414 



TR YPA NO SO MID M 



C. Invertebrate host a Glossina : — 



Rats refractory. Large forms, 24 microns — Cazalhom. 



D . Invertebrate host unknown : — • 



I. Attacks horses: — 

 [a] In Venezuela — V eneziielense. 



(h) TnMorocco, separated by cross immunity —Marocanum. 

 (c) In Algeria, separated by cross immunity— Berber um. 

 II. Attacks horses and cattle :— 



In Annam- — Annamense. 

 III. Attacks cattle:— 



In Italian Somaliland — Cellii. 



Trypanosoma equinum Vosges, 190 r. 

 Synonym. — -T. elmassiani Lignieres, 



T. equinum, discovered by Elmassian, is the cause of mal de caderas in 

 horses and dogs in South America. 



Morphology. — This parasite closely resembles T. brucei and T. evansi. In 

 length it is 22 to 24 [x, and in breadth i'5 ix, and it has the same measurements 

 in different species of animals. It is very active, but its principal characteristic 

 is that the kinetonucleus is very insignificant. 



Life-History. — Multiplication is by equal binary division. It agglomerates, 

 and has been cultivated by Thomas and Breinl on a rabbit's blood and chicken- 

 broth agar medium. 



It can be inoculated into the ordinary laboratory animals. Its mode of 

 propagation is not well known, but Migone has shown that it is the cause of a 

 disease which kills the capybara {Hydrochcerus capybara) , which appears to be 

 the reservoir for the parasite, as monkeys inoculated from a sick HydrochcBVUs 

 died in seventeen days. How the disease spreads from the Carpinchos {Hydro- 

 cJicBYUs) to the horses is not clear. Dogs may be infected by eating diseased 

 animals, and then from the dog the infection may be spread to the horse by 

 fleas, because they have been found to infect rats. Some authorities consider 

 that it may be spread by members of the Tabanidae (Chrysops ?) and by 

 Stomoxys, but Neiva has infected THatoma infestans Klug, and its faeces 

 produced the disease in guinea-pigs when placed on the conjunctiva. 



Pathogenicity. — Mal de caderas is a very fatal disease among the horses of 

 South America, The first sign of the disease is weakness, which makes rapid 

 progress, though the appetite remains good. The temperature is febrile, and 

 after a variable period the hind-quarters become paralyzed and the horse drags 

 its limbs, the hoofs scraping the ground. As it walks it staggers, the hind- 

 quarters oscillating from right to left, which characteristic gives the disease 

 its name of mal de caderas, the disease of the hind-quarters. In the stable 

 it can support itself against the walls, but in the open air it staggers and falls. 

 There may be albuminuria and haematuria, and an eruption on the neck, 

 shoulders, and hind-quarters. The eyelids show conjunctivitis and chemosis. 

 The horse lives about two months after the paralysis sets in. 



Congestion and enlargement of the spleen and mesenteric glands are seen 

 in post-mortems. The kidneys are affected, nephritis and interstitial haemor- 

 rhages being noted. There are also serous exudations into the peritoneum, 

 the pleura, the pericardium, and the spinal canal. 



Trypanosoma soudanense Laveran, 1907. 

 Type of Trypanosoma evansi causing tahaga in dromedaries in the Upper 

 Niger, el debab in Southern Algeria, and the zousfana in horses in Southern 

 Algeria. Carriers: Tabanidae. Yoriie and Blacklock consider this to be the 

 same as Castellanella evansi. 



Trypanosoma togolense Mesnil and Brimont, 1909. 



Type of Castellanella evansi, parasitic in horses and cattle, and the cause of 

 nagana in Togoland . 



