Changes

Macroscopic lesions may include fibrinous peritonitis, broad multifocal mamillary necrosis and widespread intersitial pneumonia. Most organs are susceptible to ''L. monocytogenes''. Microscopic histopathology may include monocytic perivascular cuffing in brain tissues.

Macroscopic lesions may include fibrinous peritonitis, broad multifocal mamillary necrosis and widespread intersitial pneumonia. Most organs are susceptible to ''L. monocytogenes''. Microscopic histopathology may include monocytic perivascular cuffing in brain tissues.

===''Yersina'' Infections===

===''Yersina'' Infections===

Two species of ''Yersina'' have been isolated from chinchillas; ''Y. pseudotuberculosis'' and ''Y. enterocolitica''.

Two species of ''Yersina'' have been isolated from chinchillas; ''Y. pseudotuberculosis'' and ''Y. enterocolitica''. Both are types of gram-negative bacteria. Transmission is both via fecal-oral routes but also transplacental and milkborne. Infection can be asymptomatic but there is a high morbidity and mortality rate associated with infection. Clinical signs are consistent with other forms of bacterial infection such as those above.

Gross pathology associated with ''Y. pseudotuberculosis'' will often include granulomatous lesions primarily in the liver spleen and lungs. Gross pathology associated with ''Y. enterocolitica'' will cause similar lesions in these organs but also within the lymph nodes, intestines and kidneys.

===Iatrogenic (Antibiotics)===

===Iatrogenic (Antibiotics)===