1() BULLET] . PUERTO RICO EXPERIMENT STATION 
Importance. — The oodular worm is common and serious especially 
in the \\< t coastal area- and lower mountain regions. It occur- in 
cattle of the southern coastal plain, but it is considerably Less im- 
portant in this area. Similar to other roundworms, young calves 
arc more susceptible to an<l more seriously injured by infestation 
with nodular worms than older cattle. 
Symptoms "/>// lesions. — The injury by this parasite seems t«> 
occur Largely from the nodules. The Large Dumber of nodules result- 
ing from a heavy infestation prevents the intestine from functioning 
] roperly, and they are a constant source of irritation to the sensitive 
tissue of the intestinal tract. Because of the permanent natui 
the nodules, calves may recover slowly from a heavy infestation. 
The symptoms are dullness, lack of thrift, ami diarrhea. 
Treatment. — Preventive measures must he relied on for controlling 
this parasite. There is no known remedy that will reach the young 
worms in the nodules. As the injury by the parasite is Largely from 
the nodules, medicinal treatment cannot relieve or improve this con- 
dition. A drug to destroy the mature worms in the large intestine, 
which is both efficient and safe for cattle, has not been found. Such 
a drug would be valuable in eliminating the ova-producing worms 
and thus assisting in the control of pasture, field, and stable infes- 
tations. 
Pn vention.- — Pasturing young calves in the areas most favorable 
for this parasite should not be attempted. In the other areas calves 
should be maintained on dry hillsides. If dry pastures are not 
available, calves should be confined during the wet season. Confined 
calves can be protected from infestation by feeding the giant gi 
or other clean grasses and by providing clean, dry pens and corral-, 
i use this worm is very common and serious, and medicinal treat- 
ment is unsatisfactory, careful preventive measures are essential. 
HOOKWORM 
The hookworm {Bunostomum phlcbotoimun) is located in the 
small intestine. The female hookworm is about 2 centimeters 
(three-fourths of an inch) long, and the male is shorter and more 
-lender. 
Lift history. — The life history is similar to that of the stomach 
worm. Infestation is by way of the mouth and possibly the larvae 
are capable of penetrating the skin. 
Importance. — The hookworm is not as widely distributed as either 
the stomach or nodular worms. Considering the island as a whole, 
it is more common and serious among calves of the southern CO 
area. This parasite shows a preference for porous soils. At Maya- 
guez, where the soils are mostly a heavy clay, the worm is more 
common among the calves raised on the sandy soils near the 
shore. 
Symptoms and h sions. — The worm is a bloodsucker, and the symp- 
- and lesions are similar to those of the stomach worm. 
Treatment. — A solution containing the copper sulphate solution, 
as described for the stomach worm [p. 13), combined with nicotine, 
is effective for hookworms. To make this solution, add 1 ounce of 
LO-percent nicotine sulphate to 1 gallon of 1-percent copper sulphate 
(10 cubic centimeters to 1 liter). The dose for this combination is 
