﻿IX, B, 3 Boynton: Kidney-ivorm Infestation of Swine 283 



gested that the immediate cause of death was from an internal haemorrhage. 

 The source of the haemorrhage was found to be from a large aneurysm of 

 the anterior mesenteric artery which had ruptured. This aneurysm is 

 represented in Plate III, fig. 2. The anterior end, a, lay in close proximity 

 to the posterior aorta. It measured 24 centimeters in length and 34.5 centi- 

 meters in circumference around the largest portion. Near the posterior 

 end there was a slight constriction, /, which may be considered as dividing 

 the lesion into two aneurysms, a large anterior and a small posterior; how- 

 ever, the constricted portion was not composed of normal tissue. The 

 tunica adventitia was markedly roughened by outgrowths of fibrous connec- 

 tive tissue and nodules. These nodules (Plate III, fig. 2, e, and fig. 3, 

 a and b), of which 11 were easily seen on the surface of the specimen, were 

 composed of fibrous connective tissue. They protruded above the surface 

 on an average of 0.6 centimeter, and varied from 0.5 to 0.9 centimeter in 

 diameter. The longest nodule measured 3.5 centimeters in length, and 

 formed a tortuous course. The majority were about 1.5 centimeters in 

 length, giving them an oval appearance. These nodules either contained 

 kidney worms (Plate III, fig. 3, a), in which instance a worm can be seen 

 projecting from the cut end of a nodule, or they were filled with a mass 

 of cheeselike material. The tunica adventitia was very thin, being made 

 up of merely a superficial layer of connective tissue in places. The endo- 

 thelial lining and tunica intima had entirely disappeared and their places 

 were taken by a thick layer of fibrinous material varying from 0.3 to 2.6 

 centimeters in thickness, which coated the entire aneurysm. This fibrinous 

 material (Plate III, figs. 2, c, and 3, c) was yellowish white, firm in consis- 

 tence, and tough, thus forming a protective coat over the inner surface of 

 the aneurysm. 



A large parietal thrombus was present in the aneurysm (Plate III, fig. 4), 

 Two kidney worms were embedded in this thrombus, b and lb, and one worm 

 was found with its body partially protruding into the cavity of the aneurysm, 

 a portion of the body still remaining embedded in the wall. These facts 

 show that the kidney worm is capable of working its way through the wall 

 and into the lumen of a blood vessel. 



The appearance of the lesion just described suggests that by pene- 

 trating the wall of an artery the kidney worm is capable of producing 

 an inflammation of the muscular coats, which may cause them to lose their 

 tone. As a result of the constant high blood-pressure and weakened vessel 

 walls, they were stretched and unable to regain their normal size, the 

 ultimate result being the formation of the aneurysm. The heavy coating 

 of fibrinous coagulated material undoubtedly arose from the endaortitis, 

 which may have been caused directly by the irritating effect of the worms 

 upon the endothelial layer or by the extensive stretching of the weakened 

 muscular walls of the blood vessel. 



The aneurysm thus formed corresponds in many ways with the aneurysm 

 found in horses infested with Strongylus armatus (Sclerostoma equinum). 

 In the horse, the immature worm causes the aneurysm while in kidney- 

 worm infestation mature worms were found. 



In this animal, there was a generalized infestation. Worms were found 

 both free and encysted in the thoracic and peritoneal cavity. Three worms 

 were found in the right kidney, 2 of which were coiled in the calix and 1 

 embedded in the medulla. 



