This disease, unlike that of the pig, has only been recognised within comparatively recent times, and only after Weisse’s experiments (St. Petersburg, 1841) on feeding with raw flesh was attention drawn to it, although as early as 1782 the Tænia saginata had been described by Goëze.
Measles in the ox is rarely seen in France, but is common in North and East Africa. Alix has found it in Tunis, Dupuys and Monod in Senegal, and it is common in the south of Algeria. The disease is due simply to oxen swallowing eggs or embryos of the unarmed tænia, a fact which explains the frequency of the disease in places where the inhabitants are of nomad habits, and consequently disregard the most elementary rules of public and general hygiene.
Fig. 39.—Anatomy of the Cysticercus cellulosæ (after Robin). A, Cyst; B, scolex with hooks; C, hooks; D, magnified fragment of cyst.
Fig. 40.—Section of a beef tongue heavily infested with beef measles, natural size (Stiles, Annual Report U.S.A. Bureau of Agriculture, 1901).
Furthermore, cattle in the Sahara, in Senegal and in the Indies, have a very marked habit of eating ordure, and as no attempts are made to prevent it, the risk to these animals is greatly increased.
As in the pig, the embryos which reach the stomach and intestine penetrate into the circulatory system, and are thereby distributed throughout the entire organism.
The development of the cysticercus is complete in forty days, and if swallowed by man in infected meat after this period it again gives rise to the Tænia saginata.
The age of the animals seems of less importance than in the case of the pig, for Ostertag and Morot have seen cases of beef measles in animals of ten years old.