CORRESPONDENCE 
229 
of diseases witli more pain, such as pleuro-pneumonia. My ex¬ 
perience of pnrpura hsemorrhagiea with the abrupt termination 
of tlie swellings, petecliial spots on the Schneiderian membrane, 
as well as on other membranes, we get a slow, oppressed and 
double pulse, sometimes of an intermitting character, and only 
felt in the carotids, whilst the breathing is scarcely disturbed, 
unless when swellings run on to the throat: 
NAVICULAR DISEASE. 
By Mr. A. Zundel. (February No.) 
Navicular disease, till of late, seemed a mysterious one to the 
veterinary surgeon. 
I am sorry I cannot agree with Mr. Zundel as to the origin of 
this disease, when lie is of the opinion that it is the synovial 
capsule that is first attacked. Then I should like to know how is 
it that we have found the cancellated tissue of the navicular bone 
in its centre diseased, without any external appearance of ulcera¬ 
tion on its surface ? For, if the synovial capsule was the first 
diseased, I should expect the surface of the ifavicular bone next, 
and then its cancellated structure. 
In my opinion, the cancellated tissue is first attacked, which 
runs on to ulceration of the surface of the navicular bone, and by 
the deposits on its surface the synovial capsule and perforans 
tendon become diseased, and afterwards we have the several 
adhesions. 
Mr. Zundel says the animal is afraid to let his foot to the 
ground. If this was so, 1 should expect great pain on pressure at 
the heel—always a certain amount of fever—but this is not the 
case. 
All horses suffering from navicular disease point the foot, but 
not resting on the toe, as stated by Mr. Zundel, the heel being 
on the ground the same time as the toe. In strain of the back 
tendons, suspensory ligament, or muscle of the shoulder, the 
animal rests on his toe, but more under the shoulder, and not so 
much pointed as in navicular disease. In the former cases the 
limb is much more flexed. 
