Salmonellosis in Wildlife: Diagnosis, Prevention, and Treatment Options for the Zoo Veterinary Technician and Wildlife Rehabilitator

Abstract

Salmonellosis is a common worldwide disease that can affect all animals, including humans. The primary mode of transmission is through direct oral ingestion of contaminated feces or through contaminated food sources. Salmonellae are small, straight, Gram–negative rods whose many serotypes fall into two main categories: those highly adapted to a specific host and those with broad host ranges. The incidence of salmonellosis has increased with the intensification of livestock production where animals are abnormally crowded and stressed. Under these conditions fecal contamination of skin or food supplies can occur. Although these situations rarely occur in natural settings, it is important to note that zoos and rehabilitation facilities can render similar stressful situations. Clinical salmonellosis manifests as primary enteritis and colitis, generalized infection (septicemia), or abortion, and can occur in all stages from peracute to chronic. A positive diagnosis of salmonellosis is based on a fecal culture of the bacteria and observed clinical signs. Salmonella spp. can be spread from wildlife to humans by improper handling of infected animals and is considered a Class 4 nosocomial pathogen. Conversely, there are documented cases in Antarctica and Africa where increasing ecotourism has resulted in higher incidences of salmonellosis in native wildlife. Clinically ill animals can be treated cautiously with an antibiotic and receive supportive care but, in severe cases, the prognosis is guarded. Use of the existing list of recommended husbandry and hygienic actions, along with the ability to detect the signs, will decrease the spread of salmonellosis in wildlife facilities and zoos to those animals under care as well as to the practitioners.