tug free

[Bushwhacker]

Someone grips a couple of dogs, and those ones tug free to escape.

Please, what is the meaning of "tug free"? They struggle to get free from the grip?

Thank You

[euncu]

***neither a teacher nor a native-speaker***

What I tell from your sentence;

The dogs unleash themselves by using their strength (probably, using the strength of the neck muscles by abruptly and forcefully moving their heads to the opposite direction of the end of the leash or using the strength of the leg muscles by rushing the opposite direction of the end of the leash).This way the one holds the leash has to let go of the dogs.(the end of the leash slips from the holder's hand)

[Anglika]

Doesn't have to involve a leash.

The dog that is being held gives a sudden hard jerk and pulls itself free.