DOURINE.
Synonyms. Definition: Contagious disease of breeding solipeds, with special lesions in generative and nervous system, and skin, and caused by a trypanosoma. Susceptible animals: horse, dog, rabbit, rat, mouse, ass. History: in Europe and America. Causes: contagion; coition; microbiology; trypanosoma equiperdum; its successive stages: 1. granules and refrangent spherules; 2; chromatin bodies with two prolongations; 3. fusiform body with nucleus and nucleolus and two flagella; 4. pyriform bodies with flagella; 5. fusiform body with nucleus, nucleolus and undulating membrane: in blood, sperm, milk, vaginal mucus, sores; disappears from blood in intermissions and rapidly after death. Lesions: phlegmons of generative organs, papules, vesicles, mottling, swollen inguinal glands, penis, testicles, caseation or atrophy, thickened lymphatics, nervous lesions, friable bones, arthritis, liver, spleen, kidneys, lungs, lack of red globules, anæmia, muscular atrophy; in mare, in dog. Symptoms: Horse: incubation 11 days, variable; preputial, scrotal, sub-abdominal swelling, catarrh of genital mucosa, vesicles, sores, swollen penis, semierections; paraphymosis, slight fever, tender loins, frequent micturition, paresis, swollen joints, tendons, emaciation marked anæmia, apathy, dementia, nasal ulcers, submaxillary swellings. Mare: vulvar swelling, distortion, leucorrhœa, eruption, spots of depigmentation, erection of clitoris, urine in driblets often, inguinal swellings, sterility or abortion, lameness, trembling, great anæmia and emaciation. Diagnosis: from urticaria: from glanders, generative lesions, no response to mallein, paresis: from chronic paraplegia, by its coition cause, and in horses only; from vesicular exanthema by gravity and nervous phenomena. Prognosis: Mortality 70 per cent. and upwards. Symptoms in ass slight: in dog severe and fatal; in rabbits severe. Treatment: prevent copulation, castration, local antiseptics early. Prevention: prevent copulation of infected and suspected animals, castrate, import only on certificate and on long quarantine.
Synonyms. Venereal Disease of Solipeds; Equine Syphilis; Maladie du Coit; Chancrous Epizoötic; Breeding Paralysis; Epizoötic Paraplegia.
Definition. A contagious affection of solipeds, transmitted by copulation, and attended by specific lesions in the generative organs and nervous system, such as local venereal swellings, chancrous ulcers and cicatrices, dementia and paralysis.
Susceptibility. As occurring casually the disease is essentially an equine one, yet the following species are susceptible to experimental inoculation in the order named: dogs, rabbits, rats, mice, asses. While the horse shows the greatest susceptibility, the ass is comparatively very resistant to the poison.
History. The malady has probably long prevailed in the east, yet it was first clearly distinguished in 1796 when described by Ammon as prevailing in the royal stud at Trakehnen in Northern Prussia. We have later descriptions of the disease in the same locality in 1801 (Hertwig), and 1807 (Ammon). It was found in Bromberg in 1817 to 1820 (Waltersdorf), also in Hanover (Haveman), in Austria and Bohemia in 1821–8 (Fischer), in Styria in 1821, in Switzerland in 1830, in France in 1830–2 (Lautour), in Silesia and Pomerania in 1833–40 (Fischer), in Italy in 1836, in Russia in 1843, (Fischer), in Silesia and Poland in 1830–40 (Freidberger and Fröhner), in Algiers in 1847–55, and in Syria and Asia generally and perennially (Daumas and Signol).
It appeared at Bloomington, Ill., in 1882, the first affected animal being a brown stallion that had been imported from France and which bore on his neck a brand like the letter D. In this locality it extended to a considerable number of breeding mares and stallions, and having been recognized by Dr. W. L. Williams, was largely stamped out by a rigid quarantine of diseased and exposed animals. Some exposed animals had, however, left the district, and isolated centres of infection have been since found in Nebraska and elsewhere in the United States.
It is not known to have invaded Belgium, Scandinavia, England, South America nor Australasia.
All indications point to Asia or North Africa as the primal home of the disease, as they still prove its perennial one.
Causes. The disease is transmitted by contagion and almost exclusively in the act of coition. Hayne has seen the affection in geldings, and Haxthausen in mares that had never been served. Schneider, Buffard, Nocard, Blaise and others have transmitted it freely by inoculation of blood and nervous matter, so that the possibility of infection through other channels than the generative organs must be admitted. But such irregular means of casual infection are so rare, and the probability of transmission of the virus from a non-breeding animal is so remote that in the practical measures of sanitary police, the breeding horses alone need be taken into account.
