It has many names in the local languages where it is endemic, such as: cachorro-do-mato-de-orelha-curta in Portuguese, zorro de oreja corta in Spanish, nomensarixi in the Chiquitano language, and uálaca in Yucuna. Other names in Spanish are zorro ojizarco, zorro sabanero, zorro negro.
After the formation of the Isthmus of Panama in the latter part the Tertiary (about 2.5 million years ago in the Pliocene), canids migrated from North America to the southern continent as part of the Great American Interchange. The short-eared dog's ancestors adapted to life in tropical rainforests, developing the requisite morphological and anatomical features. Apart from its superficial resemblance to the bush dog, the short-eared dog seems not to be closely related to any fox-like or wolf-like canid. It is one of the most unusual canids.
Two subspecies of this canid are recognized:A. m. microtis
A. m. sclateri
The short-eared dog can be found in the Amazon rainforest region of South America (in Peru, Bolivia, Brazil, Colombia, Ecuador and possibly Venezuela). There is a single report of "three slender, doglike animals" of this species sighted in the Darien region of Panama in 1984 by German biologist Sigi Weisel and a native Embera nation Panamanian; this rare species' presence in Panama is possible because of "the continuous mass of forest habitat that covers this region". It lives in various parts of the rainforest environment, preferring areas with little human disturbance. It lives in both lowland forests known as Selva Amazónica and terra firme forest, as well as in swamp forest, stands of bamboo, and cloud forest.
The short-eared dog has short and slender limbs with short and rounded ears. The short-eared dog has a distinctive fox-like muzzle and bushy tail. It ranges from dark to reddish-grey, but can also be nearly navy blue, coffee brown, dark grey or chestnut-grey until to black, and the coat is short, with thick and bristly fur. Its paws are partly webbed, owing to its partly aquatic habitat.
It moves with feline lightness unparalleled among the other canids. It has a somewhat narrow chest, with dark color variation on thorax merging to brighter, more reddish tones on the abdominal side of the body.
This wild dog is mainly a carnivore, with fish, insects, and small mammals making up the majority of its diet. An investigation led in Cocha Cashu Biological Station in Peru into the proportions of different kinds of food in this animal's diet produced the following results: fish 28%, insects 17%, small mammals 13%, various fruits 10%, birds 10%, crabs 10%, frogs 4%, reptiles 3%.
This species has some unique behaviors not typical to other canids. Females of this species are about one-third larger than males. The excited male sprays a musk produced by the tail glands. It prefers a solitary lifestyle, in forest areas. It avoids humans in the natural environment. Agitated males will raise the hairs on their backs.
Lifespan and gestation period are unknown, although it is assumed that sexual maturity is reached at about one year of age.
Feral dogs pose a prominent threat to the population of short-eared dogs, as they facilitate the spread of diseases such as canine distemper and rabies to the wild population. Humans also contribute to the extermination of the short-eared dog by degradation of the species' natural habitat and the destruction of tropical rainforests.
The short-eared dog is currently considered near threatened by IUCN. No comprehensive ecological and genetic research has been carried out on the species.