PARASITIC DISEASES OF CATTLE IN PUBBTO HTCO 13 
sick animal should be placed in a clean dry pen. Either dry hay or 
clean fresh grass obtained from a hillside or dry held should lie fed. 
The animal may be muzzled after eating and drinking. The pens 
should be scrubbed, sprayed with a hot disinfectant, and dried. 
The organism is very resistant to ordinary disinfectants, but it can 
be destroyed by heat and drying. 
Pn v ration. — Cattle should be kept away from low. wet pastures. 
An open manure pile draining into a pasture or grass field is danger- 
ods. The ingestion of dirty- water from pools and marshes must be 
avoided. For confined calves, clean fresh grass, clean water, and 
clean dry pens should be provided. 
WORxM PARASITES 
THE STOMACH WORM 
The stomach worm (Haemonehus contortus) (fig. 3, A) is a round- 
worm found in the fourth stomach (abomasum) of cattle. The 
worms are 12 to 30 millimeters (y 2 to 1*4 inches) long and about 
as thick as an ordinary pin. The female worms are larger than the 
males and have a spiral striping. The smaller male may be dis- 
tinguished by the fact that the posterior or tail end of the body is 
flattened and expanded. 
Life history. — The eggs are passed in the feces and develop on the 
ground. In 10 days or sooner the infective larvae crawl up on 
the blades of grass when there is a rain or dew. Animals become 
infested by grazing, by eating contaminated forage grasses, or by 
picking up the larvae which have developed in damp and dirty 
pens. 
Importance. — The stomach worm is one of the most common and 
most serious parasites of cattle in Puerto Rico. Calves of less than 
(3 months of age are more susceptible to and more seriously injured 
by infestation than older animals. Healthy calves of 1 year of age, 
or older, which are fed properly, become quite resistant to inf< 
tion. Mature cattle often harbor a few stomach worms but are 
rarely injured by them. 
Symptoms and lesions. — The worm attaches itself to the lining of 
the stomach and sucks blood, producing pin-point punctures with 
hemorrhages. The first symptoms are dullness and unthriftiness, 
and, later, anemia and edema. The condition knoAvn as " papera " in 
which there is a swelling underneath the jaw (fig. 4) is a sign of 
infestation by this parasite. This swelling is also found in infesta- 
tions with the hookworm and liver fluke. 
Treatment. — A satisfactory treatment is by drenching with a 1-per- 
cent solution of copper sulphate. The dose for a calf 3 months of 
age is 60 cubic centimeters (2 ounces), and for each additional month 
of age add 15 cubic centimeters, or at the rate of approximately V/ 2 
ounces per 100 pounds (1 cubic centimeter per kilogram) of live 
weight. All food should be withheld 18 hours before, and both 
food and water 4 to 6 hours after, treatment. 
To make a 1-percent solution of copper sulphate dissolve 100 grams 
of copper sulphate in 1 liter of boiling water and add 9 liters of 
cold water, or at the rate of one-fourth pound of copper sulphate to 
3 gallons of water. Select only the clear blue crystals of copper 
