EFFECTS OF FEEDING ANIMALS WITH TRICHINOUS MEAT 
CONTAINING NONVIABLE TRICHINAE 1 
By Benjamin Schwartz, 
Zoological Division , Bureau of Animal Industry, United States Department of 
Agriculture 
INTRODUCTION 
In the extensive literature on trichinosis there appears to be no 
records of experiments dealing primarily with the effects produced 
by the ingestion of meat containing nonviable trichinae. Various 
workers have assumed, without adequate experimental evidence, 
that meat containing nonviable trichinae is innocuous in so far 
as the production of any of the symptoms that characterize trichinosis 
is concerned. Flury in 1913, 2 found that apart from the mechanical 
injuries caused by living trichinae in the host animal, the products 
formed as a result of their metabolic activities coincident with their 
growth and development in the host, as well as the products formed 
as a result of the degeneration of the muscles which they invade, 
are highly toxic to animals when injected parenterally. Flury, in 
fact, has explained the entire symptom complex of trichinosis, such 
as the gastric and intestinal disturbances, vomiting, local irritation, 
muscle stiffness, capillary hemorrhages, edema, blood changes, fever, 
and respiratory difficulties, as the result of (1) the toxic substances 
produced by the parasites, and (2) the degeneration products of the 
muscles which they invade. His careful studies, involving numerous 
experiments with various extracts of trichinous muscles, as well as 
the evidence furnished by various investigators regarding the toxicity 
of nematodes in general, naturally suggest the possibility that dead 
trichinae may also be injurious because of the liberation of possible 
toxic products as a result of their digestion, and that the ingestion 
of trichinous meat containing nonviable trichinae may give rise to 
at least some of the symptoms of trichinosis or to other unpleasant 
symptoms. 
In order to determine the effects produced on animals by meat 
containing nonviable trichinae, several experiments were performed 
in which such meat was used. On account of their marked sus¬ 
ceptibility to trichinosis, rats were chosen for the tests. Rats are 
likely to show severe symptoms not only after the parasites become 
established in the muscles but also during the intestinal stage, and 
usually die at this early stage of the disease even when they are fed 
very small quantities of heavily infested trichinous meat. Since 
rats frequently die of trichinosis before the larvae have begun to mi¬ 
grate, it may be assumed that death is due, in all probability, to a 
severe intoxication, coincident with the rapid growth and develop¬ 
ment of the parasites in the intestine, other probable contributory 
1 Received for publication June 19, 1925; issued January, 1926. 
* Flury, F. beitrage zur chemie und toxikologje der trichinen. Arch. Expt. Path. u. Phar- 
makol. 73: 164-213, illus. 1913. 
Journal of Agricultural Research, 
Washington, D. C. 
( 945 ) 
Vol. XXXI, No. 10 
Nov. 15,1925 
Key No. A-105 
