Drivers of canine distemper virus exposure in dogs at a wildlife interface in Janos, Mexico.

BACKGROUND: Human population expansion has increased the contact between domestic animals and wildlife, thereby increasing the transmission of infectious diseases including canine distemper virus (CDV). Here, we investigated the risk factors associated with CDV exposure in domestic and wild carnivores from the Janos Biosphere Reserve (JBR), Mexico. METHODS: A cross-sectional household questionnaire study was performed in four rural towns to investigate the risk factors associated with the presence of CDV in domestic and wild carnivores from the JBR, Mexico. In addition, we tested serum samples from 70 dogs and three wild carnivores, including one bobcat (Lynx rufus), one striped skunk (Mephitis mephitis) and one gray fox (Urocyon cinereoargenteus) for CDV antibodies using immunochromatographic and viral neutralization assays. RESULTS: Overall, 62% of domestic dogs were seropositive for CDV, and the presence of antibodies was significantly higher in free-roaming owned dogs than dogs with restricted movement. Among the wild carnivores, only the bobcat was seropositive. The rate of vaccination against CDV in dogs was low (7%), and there was a high rate of direct interactions between domestic dogs and wild carnivores. CONCLUSION: Our serological assays show that CDV is circulating in both domestic dogs and wild carnivores, suggesting cross-species transmission. Our finding of low vaccination rates, high number of unrestrained owned dogs and direct interactions between wildlife and domestic animals reported in the region may be perpetuating the high prevalence of the virus and increasing the risk of CDV transmission between wild and domestic carnivores. Therefore, long-term longitudinal studies are recommended in order to monitor infectious diseases at the domestic-wildlife interface in this highly biodiverse region.

Parasitologic examination and associated risk factors of domestic dogs at the domestic-wildlife interface in the Iberá wetlands Ecoregion, Argentina.

The wildlife-domestic interface represents points of contact between wild animals and human-associated domestic animals, and provides opportunities for the dissemination and transmission of parasitic agents. Domestic dogs are reservoirs of parasitic agents, many of which are capable of infecting wild animals. To better investigate this potential risk at the Iberá wetlands eco-region, fecal samples from dogs present at the wildlife-domestic interface of two protected areas in Corrientes province, Argentina were examined. The prevalence of intestinal parasites and overall generic richness were examined and associations with age, sex, body condition, anthelmintic treatments and dog movement restriction were explored. From August-September 2017, questionnaires were carried out and fecal samples collected from 51 dogs at the interface zones. The overall estimated prevalence of gastrointestinal parasites was 63%. Nine genera of helminths and four protozoans were found in the examined dogs, many of which are known to infect wild carnivores and several have zoonotic potential. Ancylostoma and Isospora were the most prevalent genera. Freedom to roam was positively associated with prevalence and richness. From all dogs in our study, only a small proportion (17%) is subjected to some degree of movement restriction, while most dogs were free roaming. Veterinary health care and treatment was also extremely limited. The findings of this study revealed conditions of high prevalence of gastrointestinal parasites, lack of veterinary care and unrestricted roaming; all circumstances that suggest that dogs that live at these interface zones pose an infection risk to sympatric wildlife.

Carriage of pathogenic Leptospira in carnivores at the wild/domestic interface.

The carriage of pathogenic Leptospira was investigated by PCR in 51 wild carnivores, 20 domestic dogs with outdoor access, and 27 free-roaming domestic cats sampled in periurban Barcelona (NE Spain). Overall prevalence was 7.7%, with DNA confirmed in 3/30 common genets (Genetta genetta) (serovars Icterohaemorraghiae and Sejröe), 1/9 red foxes (Vulpes vulpes) (Canicola) and 2/27 cats (Icterohaemorraghiae). Though most of the dogs were vaccinated against Leptospira, DNA of the serovar Canicola was detected in the urine of 25% of the vaccinated animals, and the serovar Icterohaemorraghiae in one non-vaccinated dog.

Carnivore Protoparvovirus 1 at the Wild-Domestic Carnivore Interface in Northwestern Mexico.

Eighty-three wild and domestic carnivores of nine species from Janos Biosphere Reserve (JBR), Mexico, were tested by serologic and molecular assays to determine exposure and infection rates of carnivore protoparvovirus 1. Overall, 50.8% (33/65) of the wild carnivores and 100% (18/18) of the domestic dogs tested were seropositive for Canine protoparvovirus 1 (CPV), while 23% (15/65) of the wild carnivores and 22.2% (4/18) of the domestic dogs were PCR positive for CPV. Phylogenetic analysis confirmed circulation of CVP-2 with residues 426 Asn (CPV2a = 1/19) and 426 Glu (CPV-2c = 18/19) among carnivores in JBR. The prevalence of both PCR positivity and antibodies to CPV varied significantly among wild host species. Of the six identified haplotypes, three were unique to kit foxes (Vulpes macrotis) (the species with higher haplotype richness) and two to striped skunks (Mephitis mephitis). The remaining haplotype was shared among all carnivore species including dogs suggesting non-host specificity and bidirectional and continuous viral transmission cycle in the JBR. The phylogenetic similarity of CPV strains from dogs and wild carnivores and the higher prevalence of CPV in wild carnivores captured near towns relative to those captured far from towns suggest that dogs might be an important source of CPV infection for wild carnivores in the JBR. We provide evidence that cross-species transmission occurs at the domestic-wildlife interface in JBR.