SYMPTOMS OF N AVICULARTHRITIS. 157 



the cause of lameness not originating in inflammation — which as 

 yet has not had time to set in — it cannot be expected that heat 

 should be present. Neither will it be found in certain chronic 

 stages of the disease, wherein lameness is rather the consequence 

 of altered form and structure than of inflammatory action. Indeed, 

 in navicularthritic disease in general the inflammation present sel- 

 dom runs beyond what we call the suh-acute character ; and there- 

 fore does not give rise to any very great deal of preternatural heat 

 of hoof. Another circumstance accounting for the little heat that 

 is to be detected in navicularthritis is the thickness of substance, 

 and consequent distance, there is between the seat of disease and 

 part to which the hand can be applied — the wall of the hoof or 

 the sole ; the latter, after being pared out, being, in point of fact, 

 the nearest point to the navicular joint. After both soles have 

 been cleaned out, Mr. Turner informs us, he has generally de- 

 tected " an extra-proportion of heat in (that of) the lame foot :" 

 adding, — what I have not myself noted, — " the throbbing of the 

 pastern arteries is a more important criterion." Usually, also, 

 there is some augmentation of heat, and of fulness with it, to be 

 perceived around the coronet : a S34'nptom that seems natural 

 enough when we come to reflect on the vascular composition of 

 the coronary substance — on the quantity of blood it must always 

 contain, even when the foot is in health, and to what extent that 

 quantity is likely to become augmented under disease. The ful- 

 ness around the coronet will account for the appearance of sinking 

 or falling-in which the hoof of the lame foot presents. It will also 

 serve to explain the origin of the rimminess which the hoof in 

 after days is so likely to exhibit : the secretion of horn (which 

 takes place in the coronary substance) being naturally much influ- 

 enced under congested and inflammatory conditions of that vascu- 

 lar substance. 



Relapse. Careful inquiry should be made, and carried back 

 as far as it conveniently can be, with a view of ascertaining 

 whether the present be a first or second or third attack of lameness 

 in the same foot, and whether or not any thing of the kind has 

 ever happened to the opposite fore foot : the very circumstance of 

 relapse, from the known tendency of navicularthritis to return, 

 adding important weight in the consideration of symptoms, to say 



