50 DEPARTMENT OF AORICULTL'RE 



It is well cstablisheil tlint in the various trypanosomiases of animals, including 

 dourine, oedema in some form is the most constant feature. In dourined mares I 

 have found that the most frequent and constant sign of infection is the tumefied or 

 infiltrated mucous membrane of the vajjina. This condition has been observed in 

 70 per cent of my cases. In the absence of plaques, it is only in blood or mucus 

 from this lesion that I have succeeded in finding the dourdne parasites. In stallions, 

 the oedema usually commences in the mucous membrane of the urethra and meatus 

 \i'rinarius. This condition, however, is sometimes difiicult to ascertain or may escape 

 notice, the first sign of disease being noted in a tumefied penile sheath, intermittent 

 in eharacteri. 



Vesicles and ulcers. — As fas as T am aware, trypanosomata have never been 

 proven to he the actual cause oi vesicles and ulcers. These lesions do occur in a 

 small percentage of dourined marcs, and in a large percentage of dourined stallions 

 (see Table of Symptoms), but they are not, in my opinion, caused by the trypanoso- 

 mata. In the case of mare 36, I have recorded the finding of trypanosomata in fluid 

 from a vaginal vesicle. This was not a typical vesicle, and it would have been more 

 correct, I think, to describe the lesion as small, patchy or nodular infiltration of the 

 mucous membrane. From typical vesicles and ulcers I have neven succeeded in 

 isolating a trypanosome, and I am not aware that other investigators have succeeded 

 in doing so. I may state, however, the frequent occurrence of spirochsetae in these 

 lesions, in some micro-preparations these organisms appearing as in a pure culture, 

 •1 nests and colonies. This is of interest in view of the discovery of spirochaetse. 

 (now called the Treponema palUdvm) in lesions of human syphilis. Jewett, in his 

 publication, 'Notes on Blood — serum Therapy,' describes spirochfctse in cases of 

 canker and grease in equines. The appearance of the genitals in dourine when 

 ulceration and vesication are extensive, is not unlike the condition occurring in 

 * grease.' Professor Schaudin's interesting hypothesis on the transition of trypanoso- 

 mata into spirachsetse has provoked severe criticism, and is not generally accepted. 



Depigmentation. — In several cases of dourine I have observed depigmentation 

 independently of pre-existing vesicles op ulcers, and, further, that certain tissues, 

 especially the muco-cutaneous margins of the vulva, which had become depigmented 

 during a genital tumefaction, regained their colouring matter when these swellings 

 subsided. This phenomenon is unusual, I think, depigmentation generally persist- 

 ing for a lengthy period, if not i)ermanently and often associated' with vesicles and 

 ulcers. 



Conception and ahortion. — 'Infected mares do not, as a rule, conceive, but if 

 they do, almost invariably abort at about six months.' — (Pease.) 



'It has been noticed in India that from this time— (the primary symptoms) — 

 although the stallion is capable of efficiently covering the mare, he is entirely ster- 

 ile' — (Baldrcy.) 



Three mares in the 'third' stage of dourine have given birth to apparently 

 healthy offspring at this station. Three other mares, found to be affected with chronic 

 dourine, and in each of which the diagnosis has been confirmed by the finding of th^ 

 trypanosomata. had young foals at foot. At autopsies on slaughtered mares I have 

 several times found them to be pregnant. This is probably the exception. Neverthe- 

 less, abortion in my experience is a rare event, occurring only in those advanced cases 

 where there is emaciation and loss of co-ordination. In examining the semen of 

 dourined stallions I have found numbers of dead spermatozoa and rarely a motile 

 form. 



Methods of diagnosis.— It was hoped that in the absence of trypanosomata in the 

 blood and vaginal mucus, puncture of the enlarged lymphatics would yield good re- 

 sults, similar to the success of that method in the diagnosis of sleeping sickness. I 

 have punctured the glands in a number of cases and in various stages of the disease 

 but without ever finding a trypanosoma. Neither have I ever been able to find the 

 parasite in the cerebro-spinal fluid. 



