10 DEPARTMENT OF GAME AND FISHERIES No. 9 



construction of the mink house are sometimes advisable to provide better 

 protection from the weather. 



Iodine Poisoning in Mink 



Recently our attention has been drawn to a toxic condition occurring in 

 mink caused by the excessive use of iodine. The use of this drug has been widely 

 advocated among fox and mink breeders as a preventive against certain diet 

 deficiency conditions. 



These conditions are claimed to be caused by a lack of iodine in the system, 

 due to the improper functioning of the thymus gland. This gland supplies the 

 necessary iodine required for normal nutritional metabolism, and if lacking, 

 nervousness, and an enlargement of the glands, particularly the thyroid, result. 

 It is also advocated that a sufficient quantity of iodine is necessary to counteract 

 poisons which may form in the body during the digestion of food. 



There appears to be little evidence either practical or experimental that 

 fur-bearing animals are subject to iodine deficiency, and if it be used in the daily 

 rations it should be administered with care and precision. 



The following correspondence is typical of a number of cases dealt with 

 during the past year. "I am operating a fur farm and last spring I was advised 

 to feed my mink at least one drop each daily of tincture of iodine and was told 

 that I could feed one drop three times a day with safety. This advice was 

 given by a person who should have a fair knowledge of the amount and effect 

 of iodine when used as a drug for mink. 



I fed each mink one drop daily all last spring and summer and several of 

 my largest feeders, which would probably get more than one drop became 

 nearly naked, in fact one lost all of his fur and was as hairless as when born. 

 One yearling lost his teeth and several of them died near fall. Would this 

 condition be caused by the iodine I have been giving my mink?" 



If iodine in practically any form is given to any animal in fairly large doses 

 and for a considerable period of time, toxic effects may be manifested or a 

 condition termed "iodism" may result. This is evidenced by a dry scurfy 

 condition of the skin, the fur becomes harsh, dry and stairy in appearance. 

 The eyes are reddened and watery, the appetite becomes dull and the affected 

 animal will abstain from taking water. 



On post-mortem the tissue appears to be somewhat dried out. A slight 

 inflammation and catarrhal condition of the nasal passages and pharynx are in 

 evidence. The lining of the stomach and intestines show inflammation, also a 

 slight gelatinous substance may be found adhering to the mucosa, which indicates 

 a catarrhal condition. The stomach appears contracted and contains no food. 

 The intestines also appear somewhat shrunken and may contain soft watery 

 faeces. 



If mink owners are of the opinion that their mink require iodine in order 

 to maintain the proper functioning of the body, "potassium iodide" is perhaps 

 the best form of iodine to use. It may be prepared for mink as follows: Take 

 one ounce of potassium iodide and dissolve in one quart of water. Take one 

 ounce of this solution and make up to one quart with water. One ounce of this 

 weak solution is probably sufficient for the daily iodine requirements of thirty 

 to forty mink. This can be mixed with the ration in any way which suits a 

 particular method of feeding, but if possible, attempts should be made to mix 

 it thoroughly with the food. 



Food Poisoning in Mink 

 Food poisoning appears to be the most common source of mortality among 

 mink at the present time. A few years ago, it was also very common among 



