The victim of the constriction is a crab eating fox (Cerdocyon thous).
A scientific article on this "constricting event" has been published, accompanied by some of these photos:
Almiron, D., H. Hulsberg, N. Luna, & T. Waller. 2011. A failed swallowing attempt upon a crab-eating fox (Cerdocyon thous Hamilton-Smith, 1839) by the Argentine Boa constrictor (Boa constrictor occidentalis [Philippi , 1873 ]). Herpetology Notes 4:359-362.