Mexico has a long history of parasitological studies in communities of vertebrates. However, the mega diversity of the country makes fauna inventories an ongoing priority. Presently, there is little published on the parasite fauna of gray foxes (Urocyon cinereoargenteus Schereber, 1775) and this study provides new records of parasites for gray foxes in central Mexico. It is a continuation of a series of previous parasitological studies conducted with this carnivore in Mexico from 2003 to the present. A total of 24 foxes in the Parque Nacional El Cimatario (PANEC) were trapped, anaesthetized, and parasites recovered. The species found were Dirofilaria immitis, Ctenocephalides canis, C. felis, Euhoplopsillus glacialis affinis (first report for gray foxes in Mexico) Pulex simulants, and Ixodes sp. Three additional gray fox carcasses were necropsied and the parasites collected were adult nematodes Physaloptera praeputialis and Toxocara canis. The intensive study of the gray fox population selected for the 2013-2015 recent period allowed for a two-fold increase in the number of parasite species recorded for this carnivore since 2003 (nine to 18 parasite species), mainly recording parasitic arthropods, Dirofilaria immitis filariae and adult nematodes. The parasite species recorded are generalists that can survive in anthropic environments; which is characteristic of the present ecological scenario in central Mexico. The close proximity of the PANEC to the city of Santiago de Queretaro suggests possible parasite transmission between the foxes and domestic and feral dogs. Furthermore, packs of feral dogs in the PANEC might have altered habitat use by foxes, with possible impacts on transmission.

Mexico is a highly diverse country where ticks and tick-borne diseases (TBD) directly impact the health of humans and domestic and wild animals. Ticks of the genera Rhipicephalus spp., Amblyomma spp., and Ixodes spp. represent the most important species in terms of host parasitism and geographical distribution in the country, although information on other genera is either limited or null. In addition, information regarding the influence of global warming on the increase in tick populations is scarce or nonexistent, despite climate conditions being the most important factors that determine tick distribution. In order to aid in the management of ticks and the risks of TBD in humans and domestic animals in Mexico, an analysis was conducted of the gaps in information on ticks with the purpose of updating the available knowledge of these ectoparasites and adapting the existing diagnostic tools for potential distribution analysis of TBD in wildlife. These tools will help to determine the epidemiological role of wildlife in the human–domestic animal interface in anthropized environments in Mexico.

ResumenEl estudio de la parasitofauna de carnívoros silvestres es indispensable por su potencial uso como especies centinelas de la salud de los ecosistemas. Este estudio se llevó a cabo en la zona conurbada de Santiago de Querétaro, México, en donde se registró la presencia de filarias del nemátodo Dirofilaria immitis por medio de frotis sanguíneos en una zorra gris macho Urocyon cinereoargenteus, capturado en noviembre de 2013. Análisis posteriores señalaron la ausencia de nemátodos adultos en el corazón del cánido, pese al registro de las filarias en sangre. Se cuenta con registros previos de D. immitis en coyotes en Querétaro, pero se desconocía su presencia en este cánido silvestre.AbstractThe study of the parasite fauna of Mexican wild canids is relevant because of their potential as sentinel species for ecosystem health. The following study was conducted in a suburban area in Santiago de Querétaro, Mexico. We registered Dirofilaria immitis filariae in a gray fox male Urocyon cinereoargenteus blood sample on November of 2013. Further analysis showed there were not adult heartworms infecting the gray fox indicating that the animal was in the initial stages of infection. There are previous records of D. immitis in coyotes and stray dogs in Querétaro, but this nematode has yet to be registered in this host species