The extra vascularity of the male and female generative organs at the period of coition undoubtedly favors infection, as a latent or apparently recovered case will relapse under its frequent repetition. The abrasion of the epithelial surface also forms infection atria and favors new multiple points of infection.
The disease has occurred congenitally (Rodolff, Jessen). It has been claimed that the higher bred horses with lighter frames are the more susceptible (Fischer), but this is probably a delusion, the disease having been often introduced by the Barb and Arabian and propagated among their grade descendants. The heavy Percheron shows a very ready susceptibility and a virulent and fatal form of the affection.
Microbiology. That the affection was due to a microbe was clearly shown by its absence from every part of the world into which infected horses had not been brought. The secluded countries, Belgium, England, Scandinavia, that breed their own horses, the distant Australia, New Zealand and South America remained free in face of the constant presence of the infection in different parts of Central and Southern Europe, in Africa and Asia. The horses of America and South Africa showed a ready susceptibility to the virus brought by infected horses, and rigorous sanitary police control speedily cleared a district of the trouble.
Thanhoffer found in the blood, vaginal mucous, testicle, semen, spinal fluid, myelon, and roots of the dorsal and lumbar nerves cocci, especially streptococci and less constantly bacilli, to which he attributed the malady. More recently Schneider and Buffard have apparently demonstrated that an infusorian, the trypanosoma of dourine, is the essential pathogenic agent.
The Trypanosoma Equiperdum varies greatly in form at different stages of its growth or in different media. In the exudate of the slight early tumefaction, without as yet other symptoms, it is found as minute granules in groups, as larger spherical very refrangent bodies like very large cocci, each having a strongly staining nucleus, and as larger bodies in which a delicate membranous covering encloses one, two or three masses of chromatin and extends to form one or more points (club-shaped or fusiform). Each chromatin mass has a nucleolus on its outer surface or slightly apart from it. Twenty-four hours later there may be added: First, short, thick chromatin bodies, with two slightly undulating, pointed, membranous prolongations. Second, more delicate, fusiform bodies, each with one chromatin nucleus, a detached nucleolus, and the membrane prolonged into two actively moving flagella. Third, larger pyriform bodies with chromatin nuclei and nucleoli and the membrane prolonged into one or several flagella. Fourth, fusiform bodies, thick or delicate, each having a chromatin nucleus and nucleolus, and arranged singly or in groups of two, four, six or more, united together at one end and diverging at the other to form a stellate mass. These last, 20 to 30μ long by 1.5 to 2μ broad, may perhaps be the adult form of the parasite from which the small granular or spore forms found in the most recent lesions are derived. The fusiform outline, the deep staining central mass, with its adjacent nucleolus, and the pointed or flagellate membranous prolongations, more or less motile or undulating, are characteristic features.
In its morphology and evolutionary forms the trypanosoma of dourine has not been shown to differ from that of surra, nor the nagana or Tsétsé disease, the granule form, the spherical, the club-shaped or pyriform, the fusiform with more or less stellate grouping, are characteristic of all (Lydia Rabinowitsch, Kemper, Schneider, Buffard). The distinction is found in the pathogenesis of the two diseases.
With active cutaneous or mucous lesions, the parasite is usually found abundantly in the blood, sperm, milk, vaginal secretions, and the erosions of the vaginal mucosa or penis. During intermissions, however, and in the absence of local lesions, examination of the blood may fail to detect it, yet its inoculation on a dog will usually produce the affection. It disappears from the blood and tissues with great rapidity after death, so that, to prove successful, inoculations should be made before death or immediately after. They are ineffective after 48 hours.
Schneider and Buffard, Nocard and others found the trypanosoma in the blood and exudates of horses, asses and dogs, suffering from dourine, and failed to find it, in the same localities, in animals of the same species which were free from dourine. The infected blood, preserved for 24 hours in sealed glass tubes, and then inoculated on two dogs produced characteristic dourine, with the extensive production of trypanosoma in the blood, the destruction of blood globules, and the pathognomonic local lesions. Inoculation of two other dogs, with the same material, at the end of 48 hours produced a slight transient hyperthermia only, without local lesions or propagation of the parasite in the blood. The same blood inoculated after 15 days produced neither local lesion nor fever.
