154 DISEASES OF DOMESTICATED BIRDS 
been demonstrated that they are found in a large number of natural 
foodstuffs. They are very common in the seeds of plants such as 
cereals. In these, the vitamines are mainly deposited in the germ 
or embryo and to a less extent in the bran. White wheat flour is 
deficient in vitamines and is capable of producing polyneuritis. 
The facts observed during experimentation on fowls in connection 
with the study of the etiology of beri beri of man, suggest the possi- 
bility that in isolated instances, leg weakness of chickens may be 
induced by a similar cause. 
LIMBERNECK 
Limberneck is a symptom resulting from partial or complete loss 
of control of the muscles of the neck. Probably various causes such 
as digestive disturbances, intestinal parasites and the eating of 
spoiled meat may cause this symptom. Feeding on maggots from 
decaying meat will cause limberneck. 
According to Dickson, chickens when fed botulinus toxin, become 
dull and inactive, refuse to eat, remain quiet in one place with the 
feathers ruffled. They gradually develop weakness of the legs, wings 
and neck so that they are unable to stand. The wings droop and the 
beak or the side of the head rests upon the floor of the cage. Death 
occurs within 24 hours after feeding. 
Treatment consists of administering castor oil. Preventive meas- 
ures should include precautions against allowing birds access to de- 
caying meat. 
DISEASES OF THE ALIMENTARY TRACT 
PIP 
The condition commonly termed “ pip” does not represent a spe- 
cific disease, but is usually found associated with avian diphtheria. 
When the nasal passages become closed by the presence of mucous 
secretion or exudate, the fowl is compelled to breathe through the 
mouth. The constant passage of air over the tongue tends to dry 
and harden it at the tip. The dry, horny covering contracts and 
presses upon the soft tissues beneath, causing the fowl much annoy- 
ance. The hardened layer may partially separate from the soft 
tissues and expose a raw, inflamed surface. The practice among 
some poultrymen of removing the horny tip should be discouraged 
since it only increases the discomfort of the fowl by leaving a raw, 
sensitive surface exposed to foreign irritants and microorganisms. 
