SILVER-FOX FARMING. 55 
Quality being equal, extra-dark (not more than 10 per cent silver) or 
dark (15 to 25 per cent silver) skins are the most popular on the 
market to-day and bring the highest prices. (Pis. I and IV.) 
SANITATION. 
The greatest obstacles that ranchers have to overcome in the fox 
industry are losses through disease — caused mainly by infestation, 
especially of the young, with parasites. Were it not for the fecund- 
ity of foxes their profitable production in the face of present heavy 
losses from diseases and parasites would be out of the question. 
Sanitation is most essential to success in fox raising. In the fol- 
lowing remarks no attempt is made to go into the details of diseases 
of foxes or their treatment, but attention is merely called to the sim- 
ple measures which may be used by any rancher to avoid to a large 
extent the losses of foxes in enzootics. Not only are cleanliness and 
rational methods of management relied upon by ranchers to keep 
their foxes in health and vigor, but they are the marks of a good 
rancher and a successful fox raiser. 
DISEASES. 
Distemper and other like diseases, characterized by pneumonia, 
are highly fatal and may be regarded as identical in character, so 
far as the practical management of the ranch is concerned. Specific 
diagnoses of these diseases can be made only by the most careful 
pathological examinations and by the assistance of a fully equipped 
laboratory. However, prophylactic measures found to be beneficial 
with any one of these diseases will prove efficacious with all. A 
rancher must remember that contagious and infectious diseases are 
caused by specific germs (bacteria and protozoans) and by parasite-, 
and that contagion and infection can not be spread from one ani- 
mal to another or from one ranch to another except through the 
agency of these organisms. 
Germ diseases and parasites may be carried in a multitude of 
ways — by the foxes themselves, on the clothing of persons, on ve- 
hicles, in feed, or by birds, dogs, and other animals. Following 
improper breeding and feeding methods does not necessarily cause 
disease, but careless methods may so weaken the constitution and 
vitality of an animal that it becomes more susceptible to disease than 
would otherwise be the case. 
Since infectious diseases can arise only through the presence of 
specific causative agents, it can readily be seen that prevention is 
very necessary. It should be constantly borne in mind that diseases 
caused by germs may be best prevented or controlled by thorough 
disinfection and scrupulous cleanliness. 
Many outbreaks of disease on fox ranches have been caused by 
infected feeds. Feed poisoning has been responsible for losses among 
old as well as young foxes. The preventive for this is to give clean, 
wholesome feed and to use clean methods in preparing as well as in 
feeding it. Some of the troubles which may be attributed to a nu- 
tritional defect of some sort are rickets, convulsions, sore eyes, abor- 
tion, abandoning young or killing young by vixen, premature cessa- 
tion or insufficiency of milk supply, failure to reproduce, and imper- 
