DISEASES OF DOMESTIC ANIMALS. 85 



character of fibro-cartilage to a certain extent ; third, internal and exter- 

 nal callus ; fourth, this sort of spongy bone becomes harder, lime salts 

 are developed, but the ends of the bone are still distinct from each 

 other ; fifth, the permanent and intermediate callus forms between the 

 broken ends. The provisional becomes absorbed to a certain extent. 

 This change goes on for some time, perhaps for years. These 

 reparative materials make the parts as strong, or stronger, than 

 before fracture. 



INJURIES TO THE VERTEBRA. 



Caries and Exostosis. — The atlas, the first cervical vertebra, is so 

 affected in poll-evil. If poll-evil has been present for years, the 

 matter cannot get away ; it burrows deeper, and irritation is set up 

 and the periosteum destroyed and caries set up ; and if caries is ex- 

 tensive, nothing can be done for it ; but if only slight, touching the 

 parts with dilute sulphuric acid may bring about a healthy action. 

 The parts may heal up and remain stiff ; in such a case there is more 

 or less exostosis. This may result from an injury to the parts, or 

 from poll-evil of an ordinary cause. The bone is liable to fracture 

 from casting the animal, or from striking the back part of the head, 

 etc. It is sometimes necessary to remove small spicula of bone, in 

 cases of anchylosis, or they may become detached, and act as an irri- 

 tant, giving rise to swelling of the tissues, and perhaps poll-evil ; the 

 symptoms are generally very plain. There is a discharge of offensive 

 matter ; you lay open the sinuses, and perhaps find a foreign body or 

 a part of a bone. If you remove this the irritation will cease and the 

 parts heal. 



The Axis is also liable to injury ; the odontoid process acts as a 

 pivot, upon which the atlas moves, and is more liable to be fractured 

 than the body of the bone. This is usually the result of violent injury. 

 A horse running fast, falling and striking the nose, or from slipping, 

 etc. Death is almost instantaneous, although there is a possibility of 

 an animal living for some time. I never noticed it in the horse, but 

 have known it in man. If the injury is anterior to the diaphragmatic 

 or phrenic nerve, instant death is usually the result. Other vertebrae 

 may become diseased ; there may be caries, necrosis and ossific 

 growths, and it is hard to say what may be the cause of these ossific 

 growths. Fractures of other cervical vertebrae may occur from being 

 halter-cast, getting the foot into the halter and struggling violently. 

 The transverse processes of the bones are occasionally fractured. 

 This, as a general thing, is not attended with any very serious results. 

 It may occur from the animal getting under the manger, or other such 

 injuries. 



Symptoms. — There is sometimes difficulty in detecting this, but if 

 an animal has been halter-cast, the neck swollen, there is a tendency 

 to carry the head to one side, and if you examine along the neck you 

 may be able to find the seat of injury, and you may be able to detect 

 crepitation. If you suspect a fracture, keep the animal as quiet as 

 possible ; bathe to allay the irritation of the soft tissues, and keep the 

 feed box pretty high, and keep the animal from moving the head 

 much, and you may keep him tied up and not allow him to lie down 

 for twenty-four or thirty-six hours. Bandaging is of little use. You 

 may meet with a case where the animal was not attended to, and re- 

 union did not take place, and there is necrosis of the parts ; they 

 become detached, and set up irritation ; there is a discharge — perhaps 

 heals up and then breaks out again, etc. There is some cause, some 



