Symiatoms. Treatment. 757 



Symptoms. Tlie disease occurs in a very pronounced form 

 in dourine (see Vol. I). In cases caused by chronic lead poison- 

 ing there is generally only paralysis of the pharynx, esophagus 

 and larynx, acceleration of the pulse, constipation, and some- 

 times symptoms of colic (Thomassen). It is not, however, quite 

 certain that in many cases there are not symptoms of motor 

 disturbance. In Vachetta's case already mentioned there was 

 obvious extensive paralysis, the fowl was scarcely able to stand 

 and simply squatted. The polyneuritis seen in cases of dourine 

 not rarely disappears Avithout any sequel, but the disease oc- 

 curring in cases of chronic lead poisoning generally terminates 

 fatally owing to pneumonia caused by foreign bodies. 



In polyneuritis of the fowl due to feeding with rice, the gait 

 becomes unsteady, especially when the bird is on a perch, "for it is 

 obvious that if the bird cannot grip sufficiently tightly with the toes, 

 it must exert itself to keep from falling." The birds are not 

 able to get up on their perches, but stand with the legs wide apart, 

 the joints flexed. During movement, the limbs often give way, caus- 

 ing the bird to fall. In the late stages, the birds cannot even stand. 

 The muscles of the wings, body, and neck are paralyzed; there is great 

 emaciation, respiration becomes difficult, and the birds die in five to 

 ten days. In peracute cases death may take place in two to three 

 days. 



In polyneuritis of the cock, there is a gradually increasing weak- 

 ness of the feet; movement becomes more and more difficult, the legs 

 give way under the weight of the body and the birds collapse. As a 

 rule, the legs give way in such a manner that the whole length of 

 the posterior surface of the metatarsus is in contact with the ground. 

 Power of copulating is lost from the outset. In the later stages, there 

 may be complete paralysis of the wings, body, and neck. The course 

 of the disease extends over several weeks. There appears to be no 

 complete recovery. In one cock the paresis lasted unchanged for two 

 years, until death took place from some other cause. 



Treatment. The treatment of dourine has been dealt with 

 elsewhere (see Vol. I). In cases of chronic lead poisoning po- 

 tassium iodide should be administered internally, the pasture 

 or food should be changed or the animal should be moved 

 elsewhere in case the food may be the vehicle of the poison. In 

 cases of polyneuritis caused by rice improvement follows a 

 change of food provided it be made early enough. 



Literature. Kellermann, A. L., 1907, 631.— Marek, D. t. W., 1901, 417 (Lit. 

 on polyneuritis of chickens). — Thomassen, Monatsschr. f. Psych, u. Neurol., 1903, 

 423.— Vachetta, N. Ere, 1907, 257. 



17. Trotting Disease of Sheep. 



{Traherl-rcnikJieit [German], Treinhhutte [French].) 



Occurrence. This disease, which was practically unknown 

 previously, has occurred with much greater frequency since the 

 end of the eighteenth century. This coincides with the intro- 



