I’d stay away from the designer dogs… the “puggles”, “shiggles”, etc. for awhile. They are growing with rampant popularity and the puppy-mills are jumping on it. Lots of potential in-breeding and genetics problems. If you go this way, ask the breeder for names & numbers of owners. Talk to them about their dogs. If the breeder refuses, walk away.
Stay away from the “purse-rat” breeds. If it’s not bigger than a football, it’s not a dog for kids. They’re just not big enough to fend for themselves with kids, and are yappy/snappy and usually have personality issues.
With smaller kids around I’d go with a dog between 50 & 80 pounds. They’re big enough to take a few knocks, climb on, and run around with the kids.
Look for a dog in the “hound” or “working” classifications.
As mentioned labs or goldens are great dogs… not the sharpest tool in the shed, but are loyal, protective, and will play all day long. They love the water, and love to fetch. If you’ve got a pond/lake nearby watch out… they’ll be in it.
Border Collie - Extremely intelligent, and
very active. They can become destructive when they get bored… kinda like kids (It’s been claimed they have the equivalent intelligence of a 5 year old human). At age 3 or 4 they calm down a bit, but still have to run/exercise daily. Happy to be outdoors all day - bred for herding - and very protective.
Beagle - another intelligent dog… but as mentioned they have a set of pipes! You’d never imagine noise of that timbre coming out a dog that size. One beware… if they get wind of a rabbit/squirrel and go on the chase they will be fixated on this for hours and pursue (fenced yard a must).
Humane Society Mutt - Look for a good-sized dog, bright eyes, and wags it’s butt off around kids. (be warned - most of 'em will do this, but you’ll be able to tell which dogs are interested in kids) Ask the attendants if there’s info or a record on the dog… many loving families are forced to give up their dog due to a move or other family situation. Good thing here is they will be up to date on vacc’s, and in generally good health.
My current pooch is a Border Collie/Malamute mix.
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She loves the water, snow, and is great with kids. She finally stopped “herding” them into the corner of the yard

when a mob of them were over to play!