If it's an ex dog, I'd be wary, especially with young kids. We went through this with our family, getting mature shepherds that were already trained but had been rejected for some reason (like a shepherd who was trained for police but wouldn't stop chasing cats). Each reject dog had serious issues. One would bite. One had separation anxiety. One was rough. My stepmum has extensive knowledge on dog breeding and dog training and every dog she brought home was returned. In the end, she bought a shep puppy - he was raised with four kids around (aged 4-12), he was trained to be an effective guard dog and he was part of the family.
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