24 BULLETIN 1391, U. S. DEPARTMENT OF AGRICULTURE 
SUMMARY 
A disease of cattle, commonly known as " alkali disease " or "mil 
sickness." has long been known in the Pecos Valley of Xew Mexicc 
and Texas. A disease of human beings commonly known as " mill 
sickness " also occurs in the Pecos Valley, and has generally beei 
identified with the disease of animals. 
The cause of this disease has been obscure. Some have thought 
it was produced by drinking alkali water: some have thought it 
due to a pathogenic organism; others have thought it caused by 
a poisonous plant, the rayless goldenrod (ApJopappus heterophyl- 
lus) being especially suspected. 
" Milk sickness " or " trembles " has been known in the Central 
and Eastern States for more than a century. It has been shown, 
however, that most if not all cases of milk sickness in the East 
are caused by the plant Eupatorium urticcefolium, commonly known 
as white snakeroot. 
The experimental work detailed in this bulletin has shown that 
cattle, horses, and sheep, ivhen given sufficient quantities of rayless 
goldenrod, develop all the typical symptoms of alkali disease or 
milk sickness. The toxic doses have been determined and the 
conditions under which poisoning is liable to take place have been 
discussed. 
It has been shown that the toxic substance may be excreted in 
milk, and that calves and lambs may be poisoned in this manner. 
It is probable that human cases of milk sickness arise from the con- 
sumption of milk or butter from cows feeding on the rayless 
goldenrod. 
It is shown that stock eat the rayless goldenrod only when con- 
fined in pastures where there is little good forage, so that the ob- 
vious remedy is to see that the animals are well fed. It is entirely 
practicable also to dig out the weed in fenced pastures. 
LITERATURE CITED 
(1) Curtis, R. S„ and F. A. Wolf. 
1917. Eupatorium ageratoides. the cause of trembles. In Jour. Agr. 
Research, vol. 9, pp. 397-404, illus. 
(2) Johnson, E. P., and W. A. Archer. 
1922. The principal stock-poisoning plants of New Mexico. N. Mex. 
Col. Agr. and Mech. Arts Ext. Circ. 71, 40 pp., illus. 
(3) Jordan, E. O.. and X. M. Harris. 
1909. Milk sickness. In Jour. Infect. Diseases, vol. 6, pp. 401-491, 
illus. 
(4) LUCKHARDT, A. B. 
1909. Additional notes on the bacteriology and pathology of milk 
sickness. In Jour. Infect. L>iseases, vol. 0, pp. 492-.">or>, illus. 
(5) Marsh, C. I>., and A. B. Clawson. 
1917. Eupatorium urticsefolium as a poisonous plant. In Jour. Agr. 
Research, vol. 11, pp. 099-710, illus. 
(6) and A. B. Clawson. 
1918. White snakeroot or richweed (Eupatorium urticrefolium) as a 
stock-poisoning plant. U. S. Dept. Agr., Bur. Anim. Indus. 
Doc. A. 1. 26, 7 pp., illus. 
( 7 ) Moseley, E. L. 
1909. The cause of trembles and milk sickness. In Med. Rec, vol. 
7."». pp. 839-844. 
(8) Thornber, J. J., and J. (1. Brown. 
L920. Botany, In Ariz. Agr. Exp. Sta. 31st Ann. Rpt., pp. 4">-4«3. 
(9) Wolf, E. A., II. S. Curtis, and B. E. Kaupp. 
1918. A monograph on trembles or milk sickness and white snake- 
root. N. C. Agr. Exp. Sta. Tech. Bui. 15, 74 pp., illus. 
WASHINGTON : GOVERNMENT TRINTING OFFICE : 1926 
