364 DADD'S VETERINARY MEDICINE AND SURGERY. 
and the character of the lameness, it was very evident that it ways 
of an inter-articular character, and this is a peculiar feature of this 
affection. Then, again, the reader must bear in mind that the jawi 
of animals do not dilate nor enlarge suddenly, nor make their ap- 
pearance aii at once, like a meteor in the regions of space, The 
affection is insidious, progresses in an almost imperceptible manner 
and usually escapes the notice of those who daily have charge of and 
handle the animal, us the following case, which is selected from 
among others, will serve to illustrate: 
A few years ago a gentleman purchased what then appeared as 
a fine family horse—a sorrel gelding, aged five years. About the 
beginning of March, one year after the purchase, in attempting to 
walk the animal from one stable to another, but a short distance 
off, he became suddenly lame in one of the hind limbs, low down, 
toward the foot, and it was found almost impossible to urge him 
forward, Finally, assistance was procured, and the animal had, 
literally, to be carried into a stable. Our services having been 
secured, we visited the sufferer, and found him standing on three 
regs, the near hind one being placed resting on the toe. The parts 
around the coronet were hot, and the patient was very unwilling 
to have the parts handied. He seemed to suffer much pain, was 
breathing hurriedly, and the pulsations were quick and wiry. The 
near approach of any person seemed to terrify the animal, and he 
actually trembled, from fear and pain, when urged to move. On 
making an examination of the jaws, we found that both angles 
of the lower jaw were enlarged to about two inches in thickness. 
This explained the nature of the sudden and otherwise mysterious 
lameness. The articulating surfaces of various bones, and the 
bones themselves, had become diseased, as is often the case in 
big jaw. The owner assured us that the horse had never before 
been lame, and he was very much surprised to find the lower jaw 
enlarged. 
Here the reader will perceive that the animal had been in the 
owner’s possession one year; had performed ordinary duty, yet 
was the subject of a gradua! enlargement of the jaw and a consti- 
tutional disease, which probably existed, yet in a slight degree, at 
the time of purchase. Hence we contend that the disease, in its 
early stages, is of a hidden or insidious character, and requires some 
tact and knowledge of the subject in order to detect it. 
Nature of the disease-—Big head and big jaw are ut one form 
