Swamped

You could release some more animals. Nothing harmful, just enough to cause a ruckus. Then the Marshguards would be distracted enough that you might be able to focus on the pig's tracks.

It's not a great plan, but it's all you have. You can see a few slightly larger hogs; you passed over them when looking for one to trail, but they'll be better for making a distraction.

You let two of them out, only for Mantis to suddenly march in holding the original pig in one hand. With his free hand, he grabs one of the others and lifts it up, then glares at the third. It squeals a bit and starts moving back towards its pen.

"Would you care to explain what is going on here?" he says, turning his eyes towards you and walking towards the pens.

You can really understand what that pig was thinking right about now.