I swear I almost hit one of those coming home from a gig about a month ago. Looked like a cross between a deer and a dog. A crew guy in the vehicle behind me also commented on "WTF was that?" when we talked shortly afterwards. I'll have to send him the link.
We have a bunch of these "Chupacabra" sightings down here. They are almost always a coyote, or coyote-dog cross breed. Always with a bad case of mange.
I grew up right near the area in the news report. The Baltimore Washington Parkway actually serves like a basic wildlife refuge through the heart of urban PG county.