Disease as a threat to endangered species: Ethiopian wolves, domestic dogs and canine pathogens

Abstract

With increasing awareness of disease as an endangering process, an assessment of which pathogens might pose a problem and their patterns of infection in natural hosts is necessary. This paper examines the exposure of sympatric Ethiopian wolves (Canis simensis) and domestic dogs to canine distemper virus (CDV), canine adenovirus (CAV) and canine parvovirus (CPV) in the Bale region, Ethiopia and then relates these data to population trends of wolves. Wolves (n = 30) sampled between 1989 and 1992 had been exposed to CDV, CAV and CPV, but only CAV might be able to persist in this wolf population. Anecdotal and serological evidence suggested that an epidemic of CDV occurred in the dog population of the Bale Mountains National Park (BMNP) in 1992-93. All park dogs born since this time were seronegative to CDV, although some young dogs in the nearby urban population were seropositive. Despite evidence of CAV infection in wolves, none of the dogs sampled in the park were CAV seropositive, although this virus appeared highly seroprevalent and endemic in urban dogs. All dogs tested for CPV antibodies were seropositive. The BMNP wolf population declined in the late 1980s and early 1990s, with rabies responsible for a dramatic population reduction between 1990 and 1992. Although the population declined further up until 1995, it is not possible to assess whether the concurrent canine distemper epidemic in park dogs also affected wolves. Nevertheless, with evidence of rabies, CDV, CAV and CPV infections in sympatric domestic dogs and Ethiopian wolves, canid diseases clearly pose a significant threat to the future persistence of this Ethiopian wolf population.

Prevalence of Antibodies to Canine Parvovirus and Distemper Virus in Wolves in the Canadian Rocky Mountains

“…Very little is known about the relationships of CPV and CDV to human activity in North America compared to studies in African carnivores (Laurenson et al, 1998;Cleaveland et al, 2000). Our results suggest that this may be due to differences in disease ecology between the two continents.…”

“…For example, wolves (Canis lupus) and many other carnivores have the potential to be exposed to canine parvovirus (CPV) and canine distemper virus (CDV) not only from other wolves, but also from hosts such as domestic and feral dogs (Canis familiaris) and alternate hosts such as coyotes (Canis latrans) and red foxes (Vulpes vulpes; Laurenson, 1998;Cleaveland et al, 2000;Almberg et al, 2010). Prevalence of infection with carnivore pathogens such as CPV and CDV tends to increase among hosts in urban areas because of increased contact among individuals (Woodroffe et al, 2004), increasing spillover transmission rates from the reservoir hosts for wild canids (Steinel et al, 2001).…”

“…For example, Mainka et al (1994) found that domestic dogs were the main source of CPV and CDV infections in giant pandas (Ailuropoda melanoleuca) in China. Domestic and feral dogs have also been identified as the major reservoir hosts for CPV and CDV in Africa (Laurenson et al, 1998;Cleaveland et al, 2000).…”

An agent‐based movement model to assess the impact of landscape fragmentation on disease transmission

“…For some species, urbanization can lead to reduced home range sizes and territories that overlap more when compared to rural locations (Riley 2006). The resultant increase in contact rates can lead to changes in disease transmission patterns in urbanizing landscapes (Bevins et al 2012, Lee et al 2012; increased contact between wild and domestic animals in urban areas can also introduce novel disease (Williams et al 1988, Laurenson et al 1998.…”

Canine Parvovirus Enteritis, Canine Distemper, and Major Histocompatibility Complex Genetic Variation in Mexican Wolves

“…In recent years, it has become widely recognized that endangered species may be threatened by exposure to pathogens (Lyles and Dobson, 1993;Laurenson et al, 1998;Murray et al, 1999;Woodroffe, 1999;Lafferty and Gerber, 2002), some of them novel to the species. A pathogen introduced from a reservoir in a more common species, such as domestic animals, may result in final decline to extinction, particularly if the endangered species has low disease resistance.…”