PARASITES AND PARASITIC DISEASES OF HORSES 25 
centimeters of distilled water once a week. Ferrous sulphate may 
be given in a dose of 2 drams daily mixed with the grain feed. For 
best results, these drugs should be given over a period of 6 weeks to 2 
months. 
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 
floor, and supplying clean water. The disposal of stable manure is an 
important preventive measure, as is shown elsewhere in this circular. 
Little can be accomplished in the way of pasture sanitation except on 
farms where thoroughbred or other valuable horses are raised. On 
these farms the removal of manure deposits from. pastures may be 
practiced, as this procedure will remove almost all the parasite mate- 
rial before it can develop and spread. Such a procedure is necessarily 
troublesome and expensive and can be undertaken only by breeders to 
whom the question of expense 
is of secondary importance. 
The average breeder will have 
to resort to simpler and less 
radical measures, such as 
avoiding the overstocking of FIGURE 18.—Small strongyles of the horse 
pastures, frequent rotation of 
pastures, and special attention to foals. Where overstocking and the 
use of wet pastures are unavoidable, and rotation is impossible, 
reliance must be placed on treatment as often as necessary for control. 
Horse breeders, and even the general farmer, should pay consid- 
erable attention to the sanitation of paddocks in which the newly 
born foals are kept. The foals should be kept there for several 
weeks before they are put on pasture. Removal of manure from 
the paddocks, at least once a week, will cut down the supply of eggs 
and larvee to which the foals would otherwise be exposed. ‘This pre- 
caution will help to tide the foals over the most critical period of 
their lives. 
Young animals require special care much the same as children. 
Above everything else, a wholesome food supply and clean surround- 
ings are the best safeguards against disease. Special precautions to 
prevent foals from becoming parasitized are essential parts of sound 
management in horse-breeding establishments and on the average 
farm. 
THB SMALL STRONGYLES 
In addition to the blood strongyles or palisade worms, horses are 
commonly infested with numerous closely related species of stron- 
gyles, which are much smaller in most cases than blood strongyles, 
though some are almost as large. (Fig.18.) These worms occur 
in the colon and cecum and some of them produce visible injuries. 
One species, 7’riodontophorus tenuicollis, produces rather severe 
ulcers in the wall of the colon (Fig. 19), probably by means of the 
sharp teeth in their mouth cups. Some of the smaller horse stron- 
vyles, the many species known as cylicostomes, species of Trichonema 
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