620 THE HORSE. 
there can be no doubt. The dread of water, as well as of draughts of 
cold air, is also clearly made out to exist in this disease (as in human 
rabies), and the term hydrophobia will serve to distinguish it better than 
in the dog, where it is as clearly absent. Whenever, therefore, these 
symptoms follow upon the bite of a dog, unless the latter is unquestion- 
ably in good health, rabies may be suspected, and the bare suspicion 
ought always to lead to the use of the bullet, which is the safest way of 
killing a violent horse. There is only one disease (phrenitis) with which 
it can be confounded, and in that the absence of all consciousness and, in 
milder cases, of fear, so that no moral control whatever can be exercised, 
marks its nature, and clearly distinguishes it from rabies, the victim to 
which is conscious to the last, and though savage and violent in the 
extreme, is aware of the power of man, and to some extent under his 
influence. 
TETANUS—LOCK JAW. 
Tetanus, one form of which is known as lock jaw, has its seat appa 
rently in the nervous system, but like many other diseases of the same 
class, the traces it leaves behind are extremely uncertain, and are displayed 
more on the secondary organs, through which it is manifested, than on 
those which we believe to be at the root of the mischief. Thus the 
muscles, which have been long kept in a state of spasm, show the marks 
of this condition in their softened and apparently rotten condition. They 
in fact have had no interval of rest, during which nutrition could go on, 
and have lost much of the peculiarity of structure which enables them to 
contract. The stomach often shows marks of inflammation, but as all 
sorts of violent remedies are employed, this may be due to them rather 
than to idiopathic disease. ‘The lungs also are generally congested, but 
here, like the state of the muscles, it may be a secondary effect of the 
long-continued exertions of the latter, which nothing but the absence of 
all important lesions of the brain and spinal cord would induce the 
pathologist to pay the slightest attention to. 
TeTanus may be either idiopathic or symptomatic, but the former 
condition is somewhat rare. It almost always follows some operation, or 
a severe injury in which a nerve has been implicated, the most frequent 
causes being the piercing of the sole by a nail, or a prick in shoeing, or 
the operations of docking, nicking, castration, Wc. 
THE SYMPTOMS are a permanent rigidity of: certain voluntary muscles, 
and especially of the lower jaw (whence the popular name, lock jaw). 
The mouth is kept rigidly shut, the masseter muscles feelfng as hard as a 
deal board. One or both sides of the neck are rigid, in the former case 
the head being turned to one side, and in the latter stretched out as if 
carved in marble. ‘The nostrils are dilated; the eyes retracted, with the 
haws thrust forward over them; the ears erect and stiff, and the counte- 
nance as if horror-struck. At first the extremities are seldom involved, 
but as the disease progresses their control is first lost, and then they 
become rigid, like the neck and head. ‘The patient is scarcely able to 
stand, and plants his feet widely apa.t to prop himself up, while at last 
the tail also becomes a fixture. The pulse varies a good deal, in some 
cases being quick, small, and hard, and in others slow and laboured. 
The bowels are generally costive, and the urine scanty; but this last 
symptom is not so well marked as the state of the bowels alluded to. 
The treatment should be of a two-fold nature, partly palliative and partly 
curative. Since the introduction into use of chloroform we have possessed 
