There was a rumour a dog would be grabbed in some way.
In terms of story structure, it would be the easiest way to convey what the Predalien is meant to be: A character has seen several of the 'usual' versions, then sees one from '
Alien 3', after hearing about both the canine incident and that the things apparently grow inside hosts and stuff. They say a line much like Ripley's, "So, what's laying these eggs?" But to do with realising they take on certain traits.
The scene either switches to the Predalien or the same character witnesses it together with the Predator and the percentage of the audience not already aware of how the genetic thing works, puts two and two together. It's simple and effective.
Personally, though, I'd rather see something far more vicious than the canine edition. One from a cat or, my most favourite idea, the aftermath of dozens of chestbursted animals from a local zoo, complete with a brief glimpse of the prior massed facehugger attack scene.
