20 BULLETIN 1391, U. S. DEPARTMENT OF AGRICULTURE 
TOXIC DOSE FOR HORSES 
Only two horses were used. With these animals the poisonous 
effect on the average was produced by a feeding of 0.918 pound per 
100 pounds of animal, continued for 18 days. 
LETHAL DOSE 
The experiments give no definite indications of the lethal dose, 
compared with that necessary to produce intoxication. Some of the 
animals died with no further administration of the plant after 
symptoms appeared. Others received additional quantities of the 
plant. But the data do not make it clear that in the fatal cases 
there was any definite increase over the toxic dose. 
Generally speaking, the prognosis of cases in which markec 
symptoms of poisoning occurred was not good. Recoveries did occu 
under favorable circumstances, but one would rather expect a fata 
termination of the serious cases. 
COM PARI SOX OF TOXIC DOSES IN CATTLE, SHEEP, AND HORSES 
Inasmuch as in a general way cattle are made sick in 11 days b/i 
eating 1.5 pounds daily per 100 pounds of animal, and sheep ai 
made sick by eating 1.25 pounds daily for 3 weeks, it would appear 
that cattle are somewhat more susceptible to the poisonous effed 
of Aplopappus than are sheep. The horses were made sick on 
still smaller daily dose, about 1 pound per 100 pounds of anima' 
in 18 da} 7 s. Since the result on horses was from only two animals 
it can not be considered as being so exact as the results on the 
considerable number of sheep. So far as the experiments go, how- 
ever, it may be thought probable that horses are more easily affected 
than cattle. 
In this connection it may be noted that although the dosage of 
cattle was smaller than that of sheep, there were more recoveries 
of sheep. Of the sick animals, only 2 of the 9 cattle survived, while 
11 of the 14 sheep recovered. 
DURATION OF SICKNESS 
Many of the data in regard to the animals that recovered from 
the Aplopappus poisoning, were far from exact. Not only was 
it difficult to state definitely when animals had recovered, even if 
under constant observation, but in many cases the animals were 
t urned back to the owners before complete recovery had taken place. 
In most cases, in order to get a more pronounced effect, the plant 
was fed for a considerable period after symptoms appeared. With 
some few animals there are definite data in regard to the time during 
which symptoms continued after they were first observed. 
Although there is reason to think that sometimes recovery takes 
place only after a prolonged period, it seems clear that animals may 
come back to a condition nearly or quite normal in from one to two 
weeks after the feeding ceases. 
Table 4 gives the time between the first recorded symptom and 
death in the case of animals that died. 
