Can Severe Mange Explain “Chupacabra” Sightings?

You're on the right track. Animals reported as "chupacabras" in Texas and elsewhere have generally turned out to be coyotes, foxes or dogs with severe sarcoptic mange. Heavy infestations cause widespread hair loss, thick crusted and darkened skin, and weight loss, which can make a familiar animal look very strange.

Mange doesn't cause insanity, but it can change behavior. Sarcoptic mange is intensely itchy, and in severe cases animals become weak, thin and ill from secondary skin infections. A miserable, sore animal may avoid being touched, act more defensively, or scavenge closer to people because it's struggling to hunt. Studies of urban coyotes have found that mangy animals spend more time near people and are more active by day.

Sick wild animals are best left alone; call your local animal control or wildlife agency rather than approaching one. Coyotes and foxes can carry scabies mites to dogs, so keep pets away from them. Read more about sarcoptic mange in dogs, including how it spreads.

This is general information, not a diagnosis. Please follow your own vet's advice.