58 QUEENSLAND AGRICULTURAL JOURNAL. [1 Jay., 1898. 
Bacteriology. 
OFFAL-FED SWINE. 
Tux Year Book of the United States Department of Agriculture says that 
every slaughter-house is, from the very nature of things, a centre of disease, 
and, naturally, the poorer the condition of the premises the more dangerous 
they are. Ina majority af cases hogs are kept on the premises to eat the 
offal. Many of the premises are badly infested with rats, nearly 50 per cent. 
of which, on being examined, proved trichinous. Even if only a few animals 
are slaughtered each week, the total number may amount to several hundred 
during the year. At least one of the hogs has trichinosis; and when the offal 
of this trichinous hog is fed to the hogs which are raised on the ground, the 
latter cannot escape infection with trichinw. But that is not all. The 
slaughter-houses are, as said, overrun with rats; the rats feed on the offal, and, 
when feeding on the offal of a trichinous hog, they likewise cannot escape infec- 
tion with trichine. As a matter of fact, the rats captured at slaughter-houses, 
meat-shops, and rendering establishments were found to be affected in much 
greater proportion than rats taken from other sources. For instance, of sixty- 
three rats which were taken from slaughter-houses, 55°55 per cent. were 
trichinous, whilst none taken in barns or feed-stores or hotels were infected. 
Rats act as direct transmitters of trichinosis to hogs. If a hog kept at a 
slaughter-house eats a rat, the chances are fifty-five in 100 that it will 
become infected with the disease. Now, suppose that one of these establish- 
ments is burnt down or abandoned, the rats wander to the neighbouring farms 
and barns to obtain food ; and of every hundred rats which leave the slaughter- 
house grounds, fifty-five carry with them the disease known as trichinosis. 
This disease they transmit to farm hogs, if eaten by them, and that hogs do 
and will eat rats has been proved by experiment. Offal-fed hogs are liable to 
be infected to an extent varying from 10 to 100 per cent., and this custom of — 
feeding hogs at country slaughter-houses unquestionably is mainly responsible 
for the spread of trichinosis among the hogs of the two States visited. But 
trichinosis is not the only disease which the country slaughter-house spreads 
by offal feeding. It is well known that tuberculosis occursin cattle and hogs. 
Feeding the offal of tuberculous animals to hogs will transmit the disease to them, 
and these hogs when used as food may in turn transmit tuberculosis to human 
beings. Then the country slaughter-houses are also centres of infection for a 
number of animal parasites which are injurious to live stock and even to man, and 
which are spread by means of dogs. The latter, whilst eating the discarded organs, 
infect themselves with several kinds of parasites, of which the more important 
are: The Echinococcus hydatid, found in the liver, lungs, and other organs of 
cattle, sheep, hogs, and certain other animals. It varies in size from a small 
object as large as a hazel-nut to a bladder the size of a child’s head. This 
bladder contains numerous tape-worm heads; and when eaten by a dog, each 
head produces. a small tape worm. ‘The eggs of this tape worm are in turn 
transmitted to various domesticated animals and to man, and give rise to 
hydatids. In man it is said to be fatal in five years in about 50 per cent. of 
the cases. It can, however, be almost completely eradicated if slaughter- 
houses are properly cared for. 
The thin-necked bladder worm, which develops into the marginate tape 
worm when eaten by dogs, is scattered by them on farms, on roads, &c., and 
infects thus cattle, sheep, and hogs. The same thing occurs with the very rare 
gid bladder worm found in the brain of sheep. The tongue worm is found 
encysted in the viscera of domestic animals, and inhabits the nasal cavities of 
dogs, producing numerous eggs; which are transmissible to man. 
