Between 18th October and 7th November 2010, three raccoon dogs were captured in Field Museum Tamakyuryo (FMT), and behaviour at fences was recorded by IP cameras at an enclosure. In this enclosure, fencing constructed of diamond-mesh wire netting, 150 cm in height, was used in conjunction with two types of mitigation commonly used in highway fences to prevent raccoon dogs from climbing (PVC board, Trical net). The raccoon dogs escaped successfully by both digging under (adult male) and climbing over the wire fence (yearling), but were not able to climb over the Trical net. Attempts to circumvent the mitigation treatments included biting, stretching the forelegs and/or stretching the nose upwards with standing on rear legs and pawing at the fence. Between October 2011 and October 2012, seven wild raccoon dogs were captured and measured at the TUAT campus, FMT, and Hinode town. These had a minimum paw width of 27 mm, indicating the largest fence mesh size capable of preventing them from climbing the fence. Their minimum lower jaw and canine width was, however, 12.4 mm, and therefore they were able to bite onto even this small Trical net mesh size of. Thus, maximum Trical net mesh size appears to be within 12.4 mm for purpose of bite-proof by raccoon dogs. The maximum gap between the forelegs was 53.6 cm, therefore PVC prevention board larger than this should not be scalable by raccoon dogs.