PARASITIC DISEASES OF CATTLE IN PUERTO ItICO / 
CONSTRUCTION OF PENS FOR YOUNG STOCK 
Dark, damp, and dirty pens or stables provide conditions favor- 
able for the development of parasites. Therefore, the proper con- 
struction of pens for confined animals is an important factor in the 
control of parasites and disease. The open-shed type of building in 
common use is well adapted for local conditions. Advantage should 
be taken of the fact that the sun shines nearly every day throughout 
the year in Puerto Eico. The sun's rays provide an efficient and 
inexpensive drier and disinfectant and are very destructive to the 
eggs and larvae of parasites. The pen should face east and west and 
the sides and roof should be so constructed that the direct rays 
of the sun can reach the entire floor space. Tight floors, preferably 
of concrete with drainage facilities, are essential. The mangers 
Figure 1. — A sanitary calf pen with movable roof. Exercising yard in foreground. 
and troughs should be protected from fecal contamination. A yard 
or corral may be used in connection with the pens, provided it is a 
bare lot, unshaded, and with good drainage. Young animals should 
have plenty of exercise and direct sunlight. 
A modified type of such a pen (fig. 1) has been constructed for 
trial at the station. The roof of this pen is built lower than an 
ordinary roof. It covers one-half the pen and it is set on rollers. 
Each day as the pen is cleaned the roof is moved over to cover the 
opposite half of the pen. Thus all parts of the pen are exposed to 
the sun on at least alternate days. Such a construction provides 
sufficient shelter for this climate and allows the sun to shine directly 
into the pen for a greater length of time than the ordinary type of 
roof. 
MEDICINAL TREATMENT 
The factors involved in the treatment of parasites, including the 
diagnosis, the specific drug to be used, the dose, and administration, 
usually require the knowledge, skill, and also the equipment of a 
