520 Veterinary Medicine. 



The Senecio Jacobcea is doubtless largely prevalent in different 

 regions, and, wherever animals die with symptoms suggestive of 

 its toxic action, this weed should be carefully looked for as well 

 as the attendant conditions which might drive the stock to eat 

 it : — early spring before the grasses have come up ; — dry, or ad- 

 vanced seasons, or overstocking when pastures are bare ; — the 

 intimate mingling of the prevalent Senecio with the grass ; — the 

 abundant admixture of the flowering tops and upper branches 

 and leaves with the hay. 



Senecio Jacobcea. — Order Composites. Tribe Senecionidece . 

 (St. James's Weed, Golden Weed, Yellow tops, Ragweed, Rag- 

 wort, Canker weed, Staggerwort, Stinking Willie). Perennial, 

 erect, glabrous, glabrate or rarely cottony, stems i to 6 feet high 

 (occasionally more), furrowed, leafy. Lower leaves petioled 

 2-6 in. long : upper leaves sessile, clasping, pinnatifid or irregu- 

 larly 2 pinnatifid, divaricated, lobed or toothed. Heads yi in. 

 in diameter, numerous, forming a dense or rarely spreading 

 corymb ; involucre hemispherical .; bracts oblong, acuminate, 

 outer few, small, subulate. Rays spreading golden yellow. 

 Achenes of the ray angled glabrous ; achenes of the disc sub- 

 terete, hairy. 



Another species S. Canicida, indigenous to Pueblo, Mexico, is 

 very poisonous and is used for killing dogs. 



Symptoms in Cattle. The conditions of life give important in- 

 dications. The pastures or hay fed to the animals contain the 

 ragweed intimately mixed with the wholesome fodder. The 

 disease is known to occur more or less frequently in stock on 

 such pastures or hay. The victims, are as a rule, those that 

 have been on such land for at least One year, the first cases usu- 

 ally occurring about the end of the first year on the ground, and 

 the numbers encreasing, the longer they stay on the particular 

 aliment. Hence newly purchased cattle and young calves mostly 

 escape, while yearlings, two year olds and mature cattle raised 

 on the farm furnish the majority of the cases (Johnson). The 

 season of the year is to be noted : the cows are especially tempted 

 to eat the Senecio in early spring when the pastures are still 

 bare, in dry summers or autumns when the grass has been eaten 

 down and the less attractive ragwort is left, or when refreshing 

 rains have brought up a new growth of grass so intimately mixed 



