Took our dog to the field a couple of months ago. Sam is a 40Kg lab and right now is way too young to be trusted to run loose, so I kept him on a leash (which was something of an impediment to my flying[

])
One of the guys sugggested that I use a gadget he has that screws into the grass and secure the leash to this. He assured me it was strong enough to hold the dog. So, Sam was duly secured well away from the planes with access to shade and water.
All was well until a kangaroo decided to detour through the area where the dog was secured. (We have a large population of Roos that inhabit out field, somewhat surprising as we share it with the gun club! The roos often seem to be showing their opinion of less than perfect landings).
Anyhow, if there is one thing that Sam really likes to do it is to chase roos and wallabies. I'm not sure he would know what to do if he caught one, but it's unlikely as they easily outpace him! Sam took of in hot pursuit of said roo, only to come to a juddering halt when he got to the end of the leash! Fortunately the securing whatsit held, though it was a somewhat different shape after being used as an arrester hook.
After this I decided that future vists to the field should be deferred until Sam gets a little older (he's approaching 3). Can't really see me with him in a bag like Skyhigh Bev's dog.
Terry