Safety of and serological response to a new canine distemper‐parvovirus combination vaccine in domestic ferrets

Background Pet ferrets are typically vaccinated against distemper using a canine multivalent vaccine despite the lack of relevant safety or efficacy data. Here, we investigate the safety of a novel live canine parvovirus type 2c (CPV‐2c) vaccine strain and the efficacy of the live Onderstepoort canine distemper virus (CDV) vaccine strain used in a new bivalent vaccine. Methods Following an overdose of the CPV‐2c component to 16 ferrets, blood, faeces and various tissues were tested to investigate viral dissemination and shedding. Serum antibody concentrations were also measured. Long‐term serology of the CDV component was assessed in five ferrets vaccinated twice with a field dose of vaccine. Three of the ferrets were given a booster dose of the same vaccine after 1 year. Results Despite responding serologically to the CPV‐2c component, there was no evidence of any dissemination or shedding of the virus. A strong CDV antibody response was seen, which remained above protective levels for 2 years irrespective of whether the animals received a booster. Limitations Although the CDV serology results were consistent, these were from a small number of animals. Conclusions This CPV‐2c vaccine strain appears unlikely to disseminate or be shed following administration in ferrets. Vaccination with the combined CDV‒CPV vaccine should protect ferrets against distemper for at least 2 years.