Just snare the larger beaver off and leave the smaller ones for next year. Food and fur on the long term plan. To prepare snares, boil them in water and place outside to weather. The snares don t really rust, but will become dull after 45 to 60 days. Remember snares are hard to find so make darn sure you are keeping track of them.
Some trappers use surveyor tape to mark the snare locations, some use sticks against nearby trees.
Whatever you do, make sure you know where and how many you set. This is especially important in a survival situation where you can t buy more snares. Dogs once again will come up. Generally, dogs will not be harmed when caught in snares. Dogs once caught in a snare, stop fighting the snare and think their master just stake them out there instead of at home.