title: Dog overpopulation and burden of exposure to canine distemper virus and other pathogens on Santa Cruz Island, Galapagos.
abstract: Dog overpopulation and diseases are hazards to native island species and humans on the Galapagos. Vaccination and importation of dogs are prohibited on the Galapagos. Risk management of these hazards requires the use of science-based risk assessment and risk communication. The objectives of the study reported here were (i) to estimate the human:dog ratio and (ii) the prevalence of and identify exposure factors associated with positive antibody titers to canine distemper virus (CDV) and other pathogens, as well as infection with intestinal parasites in owned dogs on Santa Cruz Island, Galapagos in September 2014. The observed human:dog ratio was 6.148:1 which extrapolates to 2503 dogs (two times more than a recent dog count conducted by Galapagos Biosecurity Agency in March 2014). The proportion of spayed female dogs (50%) was higher, compared to neutered male dogs (30%) (p=0.04). Prevalence of dogs with positive antibody titers to CDV was 36% (95% CI=26, 46%), to canine parvovirus was 89% (95% CI=82, 95%), and to canine adenovirus was 40% (95% CI=30, 51%). The frequency of seropositive dogs to CDV was lower in urban dogs (26%), compared to rural dogs (53%) (p<0.05). A positive interaction effect between rural residence and spay/neuter status on seropositivity to CDV was observed, which we discuss in this report. Because vaccination is prohibited, the dog population on Santa Cruz is susceptible to an outbreak of CDV (particularly among urban dogs) with potential spill over to marine mammals. Dog's age (1-2 or 3-14 years old, compared to younger dogs), and residence (rural, urban) were associated with positive antibody titers to parvovirus, adenovirus, Ehrlichia spp., or Anaplasma spp., as well as infection with Ancylostoma spp., an intestinal parasite in dogs that can be transmitted to humans, particularly children. These results provide the most comprehensive assessment of dog overpopulation and exposure to CDV and other pathogens on the Galapagos to date.
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0136, USA.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Diaz
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0136, USA.
authors.forename: Gabriella S
authors.initials: GS
authors.lastname: Mendez
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0136, USA.
authors.forename: C Jaime
authors.initials: CJ
authors.lastname: Grijalva
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0136, USA.
authors.forename: Heather S
authors.initials: HS
authors.lastname: Walden
authors.affiliation: Agencia de Regulación y Control de la Bioseguridad y Cuarentena para Galápagos, Santa Cruz, Galápagos, Ecuador.
authors.forename: Marilyn
authors.initials: M
authors.lastname: Cruz
authors.affiliation: Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Aragon
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0136, USA. Electronic address: hernandezja@ufl.edu.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Hernandez
mesh_terms: D000818:Animals; D004216:Distemper / Q000453:epidemiology* / Q000821:virology; D004217:Distemper Virus, Canine / Q000276:immunology*; D004283:Dog Diseases / Q000453:epidemiology* / Q000382:microbiology / Q000469:parasitology / Q000821:virology; D004285:Dogs; D004484:Ecuador / Q000453:epidemiology; D005260:Female; D008297:Male; D010273:Parasitic Diseases, Animal / Q000453:epidemiology / Q000382:microbiology / Q000469:parasitology / Q000821:virology; D011156:Population Density; D015995:Prevalence
keywords: Canine distemper virus; Canine ecology; Diseases; Dogs; Galapagos; Prevalence