Dogs can actually leap pretty high, when they are motivated.
The dogs wouldn’t have to jump over a fence, just high enough that they can use their front legs to hang with and their back legs to climb the fence.
It’s plausible.
My mother-in-law used to have a terrier-mix (pound puppy) that was a medium largish dog (60 lbs?) that could CLIMB a 4 foot chaiin link fence to visit his girlfriend next door. Despite being neutered :)