Disease ecology of wild and domestic carnivores in Bolivia

Disease spillover from domestic to wild carnivore populations is increasingly recognized as a conservation threat. Domestic dogs and cats in rainforest (Madidi) and tropical dry forest (Chaco) in Bolivia were sampled for a serosurvey of canine distemper, parvovirus, feline panleukopenia, and calicivirus. Data were collected on demographics, hunting behavior, and ownership of dogs in the Chaco to investigate hunting dog ecology and determine its potential impact on native carnivores. Ocelots (Leopardus pardalis ), Geoffroy's cats (Oncifelis geoffroyi), jaguarundis (Herpailurus yaguarondi), crab-eating foxes (Cerdocyon thous), and pampas foxes (Pseudalopex gymnocercus) were trapped at three different sites in the Chaco: Isoseno communities, buffer zone, and Kaa-Iya National Park. Animals were sampled for a health evaluation, including hematology, serum chemistry, toxicology, nutrition, parasites, and serology. Epidemiologic models were constructed using data from the above studies and the literature to describe the spread of domestic dog pathogens from the dogs to wild carnivores. Results indicate that seroprevalence of pathogens is high in dogs; over 90% of dogs from both regions had antibodies to canine distemper virus and parvovirus. In the Chaco, dog populations are large and have high mortality and fecundity rates. Over 85% of domestic dogs participate in hunting. The average hunt lasts 11 hours and involves 2.7 dogs. Ocelots (7/10) and pampas foxes (4/5) had antibodies to canine distemper, crab-eating foxes (2/3) and pampas foxes (4/5) had antibodies to parvovirus. Geoffroy's cats (4/8) and ocelots (10/10) had antibodies to calicivirus, but only Geoffroy's cats (3/8) had antibodies to panleukopenia. Vitamin E levels were low in pampas foxes; vitamin A levels were low in Geoffroy's cats. No evidence for toxicologic exposure was found. Epidemiologic models indicate that directly-transmitted pathogens such as canine distemper virus are not serious threats to jaguars and ocelots. Population densities of these carnivores are too low to allow an epidemic to spread. However, indirectly-transmitted pathogens such as canine parvovirus can persist in the environment for extended periods of time, and are less dependent on host density for transmission. Epidemics of these agents could have severe consequences.