24 DEPARTMENT OF GAME AND FISHERIES No. 9 



but it takes about two years. Hook-worm infection is lessened, but round worms 

 are not affected. Concrete floors are of questionable value. 



Injurious Parasites 



Autopsy findings invariably reveal one or more parasites in ranch-bred 

 animals and also in those brought directly from the wilds. Some of these worms 

 have little significance in adversely affecting the health of the host. Others are 

 highly injurious and result in losses. 



Armed Lung Worm of Fox 



This dangerous worm (Crenosoma decoratum) was found for the first time 

 in Ontario in two red foxes forwarded to the farm directly from the trap lines. 

 They were in poor condition and did not eat well, and a purulent discharge 

 from the eyes and nostrils was observed. 



On autopsy, lung worms were found in the trachea (wind-pipe) and deeper 

 lung tissue. An area of inflammation with exudates of pus surrounded each 

 individual worm. It is easily recognized, being shorter and much heavier than 

 the common lung worm. The armed lung worm does not lay eggs, in the manner 

 of the common lung worm, but deposits living larvae in the intestines of the 

 fox. These pass to the ground, develop, and ultimately reinfect him. 



The symptoms may be confused with some of the infectious diseases, and 

 the fox should be isolated until a diagnosis is made. 



The use of wire floors raised some two feet off' the ground is advocated for 

 treatment. This will allow the larvae-infested droppings to pass to the ground 

 and at the same time prevent the fox from coming in contact with them. Single 

 boards placed around the inside wall of the pen will allow the fox considerable 

 scope for exercise and he will quickly learn to make use of them. 



Laboratory Diagnosis.- — The sugar or salt flotation test for the detection of 

 worm eggs is not satisfactory for larvae. The best results are obtained with the 

 Baermann isolation apparatus. If it is not available, the larvae can be recovered 

 by sedimentation. 



The feces are mixed with several times their volume in water and strained 

 through a fine screen to eliminate the coarser elements, the sediment being 

 allowed to settle. A small amount of the latter is taken up with a pipette and 

 examined under the low-power microscope. 



Kidney Worm 



This worm {Dioctopliyme renalis) has been found to be prevalent among 

 wild mink in the vicinity of the Experimental Fur Farm. It has also been found 

 in ranch-bred mink. Frequently a number of animals in the same ranch will be 

 affected. During the trapping season, trappers have been good enough to send 

 many carcasses to the farm. This has been of great help in studying parasitic 

 conditions among wild animals. 



The kidney worm must be considered as a very injurious one, and of much 

 economic importance to the fur trade. It is easily recognized, being one of 

 the largest of the round worms, ranging from 4 to 18 inches in length in the 

 mink. It is blood-red in colour. The favourite location is the centre of the 

 kidney, though we have found it, in mink, in the thoracic and abdominal cavity. 

 Given time the worm completely digests the kidney tissue, which becomes a 

 mere shell or capsule to house the worm. The worm is usually associated with 

 a bony deposit. 



