The bush dog's proportions are unusual for a canid: a long body on short legs, a short tail, small ears and a broad muzzle. The feet carry partial webbing between the toes, and the animal is a confident swimmer and diver, moving through flooded forest and stream margins with ease.
Hunting is cooperative and exploits that water tolerance. Packs of about half a dozen pursue pacas, agoutis and capybaras, prey that habitually escape by entering water. Observers have described some pack members pressing the chase on land while others position themselves at the water, so an animal that dives is met on resurfacing.
The species is genuinely hard to study. Sightings are rare, density appears low across a very large range, and much of what is written about its behaviour comes from captivity or from a small number of field encounters. Its dentition is reduced, with fewer molars than typical canids, and molecular work places it as the sister lineage to the maned wolf, a pairing that no one would guess from appearance.