When wild animals escape: could the exotic pet trade be our down fall?

Exotic pet ownership in the UK has grown 60% since 2000, according to the wildlife charity Born Free. But escaped wild animals are also a growing concern for their potential to spread disease, and the impact an invasive species might have on nature. The Guardian visits BeastWatch, an organisation of volunteers that specialises in the safe retrieval of exotic pets, and Bristol Zoo to see how wild animals are kept in captivity and ask if new laws can address some of the issues