Part 80

Tenderness of the loins may now be shown, with frequent, painful micturition, but the penis becomes more and more paretic, so that coition becomes encreasingly difficult or impossible. Paresis also shows in the hind limbs, the animal remains recumbent a great part of the time, rises with difficulty, starts suddenly forward at the fetlock, and drags the toe on the ground in walking. Swelling of the joints and tendinous sheaths, with attendant lameness, is not uncommon. The appetite remains good, yet emaciation and weakness make marked progress.

The advanced stages are characterised by marked anæmia, paraplegia and dementia. The visible mucosæ are pale, emaciation advanced, the patient stubs his toes and sways in walking, and finally drops unable to rise; or he stands with hind legs straddled and semi-bent, and largely oblivious of all around him. He may be too stupid to eat unless the food is placed in his mouth, and yet the neigh of another horse or a mare may draw forth a feeble retort, as if the deranged generic instincts remained. Swelling, or even abscess of the lymph glands, axillary, submaxillary or inguinal, is usually present, and muco-purulent discharge with ulceration of the nose or eyes is not uncommon. The joints crack when moved and fractures are common.

The duration of the disease is two or three months, the progress being more rapid in winter.

Mare. Vulvar swelling eight or nine days after service, with ejection of urine in jets, contraction of the vulva, redness, swelling and erection of the clitoris, and a muco-purulent discharge are marked symptoms. European observers note nodules, vesicles and ulcers on the mucosa and adjacent skin, but these were not observed in the American cases (Williams). Yet later they showed the characteristic white spots. Switching of the tail, stamping of the hind feet and painful straining to urinate are followed in certain cases by ejection of the urine forcibly in jets or in small dribblets. The catarrhal discharge is at first watery, but later becomes viscid, sticky and white, yellow or grayish, or even red. It mats together the hair of the tail and thighs, and putrefies, exhaling a repulsive odor. The swelling involves the space between the thighs and often implicates the mammary glands and even the floor of the abdomen. The inguinal glands are often involved, and hyperplasias with degenerations and even abscesses may appear in this region. As in the stallions the local lesions may have periods of advance and subsidence, and in favorable cases, that are not again served, there may seem to be a temporary recovery. The mare, however, remains infecting, and if served the local disease is at once roused into activity. The button-like skin eruptions appears on the quarter as already noticed of the horse and in grave cases may caseate or suppurate and burst, forming an indolent and intractable sore. The dark skin of the vulva and perineum becomes marked by white spots or by irregular patches caused by the confluence of several such spots, which for ordinary breeds of horses are highly characteristic of this disease. Many Arabian horses naturally acquire such white spots on the dark skin, and in pure Arabs and grades this appearance need not be held as evidence of dourine.

Infected mares rarely conceive, and any that do so are likely to abort before the sixth month.

The systemic symptoms, nervous, paralytic, tremulous, dyspeptic, atrophic, cerebral and cachectic follow a similar course as in the stallion.

In grave and progressive cases the lesions of the generative organs become very marked. The lips of the vulva become rigid and distorted so that it remains constantly open and the erect clitoris continually exposed. The skin of the vulva is tense, dry and shining. Lameness is shown in one or both hind limbs, knuckling over at the fetlock, shortening of the step, planting the toe first and the heel later with a jerk, lack of balance, paresis and even inability to rise.

A disposition to trembling is common to both sexes, as is also an intolerable itching of the skin which may make the animals tear the lower parts of the limbs with the teeth. In either there may be a local paralysis of a lip, an ear, an eyelid, or some other part of the body. In both sexes the disease tends to extreme anæmia, debility and emaciation, and to infective internal inflammations (lungs, bronchia) or septic or purulent infections.

Diagnosis. From urticaria this disease is to be distinguished by the absence of lesions of the generative organs in the former, by its association with change of food and digestive disorder and by the absence of all evidence of contagion.

From glanders it is to be distinguished in the same way by its casual transmission by sexual connection only, by its restriction to breeding animals, and by the irresponsiveness of the victim to the mallein test. The progressive paresis and hebetude are valuable diagnostic phenomena.

From chronic paraplegia it is distinguished by the same prevalence in breeding solipeds only, and by its mode of transmission.

