278 
THE VETERINARY SCIENCE 
affects the largest articulation in the hock joint. It is always 
best to try a blister before firing, for in some cases a blister 
will cure them all right. Blister with 
Biniodide of Mercury 2 drams. 
Vaseline or Lard 1 ounce. 
Mix thoroughly together. There is enough to blister an 
ordinary sized spavin twice. Apply half of it over the inside 
of the hock where, the enlargement is situated, rub in thor- 
oughly and grease the parts three days afterward. If an 
occult spavin, or if the enlargement goes right through the 
joint, use all the blister at once, that is, half on the inside 
and half on the outside. In three weeks wash the parts with 
warm water and soap, and blister again as before. Repeat 
the blister a few times, and, if not somewhat better, fire it 
with the feather iron. (See Fig. 45.) Use three of these irons, 
get them red hot, place a twitch on the horse's nose, have 
one of his front legs held up, and proceed to fire. Draw the 
lines as shown in Fig. 46, always a good half-inch apart each 
way. Run the iron lightly, 
as shown, until a white line 
appears, indicating that it is 
quite deep enough. The best 
place to heat the irons is at 
a blacksmith shop, and if the 
horse is very ugly it may be 
necessary to throw him in 
the same way as for castra- 
tion. Continue the firing and 
blistering until it effects a 
cure, which may take from 
six months to a year or two. 
Do not blister for six or 
seven days after firing. 
Work the animal a little be- 
tween times, as it is bene- 
ficial. Shoe him with a high 
heeled shoe, which helps to 
throw the strain off the hock joint. After firing and blister- 
ing, always keep the animal out of the water, as becoming 
wet scalds the hair and skin, causing it to become very sore. 
Fig. 46. — Method of "Firing" a Spavin. 
