294 DISEASES OF THE HORSE’S FOOT 
In these cases—cases with an insidious onset—we are 
inclined to the opinion that the disease of the horn com- 
mences from below, and that the sensitive lamine become 
implicated later. Holding this view, one must account for 
the commencing disease of the horn by giving, as causes, 
firstly, those factors (as, for instance, alternate excessive 
dampness and dryness) leading to disintegration of the 
horn tubules; secondly, the penetrating into and between 
the degenerated tubules of parasitic matter from the ground; 
and, thirdly, the final breaking up of the horn, and spread 
of the lesion under the invasion thus started. 
Fic. 129.—D1aGRam ILLUSTRATING PosITIoN oF SEEDY-TOE 
(INTERNAL). 
1, The horn of the wall; 2, the horn of the sole ; 3, the cavity of the seedy- 
toe; 4, the os pedis; 5, the keratogenous membrane. 
Symptoms.—Lameness sometimes attends seedy-toe, and 
sometimes does not. This is an important point to be 
carried in mind by the veterinary surgeon who is accus- 
tomed in his practice to have many animals pass through 
his hands for examination as to soundness. An animal 
with advanced seedy-toe—a condition constituting serious 
unsoundness-——may walk and trot absolutely sound, and 
may give no indication, either in the shape of the wall or 
the condition of the sole, that anything abnormal is in 
existence. Later, however, after the veterinary surgeon 
has passed him, the purchaser lodges the complaint that 
the horse has a bad seedy-toe, which, so he is told, must 
