PARASITES AND PARASITIC DISEASES OE SWINE 
13 
hogs should not be moved rapidly and must be kept under shade. The 
large fat hogs should be handled or moved only in the evening or early 
morning. 
Demodectie or follicular mange is caused by Demodex phylloides^ 
a microscopic, wormlike mite which lives in colonies or groups in 
the hair follicles and sebaceous glands. This mange is often found 
in market hogs, but infestations are mild and unimportant. This 
-kin disease is usually not recognized as mange and as being con- 
tagious. The lesions usually consist of small, hard nodules the size 
of a pin head, or larger, located on the skin of the head, neck, and 
shoulders. If the disease advances, which occurs only occasionally, 
these nodules break and discharge pus and suppurating cavities may 
form. Xo effective treatment is known, although frequent dippings 
in crude petroleum check the progress of the disease. In badly 
infested herds, animals with advanced cases should be destroyed, 
the remainder fattened for market and disposed of, and the premises 
cleaned and disinfected before hein<> re-tucked with healthy hogs. 
Sarcoptic mange is caused by Softcoptes sui*, a small whitish mite 
which burrows into the upper layers of the akin. The mites are 
usually easy to find among the Lesions on the inside edge near the 
base of the ear. They are barely visible to the naked eye if placed 
on a dark background. Sarcoptic mange is uncommon and it does 
not spread rapidly in this climate, but it is more noticeable and 
more serious than demodectie mange. It i- usually accompanied by 
demodectie mange. Stockmen usually recognize sarcoptic mange 
as a contagious parasitic skin disease. 
The same remedies and treatments are used for both lice and 
mange. Crude petroleum is the most effective known remedy, but 
in using it precautions must be taken to prevent burning of the 
-kin and Overheating of the animal. The arsenical solution as used 
for cattle licks is effective if hogs are dipped four times at intervals 
of 6 or 7 days. Detailed instructions for the treatment and control 
of hog lice and mange are given in a Farmers 1 Bulletin of the 
Tinted State- Department of Agriculture." 1 
The primary screw worm or gusano de la herida. Cochli&myia 
<imvricuH(K is the maggot of a blowfly which may attack any open 
wound of pigs and other animals. This fly is more abundant 
some rears and during certain seasons but no severe outbreaks have 
been known to occur. The treatment i- to apply a small amount 
of commercial benzol or chloroform to the infested wound. Benzol 
is preferable: and if it is Used, the blood and serum in the wound 
should first be swabbed out with cotton. After waiting 3 or 4 
minutes a small amount of the material should be introduced into 
the pockets of the wound and these should then be plugged with 
cotton. When the worms have been killed, the wound should be 
lightly covered with commercial pine-tar oil. All wounds should 
be treated with pine-tar oil to prevent attack by flies. 
The sand flea or nigua, Tu)uja penetrans, frequently attacks hogs, 
especially those that are raised near the seashore. The flea burrow T s 
into the skin between and above the claws and its presence pro- 
* IMES, M. HOG MOB AND HOG MANGE: METHODS OF CONTROL AND ERADICATION. U. S. 
Dept. Agr. Farmers' Bull. 10S5, lili pp., illus. 1933. I Revised.) 
