Dog parks allow dogs to socialize and run free, and many pooch parents feel safe letting their canine companions take part. But not all dogs are created equal in these spaces.

For one thing, nervous dogs may be overwhelmed by the canine roughhousing. It stands to reason, because dogs don’t naturally gather in a strange place with strange dogs and simply fall in line.

Instead, dogs given free rein can easily become overstimulated and then aggressive. In turn, other dogs may withdraw and become frightened. Some can pick up bad habits. At worst, timid, often smaller, dogs can be hurt by more domineering ones. What’s more, you’re trusting strangers that their dogs won’t transmit infectious diseases.

Dog parks can still provide a healthy outlet for your pooch — if you and your pooch are prepared and you monitor what’s going on.