Besides the natural difficulties of the road, the severity of climate, and the scarcity of fodder and fuel, the Transport Corps had to contend with every description of disease and misfortune--anthrax, rinderpest, foot and mouth disease, aconite and rhododendron poisoning, falling over precipices, exhaustion from overwork and underfeeding. The worst fatalities occurred on the Khamba Jong side in 1903. The experiments with the transport were singularly unsuccessful. Out of two hundred buffaloes employed at low elevations, only three survived, and the seven camels that were tried on the road between Siliguri and Gantok all died by way of protest. Later on in the year the yak corps raised in Nepal was practically exterminated. From four to five thousand were originally purchased, of which more than a thousand died from anthrax before they reached the frontier. All the drinking-water on the route was infected; the Nepalese did not believe the disease was contagious, and took no precautions. The disease spread almost universally among the cattle, and at the worst time twenty or thirty died a day. The beasts were massed on the Nepal frontier. Segregation camps were formed, and ultimately, after much patient care, the disease was stamped out.
Then began the historic march through Sikkim, which, as a protracted struggle against natural calamities, might be compared to the retreat of the Ten Thousand, or the flight of the Kalmuck Tartars. Superstitious natives might well think that a curse had fallen on us and our cattle. As soon as they were immune from anthrax, the reduced corps were attacked by rinderpest, which carried off seventy. When the herds left the Singli-la range and descended into the valley, the sudden change in climate overwhelmed hundreds. No real yak survived the heat of the Sikkim valleys. All that were now left were the zooms, or halfbreeds from the bull-yaks and the cow, and the cross from the bull and female yaks. In Sikkim, which is always a hotbed of contagious cattle diseases, the wretched survivors were infected with foot and mouth disease. The epidemic is not often fatal, but visiting an exhausted herd, fever-stricken, and weakened by every vicissitude of climate, it carried off scores. Then, to avoid spreading contagion, the yaks were driven through trackless, unfrequented country, up and down precipitous mountain-sides, and through dense forests. Again segregation camps were formed, and the dead cattle were burnt, twenty and thirty at a time. Every day there was a holocaust. Then followed the ascent into high altitudes, where a more insidious evil awaited the luckless corps. The few survivors were exterminated by pleuro-pneumonia. When, on January 23, the 3rd Yak Corps reached Chumbi, it numbered 437; two months afterwards all but 70 had died. On March 21, 80 exhausted beasts straggled into Chumbi; they were the remainder of the 1st and 2nd Yak Corps, which originally numbered 2,300 heads. The officers, who, bearded and weather-beaten, deserted by many of their followers, after months of wandering, reached our camp with the remnants of the corps, told a story of hardship and endurance that would provide a theme for an epic.