Lesions. Horse. In the early stages are found a phlegmonous or œdematous swelling of the sheath, scrotum, penis and inguinal glands and a yellowish liquid effusion into the scrotal cavity. The skin covering these parts may show a papular or vesicular eruption or if this has passed, a mottling with white spots shows where the lesions have been. Later still the inguinal glands are shrunken and have undergone fibroid degeneration and induration and the testicles, swollen or shrunken, contain centres of caseation. The connective tissue of the epididymus and cord is the seat of a gelatinoid exudation. The walls of the scrotum may be greatly thickened and the seat of abscess or of caseous degenerated hyperplasia. In advanced cases the testicles are usually abnormally small even if the scrotal mass is enormously distended. The sheath and penis may be the seat of more or less numerous ulcers, and swellings, contractions and distortions of the latter organ are not uncommon. The penis may, however, retain its normal dimensions. The walls of the lymphatics in the inguinal region may be the seat of hyperplasia, the thickening causing them to stand out like cords as in glanders. In the advanced stages the muscles, especially those of the hind limbs, become pale and atrophied.
The nerve centres undergo profound changes which have been studied by Thanhoffer. The pia mater in the affected parts of the spinal cord is the seat of active congestion and thickening. The central canal of the cord is dilated (syringomyelia) more at one point than another, contains more than the normal amount of liquid, and the neuroglia around it is thickened and fibrous (sclerosed). The substance of the cord, both white and gray, shows congestion, blood staining, at points foci of softening, and at others induration (hyperplasia of the neuroglia). The nerve cells are modified in various ways, some being granular, some discolored by fine granular pigment, some having enlarged and multiplied nuclei, and some show vacuoles. The nerve filaments often show a granular degeneration extending from the nerve cell into the axis cylinder, and the latter is liable to be varicose or uneven in size. In the affected portion of the cord leucocytes are numerous and hyperplasia is often present. The neuroglia especially tends to encrease, and apart from the foci of softening tends to give a special firmness to the substance. At intervals, in the perivascular spaces, may often be found minute (microscopic or macroscopic) blood clots. The subarachnoid and subdural fluid is encreased and may be pinkish. At the roots of spinal nerves, especially in the dorsal and lumbar regions, a gelatinoid exudate may invest the nerve, distending the connective tissue beneath the neurilemma and even occupying the interval between the nerve filaments. Sometimes large corpuscular bodies are found between the nerve fibres.
The cerebral meninges, especially the pia mater, are congested and opaque. Foci of softening are by no means uncommon and the cerebral ventricles contain an abnormal quantity of fluid.
The bony tissue generally has lost its consistency and the medullary matter may be unduly reddened. The large joints contain an excess of synovia somewhat pinkish in color, and the ligaments of the hip joints are often congested, thickened and softened. The articular cartilage may even show patches of blood staining.
The intestines are usually nearly empty, soft, pale and flaccid, and Ruthe has in one case observed rounded ulcers on the mucosa. Fibroid thickening on the peritoneal surface may indicate a previous exudate.
The mesentery is thickened, with infiltration and has a yellowish discoloration and the mesenteric glands are usually enlarged, softened and friable, though sometimes firm and contracted. The lymph glands adjoining the generative organs are often swollen, pigmented and studded with foci of caseation, varying in size from a pea upward.
The liver is softened and congested or fatty. The spleen is small.
The kidneys are usually large, but flaccid, pale and bleached.
The thoracic organs may show little change, though hypostatic inflammation and foci of caseation or suppuration may be present.
The blood is pale and watery and forms a loose, pale, diffluent clot, while there is an extraordinary diminution of red globules and a relatively great encrease of leucocytes.
In advanced stages the muscles are pale, anæmic and shrunken especially those of the hind limbs.
Mare. In the mare in addition to the lesions of the internal organs and blood, the following may be noted in connection with the generative system. Phlegmonous or œdematous swellings, sores or ulcers on the lips of the vulva, and on the vulvar and vaginal mucosæ. The parts become variously distorted, and the vulva, habitually open may expose the swollen and ulcerated clitoris. A crop of papules or vesicles, running into sores or ulcers may appear on the urethral orifice, the vulva and adjacent skin, and even though overlooked, their seats are marked later by loss of cutaneous pigment and the formation of small white spots. The mammæ are sometimes inflamed, œdematous and tender, with suppurative or necrotic foci and the adjacent lymph glands are enlarged by infiltration or contracted by sclerosis.
Dog. These resemble those in horses. In the bitch genito-urinary congestion, inflammation and catarrh, subcutaneous infiltration under the belly and inside the thighs, swelling of the inguinal lymph glands, emaciation, and pallor and atrophy of the voluntary muscles are marked features.
Symptoms. Horse. Incubation may last from one to eight weeks (Maresch), but is usually 11 days from the infecting service. It may be abridged by a special susceptibility, and by repeated infections and hence the more acute cases are especially seen in the male in daily service. In some such subjects local genital infiltrations are speedily followed by paralysis or vertigo which cuts off the patient in a few days.
