Abstract
Comparative studies on the amyloid of several animal species were carried out to determine the different amyloid varieties by their specific staining properties and thus distinguish them from similar hyaline tissue structures. The material studied included cases of amyloidosis of the kidneys, liver and adrenal glands of cattle, renal amyloidosis of the dog and splenic amyloidosis of the mink. In addition, there were cases of amyloidosis of the vascular walls in Aleutian disease of mink and in mucosal disease of cattle as well as lymph node amyloidosis of the horse. On the basis of their organ and tissue location and their staining properties, the amyloid varieties of cattle, dogs, mink and horses were classified as amyloid and paramyloid. Typical amyloid stains green with Masson-Goldner, blue with azan and remains colorless with phosphotungstic acid-hematoxylin and Weigert's fibrin stain. Paramyloid, on the other hand, stains red with Masson-Goldner and azan, and blue with phosphotungstic acid-hematoxylin and Weigert's stain. Common features of the two amyloid varieties are congophilia, birefringence, color change to green with congo red staining, and fluorescence with thioflavin T staining.