426 VEDDER AND CLARK. 



when the spasticity is severe, the fowl topples forward as the 

 result of this interference of the legs. 



Retraction of the head. — This is a frequent symptom in the 

 later stage of the disease. The anterior groups of muscles in the 

 neck become paralyzed, and the continued action of the posterior 

 groups retracts the head far backward. This overbalances the 

 fowl so that it is unable to sit upon its paralyzed legs. If a 

 fowl in this condition is placed upon its legs in a squatting posi- 

 tion, it makes several spasmodic efforts to retain its equilibrium, 

 and finally topples over backward. Such a fowl is unable to rise 

 without help. 



Dysphagia. — After the fowl becomes so paralyzed that it is 

 unable to arise, dysphagia almost always sets in. The fowl 

 appears to be totally unable to swallow normally, and when water 

 or medicines are administered they run out of the mouth when 

 the bird is laid down, unless care is exercised to prevent this. 

 It is also very easy to choke such a bird by attempting to revive 

 it by hand feeding. 



Respiration. — The respiration of the fowl suffering from an 

 advanced stage of the disease is slower and deeper than normal. 

 As the bird lies on its side, its abdomen may be observed to 

 expand and contract slowly almost like a pair of bellows. 



Sensory symptoms. — It is somewhat difficult to obtain accurate 

 information with regard to the sensory changes. But by tap- 

 ping, pinching, and pricking the legs, and comparing the reaction 

 with that obtained in normal fowls, it is apparent that sensation 

 is much reduced in the legs of birds suffering from polyneuritis, 

 and it is believed that this loss of sensation precedes slightly the 

 motor paralysis. It is possible that the peculiar high-stepping 

 gait described above may be the result of sensory disturbance. 



Loss of weight. — Progressive loss of weight was an almost 

 constant symptom. Thus of 20 fowls fed on polished rice, whose 

 weights were carefully recorded, the average weight at the begin- 

 ning of the experiment was 3.15 pounds. The average weight 

 of these same fowls taken on the date when the first symptoms 

 of polyneuritis appeared was 2.45 pounds. This represents an 

 average loss of 0.7 pound, or 22 per cent, of their original body 

 weight. A few fowls, however, developed neuritis although they 

 lost comparatively little weight. Thus one fowl whose original 

 weight was 3 pounds 1 ounce developed neuritis after a loss of 

 only 8 ounces, and several fowls lost only 5 ounces. 



This loss of weight is such a constant observation, that the 

 view has been held that polyneuritis of fowls is simply the result 

 of inanition which is expressed by this loss of weight. That this 



