1931 ANNUAL REPORT, 1930 25 



The worm can sometimes be detected in the living mink; the enlarged 

 capsule can be felt as an enormously enlarged kidney. Pen-raised mink infested 

 with the worm may show a tendency to drag the hindquarters, and may become 

 paralyzed. Fits, emaciation, and loss of appetite are also noticeable. The egg 

 laid by the worm is ovoid in shape and dark-brown in colour and has a well- 

 defined capsule. It can be recovered in the urine and occasionally in the feces 

 through contamination. 



Treatment for the elimination of the worm is not possible, owing to the 

 location in the kidney. Prevention is, however, practicable and easily accom- 

 plished. 



Prevention. — From evidence gathered this year, mink ranchers are advised 

 to cook fish taken from sluggish waters for at least ten minutes in boiling water. 

 The catfish appears to be a large factor in spreading the disease. The immature 

 or larval form of the worm lives in freshwater fish at some stage of its existence 

 and develops to maturity when swallowed by the mink. Of the many fish 

 inhabiting sluggish streams we can only discriminate against the catfish species 

 at the present time, though further studies may reveal that others carry the 

 larv^al form of the kidney worm. 



Tapeworms 



The tapeworms {Di phyllohrothrium latum and Diphyllohrothriiim cordatum) 

 have not been considered a serious problem in foxes and have seldom been found 

 in foxes sent to the Fur Farm for post-mortem. This year, however, they were 

 found in forty-five examinations. Two species have been identified, D. latum 

 and D. cordatum. The life cycle of D. latum has been fully worked out, and 

 D. cordatum is in every likelihood similar. 



In the fox they were from 2 to 14 inches in length according to the stage of 

 development reached, and were found inhabiting the lower portion of the 

 intestines. With minor differences, they are typical tapeworms, being flat and 

 distinctly segmented. 



It has been definitely established that the infection is acquired through eating 

 fish, the final larval stage having been found in pike, lake herring, perch, and 

 many others. If fish are eaten in the raw state, the young worms locate in 

 the intestinal tract of the fox and reach maturity in from five to six weeks. It is 

 altogether likely that in certain areas the fish are much more heavily infested 

 than in others. If post-mortems are done on pelting foxes and they are found 

 to be infested with these tapeworms it would be advisable to cook the fish in 

 boiling water for ten minutes. 



Treatment. — Arecoline hydrobromide given by the mouth was found to 

 remove tapeworms in foxes. However, it should be kept clearly in mind that 

 this is a dangerous drug, if not used with proper precautions. It should not be 

 given to foxes suffering with heavy lung-worm infestation as it has a tendency 

 to affect respiration. Normal foxes can tolerate a dose of 1/4 grain, but not more 

 than 1/8 grain is recommended if lung worm is at all prevalent. 



After treatment, the fox should be placed in a clean crate and the feces 

 examined for the expelled tapeworm. This is best accomplished by stirring the 

 feces in several times their volume of water. The tapeworms will be noticed 

 in the disintegrated fecal matter. 



Physaloptera Sp. 



Worms belonging to this genus are frequently found in raccoon, and from 

 external appearances are very similar to the ordinary round worm. They 



