The dog park can be a great thing for your dog(s). But it can also be very risky. Here are some tips on getting the most out of the dog park and minimizing the risks. 1 - Know your dog! If your dog is afraid of other dogs and/or people, the dog park is not the place to take him to "get over it". Hire a trainer to help you with his issues and evaluate when and if he's ready for the dog park. The same goes double for dogs that are aggressive with other dogs. It's unfair to the other park users to let your "bully" rule the park. Not to mention the risks you face should your dog hurt another dog or person.
Also, what type of play style does your dog have? Is he a wrestler, a chaser, or more of cocktail party mingler? Help your dog find dogs that have compatible styles. You might even try to schedule your visits when you know those dogs will be there... and avoid going when incompatible dogs frequent the park.
2 - Pay attention to your dog! The dog park is primarily so your dog can socialize, not so you can. It's fine to be polite and chat with other owners, but your dog should always be your first priority. You should know where he is and what he is doing at all times... and be ready to intervene or help him out should the situation warrant it. Do not chat on your phone, read your e-mail, or check your text messages in the dog park. You will lose focus and forget to watch your dog.
3 - Do not bring small children into the dog park. I see so many people make this mistake. The dog park is for dogs. Dogs run and jump and play rough at times. Small children are likely to get knocked over by playing dogs. There are also lots of dogs that are pretty nervous about young kids and that could lead to nipping or other fearful behavior.
If you have older kids, they can enter the park, but you must now watch the kids and the dog. The kids have to understand how to act around dogs so as to not threaten or harass them. They also need to be prepared to avoid running dogs and rough play. They can't assume that all the dogs are friendly and there for the kids to play with. The dog park is for dogs, not for kids so the needs of the dogs take priority. If in doubt, have the kids sit outside the fence and watch.
4 - Pick up after your dog! This seems like a no-brainer to me, but every day people don't even see their dogs pooping because they aren't paying attention to their dogs. Or they just act irresponsibly and don't bother. Aside from the obvious grossness of stepping in poop, many dog diseases are transmitted in feces so picking up poop helps keep the park clean and disease free. It also makes it more pleasant for the dogs and their humans. Most dog parks have baggies and trash cans available, so there is no excuse not to clean up. By the way, the excitement and exercise of the park may lead your dog to poop again even if he went at home before you came to the park. So always be prepared.
5 - Learn about dog body language. This can help you prevent a fight and ease the stress and tension that may happen. Recently I saw a fellow entering the park with his dog. There was a large dog standing at the gate and this fellow's dog started sniffing the ground and avoiding coming to the gate. What the guy didn't realize is that his dog was feeling anxious about the big dog "guarding" the gate and was doing her best to avoid or calm the situation. Had he persisted in pushing his dog to proceed, it's possible a fight may have resulted. This guy was "saved" by a silly, young dog that enetered behind him and distracted the big dog away from the gate.
I highly recommend that every dog owner read On Talking Terms With Dogs: Calming Signals by Turid Rugaas to better understand how dogs communicate. Then you will be better able to actually listen to what your dog is saying.
6 - Use good judgment about how often you visit the dog park and how long you stay. Many dogs just can't handle an hour a day at the dog park. It can be overly stressful and/or overly stimulating. So when you get home does your dog seem relaxed and happy or physically and mentally exhausted? Can you tell the difference? If he is relaxed and happy you're on the right track. But if he's exhausted, chances are you are going too often and/or staying too long. Adjust your schedule to find the right balance.
7 - Reward calm and polite behavior. Your trip to the park starts before you even get in the car. If your dog is "over the top" on the way to the park, then you are rewarding that out of control behavior by proceeding to the park. Ideally you want a dog that is calm, relaxed, and under control for the whole trip to, in, and from the park. He can be animated and happy - that's a good thing - but not out of control. He should respond to your voice cues and come when you call him. If he isn't at that level yet, contact a positive trainer to help you reach your goals.
When in the park be sure to praise your dog for wise choices and polite behavior with the other dogs. He needs to know when he's doing a good job. Be very careful about using food in the park as it might trigger some competition and aggression.
8 - Safety first! Remove any collar that could get caught during play before entering the park. Even flat collars can get snagged on a tooth and choke a dog, but be sure to remove any type of slip, chain, or prong collars (not that I advise using them in the first place!) as these could be serious dangers to your dog. I would carry your leash and collar with you in the park, just in case you need to calmly remove your dog. Leaving them at the gate leaves you empty handed, literally.
9 - One last thing... Have your dog on leash and under control while approaching and leaving the park. At a local dog park I was amazed to see people pull into the parking lot and just open the door and let their dog(s) out. There are so many things that could go wrong in that situation. Fortunately, nothing did, but the longer they practice that behavior, the greater the chances are that something will go wrong... dog running in street, knocking over the toddler at the next car, getting into a fight with an on-leash dog, etc. So play it safe and smart and make sure you have your dog under control at all times.
Then have FUN! I get the biggest kick out of watching dogs be dogs. They get along amazingly well despite all their differences and getting a regular chance to practice their social skills reduces the risks of aggression and is a good outlet for them.