PARASITIC DISEASES OF CATTLE IN PTJEBTO UICO 19 
Technically, the amount to use is 12 pounds of copper sulphate per 
second-foot of flow for running water and about 6 pounds per acre- 
foot of water for marshy land. As this amount of copper sulphate 
is too small to distribute evenly, it should be mixed with a carrier. 
If the copper sulphate is distributed uniformly, there is little danger 
of animals being poisoned by it. 
The best season of the year for the treatment is a short time after 
the heavy rains of the rainy season. As the land gradually dries off, 
the remaining water tends to collect in depressions or pools and the 
snails follow the water line and become concentrated in these centers. 
Later, if treatment is not undertaken, the snails disappear in cracks 
and holes in the soil and cannot be reached by ordinary methods. 
Until island-wide eradication measures are undertaken, it will be 
necessary to repeat the operation every year or as often as the snails 
reappear. If live snails are found after an application, the treat- 
ment should be repeated. Usually one treatment at the right time 
of the year is sufficient for that year. At the experiment station at 
Mayaguez the pastures and malojillo vegas are treated some time 
during November or December. 
TAPEWORM 
The tapeworm (Monieza expansa) (fig. 3, G) is a whitish, seg- 
mented worm which may attain a length of several feet. It is found 
in the small intestine. 
Life history. — Unknown. 
Importance. — This worm is very common in some districts. Of 
the cattle slaughtered at Mayaguez, this tapeworm seems to be more 
common in those obtained from the district of San Sebastian. The 
heaviest infestations occur more frequently among pastured animals. 
Confined calves that are kept in sanitary pens and fed on the clean 
grasses occasionally become infested. 
Symptoms and lesions. — The worm causes obstruction of the intes- 
tine and irritation, and infested animals become unthrifty, weak, and 
emaciated. Diarrhea is a common symptom. Occasionally the pres- 
ence of the worm is detected by the passage of several or many of the 
end segments in the feces. 
Treatment. — Various treatments have been recommended. How- 
ever, most of the recommended drugs are unsafe for the young stock 
which harbor the heaviest infestations and are in greatest need of 
treatment. Care must be used also in giving any anthelmintic, as 
many of the young animals besides harboring various kinds of para- 
sites are improperly nourished and thus are poor subjects for treat- 
ment with any potent drug. 
Kamala administered in capsules in doses of 1 to 2 drams (4 to 8 
grams) for calves up to 1 year of age may be used. It should not 
be given to very young animals or to those in a weakened condition. 
Periodic treatment with the copper sulphate-nicotine sulphate com- 
bination as recommended for the hookworm seems to reduce infesta- 
tions with this tapeworm. 
Prevention. — Xo dependable preventive measures against these 
tapeworms can be recommended, owing to the fact that the life 
history is unknown. However, as the ova are the starting point of 
