Amyloidosis is a disease in which a proteinaceous amorphous, eosinophilic, hyaline material is deposited extracellularly. A 4 year old Abyssinian male cat manifested disease; formalin fixed tissues were processed by the hematoxylin – eosin technique and submitted to histopathological examination. The clinical history included gastrointestinal signs, behavioral changes and poor body condition. In the histopathological evaluation an eosinophilic irregular-shaped extracellular material located in renal glomeruli, in the Dissé space of liver and around the glands in the large and small intestines. Affected tissues stained with Congo red revealed a material with green birefringence when examined under polarized light. Colonic ulcers, peritonitis and vasculitis were also seen and could be related to the pathogenesis of the amyloidosis in this case.

The lipopolysaccharide (LPS) or endotoxin is the major component of the outer membrane in Gram negative bacterial pathogens; it plays an important role in the activation of the immune system to be the most important surface antigen of Gram negative bacteria. The LPS consist of a lipophilic component and a polysaccharide portion with different function that makes this molecule one of the virulence factors more complex to understand, this review make an approach to measure the diversity effects and universality of LPS.