Coccidiosis in Cattle and Carabaos

In August, 1913, I was sent to look after the large number of work animals of the Calamba Sugar Estate at Canlubang, Laguna, where losses from obscure causes among cattle had been severe for some months past. It is difficult to study a disease or its etiologic factor, if one is unable to recognize it and distinguish it from other afflictions which may, and often do, co-exist. As far as I could remember, no method had been advanced of differentiating rinderpest beyond all question of doubt from other diseases. Most of the horses and ponies on this estate had perished from surra, but the microscope failed to show the well-known trypanosomes in cattle or carabaos, altho several hundred animals were subjected to the usual blood examinations. Many of the work-oxen were dying and a great number were in such a weak physical condition that they were unable to work. A reasonably careful survey of the situation showed at once that the deaths and condition of the animals were due to different factors. Many of the weak animals, however, suffered from irregular evacuations of the bowels; some had diarrhea, more or less severe, and others had what appeared to be "tropical dysentery." The latter were greatly emaciated and cachectic, but would eat as long as they could. Their temperatures were invariably a degree or two above normal. Others, in somewhat better condition, showed as a common symptom an irregular, persistent diarrhea, with only occasional distinctly dysenteric evacuations. Of about fifty animals that were kept together, some were always neat and trim, fat, and able to do good work, and never sick. Those that had been on the place several years appeared to do best. No particular type appeared to be immune, but the young animals were attacked in greater number than the old. Thirty work-oxen had died during the month of August. In previous months the losses had been, I was told, greater; various causes were ascribed, among others, poisoned weeds and gastritis due to excess of alkali in plants or water. As soon as possible the sick animals were segregated and divided into different groups so as to facilitate the study, and, if possible, permit an identification of the unknown disease. On August 30, the presence of rinderpest as one of the diseases was established. Clinical history, symptoms, and postmortem findings all sustained the diagnosis.