508 CHAPTER 65. 



lameness will disappear, especially if the ground be soft. This is very 

 characteristic of the disease. 



A marked feature in navicular lameness is that the animal invariably 

 goes upon his toes in progression and is more lame in going downhill. 

 If lame in both fore-feet he will have a short pottering action. 



From the above it will be seen that the symptoms of navicular disease 

 are negative rather than positive. If the signs of the lameness are those 

 of foot lameness, and if after due examination no other adequate cause 

 can be discovered, we have reason to suspect navicular disease. 



In all cases of long standing the foot or feet become contracted. In 

 some cases the atrophy extends to the muscles of the shoulders and fore- 

 arm. This wasting away is due simply to the decreased use which the 

 horse makes of his fore-hand in action on account of the disease existing 

 in his fore-feet. 



1024. Cause. 



My attention was drawn some years ago to the very marked decrease of 

 cases of Navicular disease ; and about the same time to the very great 

 decrease of the practice of paring out the Sole and mutilating the Frog. 



The symptoms of Navicular disease, as given in par. 1023, are those 

 which must occur in the interior of the foot by the concussion and fric- 

 tion caused by the paring out of the sole, and the mutilation of that 

 " everlasting " pad known as the Frog. I have used a strong word, 

 because the Frog grows stronger and stronger the more it is thumped 

 about. Please turn to par. 952 (the Frog), and 1015 (latter part). 



The symptoms of Navicular disease in the interior of the foot are 

 exactly those which must occur from concussion and friction, when kind 

 nature's protection against concussion and friction is taken away. 



1025. Treatment. 



If the reader will turn to Plate 47, Fig. 10, he will at once see that 

 the mischief is in the very centre of the foot, and that outward applica- 

 tion, such as blistering or firing, can have no effect on the tendon running 

 under the navicular bone; nor can any external treatment arrest the 

 erosion of a bone in the centre of the foot, 



It has been suggested to pass a seton through the Frog. But it is 

 not easy to see in what way a seton could strengthen the tendon, or stop 

 the decay of the navicular bone. 



1026. Neurotomy. 



It has been suggested to unnerve the foot. Of course this would give 

 relief for some limited time, and cause apparent soundness. But as 

 greater force in action would be thrown on the already broken structure 

 in the interior of the foot, the apparent relief could not last long. 



There are cases on record where horses after being unnerved have 

 done excellent work for years. The answer is simple, viz. that the horse 

 was not affected by Navicular disease. 



Horses, which have been unnerved, are obviously unsafe off a level 

 turnpike road. 



