86 
AN ANNOTATED LIST OF THE ANIMAL 
PARASITES OF FOXES 1 . 
By WILLIAM A. BILEY. 
(Chief of the Division of Entomology and Economic Zoology , Department of 
Agriculture , University of Minnesota, Minneapolis.) 
Few people have any conception of the rapid growth and the importance of 
the new industry of raising black and silver foxes for their fur. According to 
Dearborn, 1917, the first profitable fox ranch was established in the Canadian 
Province of Prince Edward Island in 1894. This ranch, the forerunner of a 
remarkable industry, was stocked with two pairs of silver foxes, a rare and 
beautiful colour phase of the common red fox found in nearly all of the United 
States and Canada. 
Until 1910, the methods of growing of these foxes was kept a profound 
secret and practically “ monopolised ” by a few Prince Edward Islanders. Now 
there are many farms throughout Canada and the Northern United States and 
some foreign countries, notably Japan. Literally millions of dollars are invested, 
and prime breeding stock sells for many times the value of a high grade horse. 
In spite of the very heavy decline in prices of furs, prime pelts of the silver 
foxes are to-day worth from $500 to $1200 each. 
Until very recently practically no attention from an economic view-point 
has been paid to the animal parasites of foxes. They have been regarded as of 
merely general zoological interest, and that mainly from the systematic side. 
Now, with the rapid development of the fur farming industry, this condition 
is rapidly changing, for it is clear that intensive studies of any factors affecting 
the health or the quality of the fur of foxes are of great economic importance. 
Data regarding these points are not easy to obtain. This is in part due to 
the widespread ignorance regarding the nature of parasitic diseases. In part 
it is due to the fact that to-day the average grower of silver foxes depends for 
his largest profits on the sale of breeding stock and bence is loath to admit that 
he has any trouble from disease. Indeed, it is commonly stated that foxes are 
remarkably free from disease. However true this may be of the animals in 
nature, there is no reason* to hope that the condition will long prevail among 
the domesticated forms. 
In general it might be supposed that foxes would be subject to the same 
parasites as are dogs and other Canidae. How true this is we have not at 
present sufficient data to judge. Certain it is that many parasites which infest 
1 Published with the approval of the Director as Paper No. 225 of the Journal Series of the 
Minnesota Agricultural Experiment Station. 
