48 HEALTH AND DISEASE 



stiffness in the muscles of the head and neck may be observed. The 

 animal exhibits some ditiiculty in grasping its food, and in most cases the 

 muscular spasm rapidly increases, and the animal is incapable of moving 

 the head and neck. The jaws are locked or brought forcibly together, 

 the tail is elevated, and the legs are stiff and abducted. In this condition 

 any sudden alarm produces an accession of the spasm, and in the horse 

 a characteristic symptom is the sudden retraction of the eye into its orbit, 

 and the thrusting forward over it of the nictitans membrane (haw). In 

 the acute form of tetanus the spasm is perceived to extend rapidly along 

 the muscles of the back, loin, and tail, and to the muscles of the ex- 

 tremities, which are commonly spread out, and are only moved with 

 difficulty. The respiration is always laboured in consequence of the 

 affection of the respiratory muscles, and the nostrils are widely dilated. 

 The surface of the body is commonly covered with perspiration. The 

 duration of the disease varies, according to the acuteness of the attack, 

 from three or four days to several weeks, but the majority of fatal cases 

 terminate within a week. In cases which recover, the muscular stiffness 

 may continue for several weeks, gradually becoming less until it entirely 

 ceases. Generally it may be said that should the animal survive the 

 ninth day recovery is rendered probable. 



Chronic Tetanus is indicated by a less defined spasm, which com- 

 monly remains limited to the head and neck; in many cases the animal 

 retains a certain power over the muscles of mastication and can take soft 

 food. 



Post-Mortem Appearances. — There are no very important changes 

 recognized in the nerve centres or in the nerve fibres beyond slight con- 

 gestion, which sometimes is apparent in the nerves proceeding from the 

 wound. The blood is dark in colour, and there are patches of blood- 

 coloured exudation under the serous and mucous membranes. The lungs 

 are usually congested, sometimes in a state of gangrene. Commonly the 

 muscles are very dark in colour, and are marked with patches of blood- 

 coloured exudation here and there. 



Treatment. — Absolute quietude experience has proved to be essential. 

 The late Professor Spooner used to advise his students to lock the stable 

 door and take possession of the key, and this cannot be regarded otherwise 

 than as excellent advice. Where an animal offers no resistance it is desir- 

 able that he should be slung to prevent the injury which results fi'om his 

 struggling to maintain the erect position. When the patient can masticate, 

 any kind of green food or cooked food may be given, otherwise the diet 

 will have to be restricted to gruel, or meat soup thickened with meal, and 

 at all times cold water should be within the, animal's reach. The surface of 



