272 VETERINARY STUDIES 



tinued hot mild antiseptic treatment and gentle massage to 

 reduce the swelling and re-open the duct. 



Fistula. — This is a small opening in the side of the teat, which 

 opening connects with the milk duct and usually leaks milk at 

 least during milking. It is just an unclosed portion of an old 

 wound. 



Treatment. — When the cow is dry, sterilize the teat with tinc- 

 ture of iodine, then with a very slender pointed and sharp knife 

 that has been boiled and carefully handled to avoid infection, 

 rim out the old skin edge, so as to get a fresh raw edge for 

 healing; or sear very slightly and superficially in the fistula 

 with a hot wire. 



After this treatment, sterilize the wound and teat again with 

 the iodine, and bandage it with adhesive tape, covering plenty 

 of the teat. This must not be tight enough to interfere with 

 the circulation and should usually be left in place several days. 



Teat obstruction. — This may be due to a stricture or narrow- 

 ing of the canal as the result of an injury. Many cases are due 

 to small growths of various forms, which result from a mild 

 infection. They often form while the cow is dry and are found 

 at the next milking. Many of these cases can be cured by a 

 veterinarian's skillful surgical operation. 



Warts. — In case warts cause' trouble, they may be removed in 

 various ways, as by cutting them off with sharp shears, taking 

 a bit of normal skin all around the wart, or by tying them off 

 by a stout thread close to the teat. 



Hard milker. — Otherwise choice cows are often sold or killed, 

 because they are hard milkers. The difficulty in these cases is 

 usually superficial, the end of the milk duct opening being too 

 small. In many cases this can be cured by careful dilation with 

 a slender cone of smooth hard wood or metal. 



Sterilize the teat with tincture of iodine. Boil the dilator ten 

 minutes and handle in a way that avoids contamination. Insert 

 the dilator carefully, and leave in place between milkings. 

 Caution is necessary to avoid over-dilation and consequent leak- 

 age. The veterinarian uses special dilators or makes a small 

 cross-shaped incision in the outlet by a special instrument. 



Cowpox. — Cowpox is a contagious disease and apparently due 

 to a filterable virus which is very closely related to or identical 

 with human smallpox virus. Sheep-pox is probably an entirely 

 different affection. This trouble may be brought into a herd by 



