CURATIVE TREATMENT OF SURRA IN EQUINES                101

for Yorke [1921] would seem inclined to regard it as probable that the general
circulation in subjects apparently cured of trypanosomiasis may later be re-invaded
by strains originating not only from the cerebrospinal system but also from the
tissue spaces and circulation back washes. However, in the absence of definite
experimental evidence in support of Yorke's statement, it does not seem necessary
to depart from the conventional practice of regarding the spinal canal as the only
seat of origin of relapse strains.

The main problem that requires elucidation at the present moment relates,
therefore, not to the genesis of relapse strains but to whether " Bayer 205 " does not
possess the requisite degree of " penetrability ", so as to be capable of finding its
way into the spinal canal even when the drug is introduced intravenously alone into
the general circulation. Edwards [1928] has already obtained results pointing to
the conclusion that " Bayer 205 " is endowed with such properties (ante), whilst the
experience of later workers has also shown that in the treatment of clinical cases
of equine surra, a single intravenous injection of " Bayer 205 ", at the rate of
5 to 8 grms. per 1,000 lb. body-weight, is usually capable of effecting a cure
under field conditions in India and in a great majority of such " cured " cases, no
relapse has been found to occur during a post-treatment observation period extend-
ing over a year or more. If these findings are confirmed by future experience,
then the problem of controlling surra will have been solved in a manner consistent
with, the requirements of field workers in India, for in that event the treatment
will involve neither the technicalities of the intrathecal puncture nor the multipli-
city of injections entailed by the combined method.

                                          REFERENCES.

Abdulla Khan (1932). A Brief Note on Surra, Its Diagnosis and Treatment. Punj. Vet. Journ.,
February, pp. 1-8.

Baermann (1922). Die Behandlung der Surra mit "Bayer 205 ". Beihefte z. Arch. f. Schiffs-u.
Trop.-Hyg.,26, 73-123. [Abstr. in Trop. Vet. Bull., 11, 2-3; 1923.]

-----------(1923). Die Behandlung der Surra mit " Bayer 205." II Mitteilung. Arch. f. Schiffs-v
Trop.-Hyg., 27, 210-217. [Abstr. in Trop. Vet., Bull., 12, 5-6 ; 1924.]

Bakker (1925). Notes on Surra in Padang Sidempoean. Ned.-Ind. Bladen v. Diergeneesk. en.
Dierendeelt, 37, 153-177. [Abstr. in Trop. Vet. Bull., 13, 76-78; 1925.]

Bubberman (1931). Bekämpfung von Trypanosomiasen in Nederländish-Indien. 11th Internat.
Vet. Cong. London, 3, 600-613.

Bubberman, Douwes & Van Bergen (1925). The Use of " Bayer 205 " in Equine Surra in the
Dutch East Indies Veeartsenijkundige. Mededeeling, No. 50. Dept. v. Landbouw,
Nijverheid en Handel, Buitenzorg. 64 pp. [Abstr. in Trop. Vet. Bull., 13, 73-76 ; 1925.]

Edwards (1928). The Chemotherapy of Surra (Trypanosoma evansi infections) of Horses and
Cattle in India. Mem. Dept. Agric. India, Vet. Ser., 4, 1-100.
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