The greatest difficulty is experienced with the slight and comparatively occult cases, and in some of these the history of the infection of a number of breeding animals, which have been served by the same horse may be the one guiding point for a number of the cases. For sanitary purposes it is well to treat as suspicious animals all mares that have been served by a stallion which is in the line of infection. This suspicion would attach also to any stallion that had served a mare which had been to a diseased or suspected stallion, and to all mares that have been served by the suspected stallion after he had been to the suspected mare.

From simple vesicular exanthema dourine is to be distinguished by its comparatively slow progress, and by the uniformity of the lesions of the generative organs and nervous system, which are lacking in the vesicular affection.

Prognosis. A certain number of animals recover from the milder attacks which have not become complicated by the grave trophic and nervous lesions, but as in glanders, recovery from severe attacks and in the advanced stages is practically unknown. The mortality is set at 70 per cent. and upward.

Symptoms in the Ass and Mule. The disease usually remains discrete, the lesions in the generative organs or other seat of infection being the marked symptoms, and recovery the rule. Œdema of the end of the penis, obliteration of the folds around the orifice of the urethra and eversion of the urethral mucosa are the most constant features, distinct even in semi-erection. Œdema of the sheath and skin eruption may follow. Exceptionally a mule proves as susceptible as the horse, and shows the disease with the same fatal severity.

Symptoms in Dog. A bitch, 15 days after vaginal injection of the infected equine blood, showed severe vaginitis and hyperthermia (100°). On the 23d day she aborted, followed by muco-purulent discharge, vulvar œdema, pallor of the mucosæ, anæmia, rapid emaciation, paresis and occasional convulsions. Blood drawn from the vulva contained the trypanosoma. She died on the 66th day. The temperature rose to 103°.

Two male dogs that lined the above infected bitch showed after 12 days, engorgement of the sheath and scrotum, muco-purulent discharge, and abundance of the trypanosoma in the blood of the affected parts. Cutaneous lesions on the loins, thighs, sides or forehead, showed erection of the hair, with infiltration, or shrivelling and bloodlessness.

Other dogs showed arthritis, corneal opacities and ulcers, hypopion, cataract, nasal discharges, facial periostitis, dyspnœa and syncope.

Symptoms in Rabbits. Rouget found in inoculated rabbits, extensive gangrene of the skin, involving even the cranial bones, ulcerative keratitis, hypopion, panophthalmia, following on the earlier genital troubles of vaginitis, swelling and discharge.

Treatment. Some cases recover spontaneously a few may be aborted in the earliest stage of the disease, but cases that have advanced to any extent and assumed a grave character are practically hopeless.

An important element in treatment is to do away as far as possible with the cause of generative excitement since the disease is aggravated and more rapidly advanced by frequent copulation. Rodloff from a very wide experience speaks highly of castration of the stallion. Castration of the mare has not been specially advocated and the absence of marked lesions in the ovaries, may deter the veterinarian, yet whatever promises to lessen in any degree the genesic excitement is not to be despised, and the measure has besides a sanitary value for other animals.

Early local treatment is the most promising, and especially if it can be applied to exposed animals during apparent incubation. Injection of the urethra, sheath, vulva, vagina and uterus with antiseptic lotions, and apply them to the external sores. Mercuric chloride 1:2000, carbolic acid 2:100, silver nitrate 1:250, calcium chloride 1:100, or chlorine water may be taken as examples. When local swellings have supervened it would be entirely appropriate to incise them freely or even to excise them and cauterize thoroughly with stronger agents.

Internal treatment by mercuric chloride 1½ to 3 grains, potassium iodide 2 to 5 drs., arsenic 7 to 14 grains, has been widely used but to little purpose. The same may be said of Rodloff’s treatment by tonics and carminatives (sal ammoniac, camphor, iron, angelica, gentian, ginger and valerian.)

Prevention. The one thing to be secured is the prevention of copulation with any animal that has been affected, or exposed to this disease in the past three years.

1st. Any stallion or mare once affected must be excluded from breeding for at least three years after apparent recovery.

2d. Every such animal that has been exposed by copulation with a suspected animal must be excluded from breeding for the same period even if no active symptoms have been shown.

3d. Every affected or exposed animal, should be quarantined in the hands of his or her owner and placed on an official register and the sale, gift or loan of such an animal, or its movement to a new place where it might propagate the disease should be made a misdemeanor.

4th. In any county or district in which the disease exists all stallions and mares should be registered and none should be allowed to be used for breeding purposes without an official certificate showing that each of the animals mated is free from all suspicion of having been exposed to this infection.