Disease: A Hitherto Unexplored Constraint on the Spread of Dogs (Canis lupus familiaris) in Pre-Columbian South America

Although debate continues, there is agreement that dogs (Canis lupus familiaris) were first domesticated in Eurasia, spreading from there to other parts of the world. However, while that expansion already extended as far as Europe, China, and North America by the early Holocene, dogs spread into (and south of) the tropics only much later. In South America, for example, the earliest well attested instances of their presence do not reach back much beyond 3000 cal. BC, and dogs were still absent from large parts of the continent – Amazonia, the Gran Chaco, and much of the Southern Cone – at European contact. Previous explanations for these patterns have focused on cultural choice, the unsuitability of dogs for hunting certain kinds of tropical forest prey, and otherwise unspecified environmental hazards, while acknowledging that Neotropical lowland forests witness high rates of canine mortality. Building on previous work in Sub-Saharan Africa (Mitchell 2015) and noting that the dog’s closest relatives, the grey wolf (C. lupus) and the coyote (C. latrans), were likewise absent from South and most of Central America in Pre- Columbian times, this paper explores instead the possibility that infectious disease constrained the spread of dogs into Neotropical environments. Four diseases are considered, all likely to be native and/or endemic to South America: canine distemper, canine trypanosomiasis, canine rangeliosis, and canine visceral leishmaniasis caused by infection with Leishmania amazonensis and L. colombiensis. The paper concludes by suggesting ways in which the hypothesis that disease constrained the expansion of dogs into South America can be developed further

Parasites of domestic and wild canids in the region of Serra do Cipó National Park, Brazil Parasitos de canídeos domésticos e silvestres na região do Parque Nacional da Serra do Cipó - Brasil

Over recent decades, diseases have been shown to be important causes of extinctions among wild species. Greater emphasis has been given to diseases transmitted by domestic animals, which have been increasing in numbers in natural areas, along with human populations. This study had the aim of investigating the presence of intestinal helminths in wild canids (maned wolf, Chrysocyon brachyurus, and crab-eating fox, Cerdocyon thous) in the Serra do Cipó National Park (43-44º W and 19-20º S) and endo and ectoparasites of domestic dogs in the Morro da Pedreira Environmental Protection Area (an area surrounding the National Park). The Serra do Cipó is located in the state of Minas Gerais, Brazil. Among the enteroparasites found in domestic and wild canids, the following taxons were identified: Ancylostomidae, Trichuridae, Toxocara sp., Spirocerca sp., Physaloptera sp., Strongyloides sp., Cestoda, Dipylidium caninum, Diphyllobothriidae, Hymenolepidae, Anoplocephalidae, Trematoda, Acanthocephala and Isospora sp. Domestic dogs were positive for leishmaniasis and Babesia canis in serological tests. Among the ectoparasites, Rhipicephalus sanguineus, Amblyomma cajennense and Ctenocephalides felis felis were observed in domestic dogs. Variations in the chaetotaxy of the meta-episternum and posterior tibia were observed in some specimens of C. felis felis.<br>Nas últimas décadas, as doenças têm sido apontadas como importantes causas de extinção de espécies silvestres. Maior ênfase tem sido dada às doenças transmitidas por animais domésticos que crescem em número, bem como as populações humanas, em áreas naturais. O presente estudo objetivou verificar a presença de helmintos intestinais de canídeos silvestres (lobo-guará - Chrysocyon brachyurus e cachorro-do-mato - Cerdocyon thous) do Parque Nacional da Serra do Cipó (43-44º W e 19-20º S) e endo e ectoparasitos de cães domésticos da Área de Proteção Ambiental Morro da Pedreira (entorno do Parque Nacional). A Serra do Cipó está localizada no Estado de Minas Gerais, Brasil. Entre os enteroparasitos encontrados em canídeos domésticos e silvestres, os táxons seguintes, Ancylostomidae, Trichuridae, Toxocara sp., Spirocerca sp., Physaloptera sp., Strongyloides sp., Cestoda, Dipylidium caninum, Diphyllobothriidae, Hymenolepidae, Anoplocephalidae, Trematoda, Acanthocephala e Isospora sp. foram identificados. Cães domésticos foram positivos para leishmaniose e Babesia canis nos testes sorológicos. Entre os ectoparasitos, Rhipicephalus sanguineus, Amblyomma cajennense, Ctenocephalides felis felis foram observados em cães domésticos. Variações na quetotaxia do metepisterno e tíbia posterior foram observados em alguns espécimes de C. felis felis