Acute lethal leptospirosis in a red fox (Vulpesvulpes)

Area of Science:

• Veterinary Pathology
• Zoonotic Diseases
• Wildlife Epidemiology

Background:

• Leptospirosis is a widespread zoonotic disease affecting numerous animal species and humans.
• Red foxes (Vulpes vulpes) are increasingly common in urban and suburban environments.
• While Leptospira antibodies have been found in foxes, fatal disease was previously unreported.

Purpose of the Study:

• To document a case of fatal leptospirosis in a red fox.
• To characterize the gross and histological findings associated with the disease.
• To assess the potential role of red foxes in the epidemiology of leptospirosis.

Main Methods:

• Necropsy and gross examination of a deceased red fox.
• Histopathological analysis of tissues.
• Microscopic agglutination test (MAT) for Leptospira serovar identification.

Main Results:

• The fox exhibited jaundice, multifocal hemorrhages, hepatomegaly, splenomegaly, and renal discoloration.
• Histology revealed hemorrhages, vascular thrombi, interstitial nephritis, and gastric mucosal erosions.
• MAT identified a high titer to Leptospira interrogans serovar Icterohaemorrhagiae, suggesting contact with rats.

Conclusions:

• Fatal leptospirosis can occur in red foxes.
• The pathological findings are comparable to canine leptospirosis.
• Red foxes may serve as a reservoir and source of infection for Leptospira, posing a risk to other animals and humans.