exclusion of the germ is the great desideratum. New fowls should not be taken into a flock, when they show any indication of disease in the mouth, throat, nose or eyes, nor when they come from a flock in which such signs of disease can be found. When examination of the flock, from which they are sold, cannot be made, the new fowls should be placed by themselves in quarantine until proved sound. Sound flocks should not be allowed to wander at large and mingle with the birds that are unsound, or open to suspicion. Neither should they be allowed to come in contact with manure from suspected poultry yards. If disease of air passages, mouth or eyes appears, separate at once the diseased fowl, and sprinkle roost, house and yard with dilute sulphuric acid, quicklime, or other disinfectant.

Treatment. Beside separation and disinfection the local use of antiseptics to the surface divested of the false membrane gives the best promise. Boric acid solution (4 ∶ 100) or sublimate solution (1 ∶ 5000) may be applied to the eye. For the nose and mouth somewhat stronger applications may be made.

Prevention of infection to man. The essential difference of the Klebs-Löffler bacillus of diphtheria in man, and the microbe of this affection in fowls does not exclude the necessity of avoiding contagion from birds to man. Among reported cases of such infection are: (1) That at Wesselhausen, where 4 attendants on the fowls contracted the disease from the sick fowls at a time when no other cases existed in the human population: (2) That of Sebdon where 6 persons suffered and 10 fowls fed by a hospital attendant also suffered: (3) That of Tunnis in which diphtheria prevailed in fowls, and soon also in those who fed them producing an extended epidemic: (4) That of Jacksonville, Ill., where a diphtheritic chicken, conveyed the disease, with fatal effect, to a child which fondled it (Moore).

These and other similar instances seem to show that the disease of the bird may become so virulent as to be communicated to man, and the disease of man so potent as to be transmissible to the bird. Every precaution therefore should be taken to prevent infection passing from one to the other.

FOLLICULAR CONJUNCTIVITIS.

Common in dogs. Violent congestion with enlargement of lymph follicles, or beneath the nictitans, dark red, like millet seed, also over sclera and lids. Enlarged lymph follicles with excess of lymphoid cells. Often chronic. Entropion. Infection. Treatment: astringent and antiseptic lotions: lunar caustic: cocaine and crushing of follicles: pure air: excision of nictitans.

Fröhner has drawn attention to the frequency of this affection in the dog, which according to him attacks 40 per cent. of the race. It is especially liable to begin on the inner surface of the membrana nictitans, and though it may be at first somewhat hidden by the severe congestion, yet when that subsides in part, the swollen follicles can be seen as dark red elevations, the size of a millet seed, when the nictitans has been everted. It may extend over the sclerotic and palpebræ. Microscopically these swellings are found to be enlarged lymph follicles, with an excess of lymphoid cells.

The disease tends to assume a chronic course and may cause entropion and other troublesome lesions. The diagnosis depends on the recognition of the swollen follicles, and especially in the depth of the conjunctival sac.

It is presumably infective yet all Fröhner’s inoculation gave negative results.

Treatment. In the earlier stages the common astringent and antiseptic lotions may be used. Sublimate, or boric acid lotions are especially valuable for their antiseptic properties. Should these fail, the eyelid and nictitans may be inverted and the individual follicles touched with a fine pencil of lunar caustic, the resulting smarting being lessened by application of cold water. In case they should still prove obstinate, the conjunctiva may be cocainized and the follicles individually crushed with ciliary forceps. Pure out door air is a prime essential in the treatment.

In extreme cases Fröhner counsels the excision of the membrana nictitans.

NEOPLASMS OF THE CONJUNCTIVA.

Pinguecula: fatty growth: Lipoma: Melanoma: Dermoid tumor in young dogs, calves, sheep. Cocainize the part and excise. Cold water: silver nitrate. Polypus. Pterygium.

A pale fatty looking elevation on the sclerotic at the inner side of the cornea is not unknown in the dog, resembling =pinquecula= of man. It has not been seen to prove harmful and may be safely ignored.

=Lipoma= has also been observed (Müller) and when troublesome may be removed by excision with scissors.

=Melanosis= is met with in gray horses in connection with the same disease of the skin of the lids, and usually with generalized pigment tumors. In the latter case surgical interference is useless unless it is to secure a very temporary relief.

=Dermoid Tumor of the Conjunctiva.= This consists in a cutaneous product, consisting externally of a mass of epidermic cells, beneath which are connective tissue, fat cells, and muscular fibres, glands and growing hairs. It usually extends inward from the outer portion of the sclerotic conjunctiva and may encroach on that of the cornea. It is firmly adherent to the sclera, and sometimes to the cornea by its base and deeper aspect, but the apex is free and more or less projecting. The color is yellow, or more or less blackened by pigment or even reddened by blood. It has been observed, above all, in dogs, Prince reports a case in a calf and Zundel in a sheep. The Cornell Veterinary College clinic has furnished cases in ox and dog. They have, however, nearly always been seen in young animals and are probably congenital.

These are easily removed from the eye anæsthetized by a 4 per cent. solution of chloride of cocaine. The inner projecting end of the tumor is seized by rat-tooth forceps, and carefully snipped off with sharp scissors curved on the flat. Where adherent to the cornea it must be carefully handled, but where attached to the thicker and more resistant sclerotic it can be dealt with more freely. A pencil of silver nitrate may be used to check the bleeding, or that may be effected by cold water freely applied.

=Polypus=, a small, pale, pediculated tumor of the conjunctiva is described by Lafosse and should be removed by scissors, and bleeding checked by cold, wet applications.

PTERYGIUM.

This name is employed to designate a triangular conjunctival fold broader at its sclerotic end and gradually narrowing to its corneal extremity, with loose, slightly overlapping borders, and firmly fixed to the structures beneath. It is more vascular than the surrounding conjunctiva, and its comparatively large blood-vessels have suggested the veins of an insect’s wing—hence its name. The growth may extend from either canthus toward or partly over, the cornea.

Möller and Leclainche claim its existence in dogs, though rarely to such an extent as to demand surgical interference. Dunewald operated on a case in the cow.

Unless growing, it need not be interfered with. It may be dissected up with scissors the narrow end being dragged on by forceps. Another method is to cauterize the narrow end with the electric cautery which leads to material contraction of the entire mass.

XEROSIS CORNEÆ (EPITHELIALIS). DRY KERATITIS.

This is described by Mayer as following distemper in dogs. It seems to begin in the epithelial layer of the conjunctiva, which becomes dry, lustreless, spotted, opaque and fatty so that water runs over it without wetting it. It may extend deeply into the substance of the cornea and lead to the development of a scar. When scraped and examined under the microscope the scrapings are found to consist of epithelium undergoing fatty degeneration and myriads of xerosis bacilli. As the disease takes occasion to attack by reason of the debility of the system, the treatment is mainly corroborative and tonic, including the arrest of the affection on which the weakness depends. The early application of antiseptics is desirable (iodoform 1, vaseline 10; mercuric chloride 1, vaseline 3000). Warm compresses and a bandage may be tried.

WOUNDS OF THE CORNEA.