To be sure, one observes an idiopathic chronic endo-arteritis in many abdominal arteries of the horse, which, however, never exhibits indications of atheromatous degeneration.
From a comparative pathologico-anatomical point of view, the developmental history of the aneurysma verminosum proves that a circumscribed endo-arteritis can determine the formation of an aneurism.
Arteritis may be limited to single trunks or it may affect, more or less, all the arteries of the body.
In acute arteritis we find swelling along the vessel, loss of elasticity, friability, and thickening of the walls; a roughness and loss of gloss of the inner coat, with the formation of coagula or pus in the vessel.
Arteritis may be acute, subacute, or chronic; when the inner coat alone is affected it is known as endarteritis.
Possibly syphilitic arteritis may be viewed as an entity, the cause is known and the lesions are characteristic.
Weber calls this case one ofarteritis obliterans with intermittent claudication.
As judged by lesions of the aorta and iliac arteries in dissecting subjects, the conclusion that arteritis and resultant disorders are of rather frequent occurrence, is logical.
The cause of arteritis is unknown in many instances, but parasitic invasion and contiguous involvement of vessels in some inflammatory injuries are etiological factors.
Changes in the arterial walls closely resembling those of syphilitic arteritis are sometimes met with in tuberculous lesions.
