270 TETANUS 



"ewe neck." The muscles of the neck become hard and tense 

 to the touch. 



4. The extensor muscles of the back. Spasms of these 

 muscles are manifested by an extremely hard condition of the 

 muscles of the back, loins and croup. Several conditions may 

 arise : orthotonous in which the neck is stretched out and the 

 back and croup are carried horizontally, or opisthotonous in 

 which the head is raised or drawn back and the vertebral 

 column slightly depressed. This is the most common occur- 

 rence. There may be a lateral curvature of the cervical verte- 

 brae which is uncommon and also a convex curvature of the 

 vertebrae which is very rarely observed. The tail, especially 

 in horses, is often raised and occasionally said to be straight 

 with the back. 



5. The muscles of the limbs. The spasms in these muscles 

 make the limbs stiff and cause the animal to assume an attitude 

 in which the fore legs are extended forward and laterally and 

 the hind ones backward and laterally. They are bent at the 

 joints only with difficulty. The contraction of the muscles of 

 the abdomen gives the animal a tucked up appearance and the 

 spasms of the muscles of respiration render breathing difficult. 



Besides the spasms the animal shows an increased reflex 

 irritability and heightened sensibility. These manifest them- 

 selves in excitement, timidity and intensified muscular con- 

 tractions if irritated. Sweating is common, especially in severe 

 cases. In mild cases it may be absent. There is usually 

 little or no change in the internal temperature. In fatal cases 

 the temperature is usually constantly high toward the last. 

 The high temperature (104° to 106° F.) usually continues for 

 some time after death. Bayer has observed in a horse, 24 

 hours before death, a temperature of 102° F. ; one and a half 

 hours before death, 105° F. ; at the moment of death, 111° F. ; 

 and fifty minutes after death, 113° F. There is frequently no 

 increase in the number of pulse beats until severe exacerba- 

 tion sets in. The frequency of the pulse is much greater in 

 animals which continue recumbent than in tho.se which keep 

 upon their feet. The pulse is often hard and small and the 



