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 laminae 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. 



Fig. 129.— Diagram illustrating Position of Seedy-Toe 

 (Internal). 



i, The horn of the wall; 2, the horn of the sole; 3, the cavity of 

 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 



