134 CAUSES, SYMPTOMS AND TREATMENT OF 



the cleft. It f»ive8 rise to irritation, spreads, impairs the secretion, 

 and gives rise to this discharge. 



Causes. — There are extrinsic and intrinsic causes. It is sometimes 

 seen in the fore feet in navicular disease. Any irritation of the foot 

 may produce it. The extrinsic cause is wet and filth, allowing dung 

 to accumulate, irritating the parts, etc. Heavy horses are more dis- 

 posed to thrush, canker, cracked heels, etc. Thrush is not so preva- 

 lent in a cold climate. 



Symptoms are plain. The horse does not actually go lame, but goes 

 tender, and if he steps upon something hard, he will flinch ; and there 

 is a discharge of a peculiar odour, etc. 



Treatment. — It is easily treated. If due to ordinary exciting 

 causes, as filth, etc., remove the cause. In some cases take off the 

 shoes and pare down the parts — remove any detached parts — and 

 immerse the foot in a bucket full of water. Use astringent dressings 

 — the carbolic lotion, one part of acid to eight, ten or twelve of water, 

 or chloride of zinc five or ten grains to an ounce of water — and apply 

 well into the cleft, and then apply some tow or cotton saturated with 

 tar. There are other remedies, one is dusting the parts with powdered 

 calomel ; pressure is useful after these. Where horses get frog pres- 

 sure thrush is not so common. Thrush may terminate in canker, but 

 it is the exception and not the rule. Use sulphate of copper, butter of 

 antimony solution, and the tincture of chloride of iron. A change of 

 dressings is of benefit in most chronic cases. 



PUNCTURES AND PRICKS. 



Punctures from a nail passing through the sole, etc., may or may 

 not be serious, according to depth and direction. If a puncture is in 

 the frog, near the navicular bursas, it is liable to be severe, for it may 

 injure the tendon, or even the os pedis. When so, the whole limb may 

 swell and become gangrenous. If it passes in the frog, and its course 

 is to come out above the frog, it is not very severe. Sometimes it only 

 just penetrates the sensitive structures, and the animal is not lame, 

 but a little tender, in which case you have difficulty in diagnosing — 

 and some of the greatest mistakes that are made by a veterinary 

 surgeon are in diagnosing lameness. You may imagine there is lame- 

 ness and heat in the hock, and perhaps there is heat there from the 

 irritation in the foot. 



Symptoms. — If it is in the hind foot, the animal knuckles ; if in the 

 fore foot, it is pointed, and when weight is thrown upon the affected 

 foot the other is quickly brought forward. Examine carefully ; take 

 up the foot and tap it with a hammer, and he will generally evince 

 pain ; and he may show pain when you tap upon the side opposite the 

 injury, and not show it when you tap upon the injured side. The 

 horse will perhaps knuckle just when starting, for a few steps, and 

 then walk all right. If in the frog, and you cut off some of the soft 

 part, there may appear a small dark speck, tap up on this and it 

 causes pain, then it likely is a puncture. 



Treatment.— It was at one time recommended, although not much 

 laine, to cut the sole down and immerse the foot in poultices ; but 

 there is generally no necessity for cutting much, but put the animal off 

 work for a few days and apply a poultice. But sometimes the irrita- 

 tion increases instead of subsiding. Then it is necessary to cut down 

 thoroughly, and let the matter escape ; if you do not it will extend 