More commonly the malady is chronic though varying in different countries, epizoötics or even in particular cases.
The first symptom is slight swelling of the anterior border and raphe of the sheath, which gradually extends backward to the scrotum and inguinal region and forward on the abdomen it may be as far as the brisket. This may be hot and painful, but is usually œdematous, cool and painless. The infiltration affects the end of the penis, the meatus may be red and angry with a slight muco-purulent discharge, and red spots vesicles and ulcers may stand out clearly on the pigmented surface. Williams never saw such eruptions in the American cases and doubts their existence except as the result of injuries. There are frequent semierections and service is still possible. Later the engorgement extends to the specially pendent testicles, inguinal glands and others adjacent. Paraphymosis is occasionally seen or, more commonly, the penis hangs out of the sheath soft and flaccid and erection seems impossible. The local swelling may become excessive, pressing the testicles up against the inguinal ring, or suppuration and extensive abscess may follow. Appetite is retained and the temperature remains moderate (100° to 102° F.).
The local swellings may almost completely subside, except a slight tumefaction of the end of the penis, hence some (Fischer) have held that the cutaneous lesions are the primary ones, yet the start of infection at the generative organs and the fact that a stallion often infects a number of mares before there is any suspicion of his own infirmity is evidence enough of the genital seat of the earliest lesions.
The cutaneous lesions, which are essentially secondary, but highly characteristic, appear from forty to sixty days after the infection (Schneider and Buffard). They are from a quarter of a dollar and upward in size (in some old horses much smaller), and rise abruptly from the healthy skin, becoming the more marked that the hairs upon them stand erect. These may arise suddenly and subside again in one day, or give out a serous exudate which mats the hairs into a tuft. They may, however, last four or five days. These are more patent after a full drink of water, or after sprinkling or sponging with water. Even when they have been overlooked these results may often be seen later on colored skins, in the presence of many circular white spots entirely devoid of pigment. The most common seat of these cutaneous lesions is the hind parts (anus, tail, croup, quarters), but they may appear on the sides, neck, shoulder or thighs.
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.
5th. If any stallion or mare is imported from a country in which dourine exists it should be accompanied by an official certificate showing that it has not in the past three years been exposed to the possibility of infection with dourine.
6th. In the absence of such certificate the imported animal (capable of breeding) should be kept in strict quarantine for the period of three years.
7th. A much more radical measure, which may be made to supersede all of the above, would be to castrate every soliped (stallion or mare) which has suffered from the disease in the past three years, and every such animal that has by coition been exposed during that length of time to even a remote opportunity for contagion. This would embrace all apparently sound mares that had been served by a stallion which had shown slight symptoms of the disease, or by a stallion which had not himself shown such symptoms, but which had served a mare that had shown such symptoms; or one that had served a mare that had not shown such symptoms, but that had been previously served by a stallion which had shown such symptoms, or that previously covered a mare that had shown such symptoms. In such cases the State might well afford to indemnify the owner for any reduction in value of the castrated stallion from that borne by the animal as a prospective breeder, the breeding for which indemnity is sought being understood to count only from a date of three years after the sanitary castration. A mare once attacked should be remorselessly castrated or killed. A perfect recovery in a horse can be better attested; that of a mare is always uncertain, and most secondary outbreaks after the apparent extinction of the poison have come from breeding mares that have apparently recovered, or that after exposure have shown no appreciable symptoms.
When a State is so lost to all sanitary considerations as to abandon an affection of this kind to take its course, the owners of stallions and mares cannot be too careful to avoid the exposure of their valuable breeders to the risk of infection. Each mare brought for service should be admitted only when accompanied by a certificate showing all previous services in the last three years, with the identification of the stallion, and this irrespective of whether the service has been fruitful or not. In such certificate the owner of the mare should bind himself to make good all damage or loss that may accrue from his failure to set forth in the certificate every such service and every symptom of illness affecting the generative organs from which the mare has suffered in the three years antecedent.
The owner of the stallion should give a similar guarantee that the horse has in the past three years served no mare that was in any way open to suspicion, and that the animal has not suffered from any affection of the generative organs which had any of the characteristics of dourine.
No mare should be served which shows swelling, nodules, distortion, or gaping vulva, a muco-purulent discharge, or too frequent or too prolonged heats.
No stallion in such locality should be allowed to serve which shows pasty swelling of the sheath, swelling, shrinking or distortion of the penis, red, angry, tender meatus urinarius, or a muco-purulent discharge.
Unless in case of Arabian horses the appearance of white spots on the dark ground of the sheath, penis, vulva, or perineum, should be ground for debarring from service until an absolutely stainless record covering a number of years has been shown.