Wild “Pets” and Zoonoses

Illegal wildlife trade constitutes a major conservation problem for many species. For example, every year an estimated 100 tigers, 30,000 elephants and more than 1,000 rhinoceroses are illegally killed, and more than 1.5 million live birds are illegally trapped to be kept as pets. This represents the most visible side of this activity, the international trade, while on a local scale it remains largely unnoticed. However, local trade is widespread in certain areas of the planet, such as the Neotropics, with a long tradition of keeping wild-caught pets dating back to pre-Columbian times (Capriles et al. 2021).

Besides a conservation problem, this activity also entails a high risk for transmission of zoonotic diseases. Zoonoses, i.e. infectious diseases transmitted from animals to humans, constitute a major risk for human, livestock and wildlife health (Narrod et al. 2012). In recent years, we have witnessed zoonotic outbreaks with devastating consequences such as Evola, SARS or MERS. Most studies on this topic have highlighted the risk of wildlife markets for cross-species disease transmission (Woo et al. 2006). However, in many parts of the world people frequently keep poached wild animals as pets, which could also constitute a health risk (Green et al. 2020).

Figure 1. Young individual of Geoffroy’s Woolly Monkey (Lagothrix cana) kept as pet in the city of Atalaya, Peru © Pedro Romero-Vidal.

Yet the truth is that we still know very little about the magnitude of this problem on a local scale. To try to get a better picture, we conducted a continental-scale survey of rural human settlements over 13 years in 15 Neotropical countries, where the keeping of wild animals as pets is strongly rooted. On these surveys, we documented the vast extent of poaching to meet the local demand for pets, resulting in thousands of families living with ca. 275 species of wild animals (more than 10,000 individuals detected only in our surveys) without any sanitary controls. Parrots, for example, accounted for ca. 80% of wild pets and people live very closely with them, keeping them in their homes. This, which could be an amusing anecdote, is worrying when one considers that most of these animals die of disease at an average age of one year and are almost immediately replaced by other animals that follow the same fate. But disease transmission also has a reverse direction, as a significant number of wild animals kept as pets escape into the wild (almost a third of the individuals that people consider to be lost were due to escapes). These individuals, who have lived closely with poultry, may in turn have contracted diseases that they will now transmit to wild populations, some of which have significant conservation problems.

Figure 2. Dusky-headed Parakeets (Aratinga weddellii) and Yellow-crowned Amazon (Amazona ochroceaphala; perched on the back) kept as pet in an isolated house close to Puerto Bermudez, Peru © Pedro Romero-Vidal.

We cannot predict where an outbreak of a new disease will occur. But we do know that there are regions of the planet that are hotspots of biodiversity and, therefore, would be expected to be hotspots also for pathogens (Mittelbach et al., 2007). Such areas overlap with the tropics, and also with places where human population is experiencing high population and infrastructure growth, increasing connectivity between remote areas and large cities. Combined with the high demand for wild pets without any sanitary control, this entails a high risk for human and domestic animal health and for the native fauna itself.

Figure 3. Scarlet Macaw (Ara macao) kept as pet in a community at Manu National Park, Peru © Pedro Romero-Vidal.

In short, the practice of keeping wild animals as pets, which is widespread and culturally rooted in the Neotropics but also in other highly populated and rural areas such as some Asian countries, represents a major risk for human health and biodiversity conservation. Halting this illegal activity and strengthening health surveillance of animals and people in close contact with poached pets would benefit both people and wildlife.