Mycoplasma haemocanis (Mhc) is prevalent in the endangered Darwin9s fox (Lycalopex fulvipes) in its main stronghold, Chiloé Island (Chile). The origin of the infection, its dynamics, its presence in other fox populations and the potential consequences for fox health remain unexplored. During eight years, hemoplasmal DNA was screened and characterized in blood from 82 foxes in Chiloé and other two fox populations and 250 free-ranging dogs from Chiloé. The prevalence of Mhc in foxes was constant during the study years, and coinfection with Candidatus Mycoplasma haematoparvum was confirmed in 30% of the foxes. Both hemoplasma species were detected in the two mainland fox populations and in Chiloé dogs. Mhc was significantly more prevalent and more genetically diverse in foxes than in dogs. Two of the seven Mhc haplotypes identified were shared between these species. Network analyses did not show genetic structure either by species (foxes vs. dogs), geographic (island vs. mainland populations), or temporal (years of study) factors. The probability of infection with Mhc increased with fox age but was not associated with sex, season, or degree of anthropization of individual fox habitats. Some foxes recaptured with years of difference were infected with the same haplotype in both events and no hematological alterations were associated with hemoplasma infection, suggesting tolerance to the infection. Altogether, our results indicate that Mhc is endemic in the Darwin9s fox and that intraspecific transmission is predominant. Nevertheless, such a prevalent pathogen in a threatened species represents a concern that must be considered in conservation actions.

The presence of vector-borne pathogens of veterinary and public health interest have received little attention in Chile. In Easter Island, in particular, a Chilean territory in the southeastern Pacific Ocean, no information is available. To fill this gap, 153 rural dogs were inspected for ectoparasites during a sterilization campaign carried out in 2016. Fleas were observed in 46% of the dogs, and Ctenophalides felis (Bouché, 1835) was the only species present. Morphological identification of fleas was genetically confirmed using conventional polymerase chain reaction targeting the cox2 gene. No tick was observed in any dog. The presence of DNA of Rickettsia sp. (gltA and ompA fragment genes), Anaplasmataceae (16S rRNA), and Bartonella sp. (16S-23S ribosomal RNA intergenic spacer) was investigated in blood samples of 70 of the dogs and in 126 fleas analyzed in 68 pools that included 1–5 fleas. Rickettsial DNA was detected in 97% (n = 66) of the flea pools. Of these, 57 showed between 99 and 100% identity for both genes with published sequences of Candidatus Rickettsia asemboensis (CRa), six with Rickettsia felis, and one with Candidatus Rickettsia senegalensis. For two pools, gltA amplicons were identical to CRa but ompB amplicions showed 99–100% identity with R. felis. Anaplasmataceae DNA was detected in 16% (n = 11) pools. Sequenced amplicons showed highest identity with the endosymbiont Wolbachia pipientis. Bartonella DNA, showing 99% identity to Bartonella clarridgeiae, was detected in one pool (1.4%). No positive reaction was observed for any dog. This is the first detection of members of the ‘R. felis-like’ group other than R. felis in Chile.

No evidence of exposure to canine distemper virus (CDV) was detected in 70 samples corresponding to 58 wild-trapped Darwin's foxes (Lycalopex fulvipes) in Chile. Given its current endangered status and it being immunologically naïve, in the event of a CDV spillover from dogs to foxes, high population mortality is expected.