Tony, I think this is a picture from one of the K9 training academies in the country. What they're doing here, I think, is letting a cat walk the line, and test each dog's control over their instinct to "run down the cat and shred it". If one dog leaves the line, that dog fails and therefore doesn't graduate. I guess the prospect of not graduating compels them to succeed. =)
Of course, that's just my opinion, I could be wrong.
-Cyc