What describes the lesions produced by FIP?

Feline Infectious Peritonitis (FIP) is characterized by specific types of lesions that are significant in its pathology. The disease is caused by a mutation of the feline coronavirus and typically leads to two forms: wet (effusive) and dry (non-effusive).

In the case of the dry form, the lesions are primarily granulomatous. Granulomas are organized collections of macrophages that have transformed into epithelioid cells, often associated with chronic inflammation. In addition to this granulomatous inflammation, lesions can also exhibit areas of necrosis and fibrinous exudate, along with mononuclear cell infiltration.

This granulomatous response reflects the immune system's reaction to the viral infection and results in distinctive clinical signs, which may include organ involvement, particularly in the liver, kidneys, and lymph nodes. The ability to identify these lesions pathologically is essential for diagnosing FIP, especially in the absence of other systemic signs.

In contrast, abscesses typically represent localized collections of pus due to bacterial infection and have different histological features, while purulent lesions are characterized by neutrophilic infiltration predominantly associated with bacterial infections. Hemorrhagic lesions are indicative of different pathological processes like vascular compromise or coagul