1931 ANNUAL REPORT, 1930 13 



Treatment 



Once the disease appears, strict sanitation and isolation are the two weapons 

 the rancher has to depend upon to fight the disease. Attendants should enter 

 the pen only when absolutely necessary. This rule should hold good, even at 

 the expense of pen cleaning. It is advisable to feed and water through the wire. 

 Foxes showing definite symptoms should be destroyed and the carcasses burned 

 or deeply buried. 



Medicinal treatment of the sick individual is of no avail. In the observation 

 of over two hundred cases not one fox recovered. 



The attendant handling sick foxes for treatment opens another avenue of 

 spreading the infection to healthy foxes. 



Isolation of all foxes that have been in contact with or located in pens near 

 the sick ones is imperative. These isolated foxes should be placed in the remotest 

 portion of the ranch and watched carefully for any developments. When pen 

 space is available, not more than two foxes should be kept together and better 

 still one fox to a pen. 



These foxes should have a separate attendant, but if this is not possible the 

 hands and footwear must be disinfected when going from one group to the other. 

 A shallow pan about half filled with bran and then poured full of disinfectant can 

 be left at convenient places for this purpose. If it is necessary to handle sick or 

 contact foxes a light coat which can be boiled is useful. 



BlOLOGICS 



The prevention of distemper by the use of biologies has been attempted 

 experimentally with encouraging results. Sufficient data, however, have not 

 been obtained to warrant specific statements as to their efficiency. Seven foxes 

 injected simultaneously with 10 c.c. Laidlaw-Dunkin anti-canine distemper 

 serum and 5 c.c. vaccine were exposed to infection and remained healthy. The 

 use of 10 c.c. doses of the serum alone appears to check the infection for some two 

 to three weeks and would, therefore, need to be repeated every three weeks or 

 less to insure protection until the infection subsides. It is to be hoped that 

 further research will settle the case of the usefulness of biologies in fox distemper. 



Comment 



While several authorities have stated that canine distemper may be trans- 

 mitted to foxes, there has been considerable controversy among men associated 

 with the fox industry on this subject. We have found that foxes when exposed 

 to natural infection by being placed in pens adjoining dogs suffering from clinical 

 distemper came down with the disease. It would appear that the early and 

 severe symptoms and the rapid fatal termination rather than the slower course 

 followed in dogs is due to the highly nervous constitution of the fox. The fox 

 being a wild animal has not been exposed to repeated infections as has the dog 

 and would therefore not have any natural immunity against distemper. The 

 infection appears to affect the central nervous system, and cases in foxes could 

 be likened to the so-called nervous form of distemper in dogs. In over 200 

 observed cases of fox distemper not one animal made a recovery. It would thus 

 appear that foxes have no natural resistance against the disease. 



Labor.\tory Procedures 



Bacteriological Examination. — Carcasses of foxes dead within 12 hours were 

 obtained and blood agar plates planted from the various organs. No patho- 



