Vaccine-induced distemper in domestic ferrets (Mustela putorius furo): 5 cases (2022)

Background

Canine distemper virus (CDV) is a highly contagious disease that has been reported in several mammals, including the domestic ferret (Mustela putorius furo). Vaccine-induced disease occurs when modified liver virus (MLV) vaccines are used.

Methods

A retrospecitive review of medical records and pathology reports from a single academic institution for 2022, was performed. All ferret cases that had CDV histopathology findings and positive CDV RT-PCR were included.

Results

Five cases were identified. Data was extracted from the available records/forms. Cases were presented between September and December of 2022 and included 2 castrated males and 3 unknown sex animals. (11-to 29-weekd old) from Oklahoma (n=4) and Virginia (n=1). All animals had clinical signs of CDV, originated from the same breeding facility, and were allegedly vaccinated with a commercially available MLV-CDV vaccine for mink. Histopathological findings were consistent with CDV< and brain and/or lung tissue was CDV positive by RT-PCR. H-gene sequencing identified America-1 strain/Lederly-CDV3-like genetic material with 99% identify with the vaccine. H-gene sequences showed that the CDV strains formed a separate clade in the tree within the Lederle group. The M-F regions were 100% identical to the MLV-CDDV vaccine.

Conclusions and clinical relevance

Based on sequencing, ferrets were infected with a CDV Lederle-like strain, which is believed to be extinct in the wild. The findings of these cases share several similarities to previous reports of vaccine-induced disease. MLV vaccines should be avoided for immunization of ferret kits, especially in settings like breeding facilities and pet stores, where epidemiologic risks are amplified.