1932 ANNUAL REPORT. 1931 19 



evidently in a run down condition and quite thin. The mink had previously 

 been in normal health, becoming dull and showing a distinct disinclination for 

 food. A weakness in the hind quarters may develop and convulsions may 

 set in a few hours before death. Others may die in a comatic condition. The 

 mink is usually found lying stretched out on its side in the nest box. In most 

 fatalities the body assumes a curled-up position. 



Autopsy. — The thoracic cavity is invariably filled with a blood-tinged 

 serous fluid. The lungs are swollen and red; when incised, a frothy, blood- 

 stained exudate oozes out. Trachea and bronchi are often partially filled 

 \vith the same exudate. Other organs are usually normal. 



Prevention. — The construction of many mink houses afforded no protection 

 from the direct rays of the sun, other than the nest box. In hot weather the 

 nest box becomes over-heated and humid, the mink succumbing to heat 

 prostration. Should the mink remain in the unprotected run, sun stroke with 

 accompanying congestion of the lungs occurs. If possible, natural shade should 

 be provided for the house, but if it is not available, artificial shade should be 

 erected. It is essential that fresh, clean drinking water be provided at all 

 times. The young should be weaned from the female at seven to eight weeks 

 and not allowed to run in the same pen with her. 



Lymphatic Leukemia in the Raccoon 



An autopsy made on a male raccoon at the time of pelting revealed the 

 presence of a greatly enlarged spleen. The surface appeared roughened, due 

 to irregularly defined elevations, the summits of which appeared white. On 

 cutting into the organ it seemed to be somewhat harder than normal. The 

 cut surface was a pale brownish-red colour, permeated with white, the hard 

 areas measuring from about one-eighth inch to a quarter of an inch in diameter. 

 Sections examined microscopically revealed practically no normal spleenic 

 tissue. This was replaced by areas having no definite structure surrounded by 

 trabecula. The weight of this organ was 33.3 grams as compared with 41 

 grams, which is the normal weight of the spleen from an animal of the same 

 weight. The liver was pale red in colour, slightly enlarged, somewhat firmer 

 than normal and contained a number of well defined white areas. The intestines 

 and kidneys appeared anemic. 



The animal which appeared to be in failing health, was small in size and 

 had a stunted unthrifty appearance. It belonged to a litter of four raccoon 

 born last spring. The other three were thrifty and well developed for their 

 age. They, along with their mother, were caught in the wilds and sent to 

 the Ontario Experimental Fur Farm last September where they were kept 

 together in a pen until pelted. 



Mink Post-Mortem Diagnoses 



No. of Animals Dia^aosis 



20 Pneumonia 



22 Congestion of the lungs 



19 Parasitism 



23 Food poisoning 



2 Ulcerated stomach 



2 Nephritis 



14 Distemper 



2 Rachitis 



2 Metritis 



1 Peritonitis 



5 Oedema of the sheath 



3 Dental conditions 



