104: VETERINARY MEDICINE AND SURGERY. 



at different intervals. Or concussion and pressure, such as that produced 

 by a blow or fall, may bring on similar effects. From such causes the 

 blood-vessels may even give way in the brain, and death may be the im- 

 mediate result, or sensibility may be lost and a state of perfect coma may 

 ensue. 



Sunstroke or the effect of powerful sun and heat, especially on an 

 animal in a plethoric state, may bring on affection, usually comatose, of 

 the brain. 



Symptoms. — Williams thus describes the symptoms: — The animal 

 at first appears dull, listless, falls asleep whilst standing, or drowsily 

 nods its head; eats slowly and at intervals; the breathing is generally 

 slower than is natural, sometimes slightly accelerated, but it is always of 

 a somewhat snoring description. The pulse is also slower than natural, 

 from twenty-six to thirty, full and rolling. When made to walk, it has 

 a straggling gait, staggers, and seems as if about to fall. If suddenly 

 disturbed whilst in the somnolent condition, it looks around excitedly, 

 shivers violently, and seems affrighted; but soon becomes calm again, 

 and may remain so for a short period, especially if kept in a dark, quiet 

 place. It now and then thrusts its head against the rack or wall of the 

 stable; moves the limbs automatically; rears, hangs back, and breaks the 

 halter, or gets its forefeet into the manger, and elevates the nose high 

 up into the rack. The eyes, mouth, and rectum are injected, and of a 

 yellow tinge. In some cases, the yellowness of the mucous membranes 

 is a very prominent symptom. As the disease advances, the extremities 

 become alternately hot and cold; sweats bedew the body; there will be 

 twitchings or clonic spasms of the superficial muscles of the neck, breast, 

 and hind quarters. Violent convulsions will now occur; the whole body 

 becoming stiff and rigid, and the respiratory movements extremely diffi- 

 cult. During these spasmodic — tonic — attacks, the tail will be elevated, 

 the membrana nictitans drawn over the eye, as if the animal were suffer- 

 ing from tetanus, and the pulse frequent, hard, and wiry, the eyes fixed 

 and amaurotic, the mouth clammy, and the urine may be ejected by a 

 convulsive effort. All at once the tonic contractions subside, and there 

 will be great muscular debility; the legs bend, the animal totters, some- 

 times falls, and when down will fight convulsively, and for a time be 

 unable to rise. By slow degrees consciousness to some extent returns; 

 the animal may then regain its feet, and will perhaps commence to feed; 

 then fall asleep, with its mouth full of food, or look about in a wild, 



