24 CIRCULAR 148, U. S. DEPARTMENT OF AGRICULTURE 
on weight, regain their working capacity, and make an all-round 
improvement. 
Treatment.—lIt is advisable to fast the animal 36 hours before 
treating for large strongyles. Oil of chenopodium is effective for 
their removal. This drug should be given in a dose of from 4 to 
5 fluid drams (16 to 20 cubic centimeters) for a 1,000-pound animal, 
or at a dose rate of 1 fluid dram (4 cubic centimeters) for each 250 
_ pounds of weight, immediately preceded or followed by 1 quart of 
raw linseed oil or by an aloes ball. Cases of excessive purgation 
have been reported in some instances following the use of raw linseed 
oil. It is possible that this undesirable action is due to impurities in 
the product; conse- 
quently a good grade 
of oil should be used. 
A mixture, said ta be 
without the undesir- 
able effects of raw 
linseed oil, has been 
recommended as fol- 
lows: For wean- 
lings, castor oil, 4 to 
6 ounces, and neu- 
tral oil, 1 pint; for 
yearlings and 2-year- 
olds, castor oil, 6 to 
8 ounces, and neutral 
orl, 1 pint ;: for. 3- 
year-olds and older, 
castor oil, 8 to 10 
ounces, and neutral 
} oil, 1144 pints. 
FIGURE 17._—Horse suffering from gross infestation with . Carbon tetrachlo- 
parasites (strongylidosis). Note marked emaciation. ride is also of value 
Following treatment for the removal of parasites, this 
TSE Hn een ea for the removal of 
large strongyles. It 
should be used in treating pregnant mares as oil of chenopodium is 
dangerous for such animals. It may be given in doses of 6 to 12 
‘fluid drams (25 to 50 cubic centimeters) for a 1,000- pound animal. 
Normal butylidene chloride is another drug which 1s effective for 
the removal of large strongyles. It should be given in a dose of 3 
fluid ounces (90 cubic centimeters) for a 1,000- pound animal, and 
followed in five hours by raw linseed oil at the rate of 1 quart per 
1,000 pounds of weight. It is probable that the dose of normal 
butylidene chloride could be reduced to 2.5 ounces (75 cubic centi- 
meters) for a 1,000-pound animal, without materially reducing the 
efficacy of the drug. One treatment with any drug will not always 
remove all worms present and, if necessary, treatment may be re- 
peated in from four to six weeks. 
Prevention.—Preventive measures designed to control strongyles 
consist (1) in rotation of pastures, so far as possible, avoiding low 
and wet pastures, and (2) sanitation of stables to prevent larve from 
developing to the infective stage and from contaminating the feed 
and water. This is accomplished by daily removal of manure from 
stables, supplying the feed in boxes and racks well raised above the 
