Dog exercise pens serve the same purpose for puppies as playpens do for babies: they keep them safe and out of mischief so that you don't have to watch them every second. Dog exercise pens can be used indoors or out. The are also useful when traveling, and almost all of them are easy to collapse and take along.

There are two ways to allow a dog to exercise in an unfenced yard without constant supervision: a trolley line or an exercise pen. A long trolley line might give your pet more room, but the longer it is, the more likely you'll spend a lot of time untangling your dog. Also, the dog might chew through the line and be off. Pens keep the dog in a limited area, and are especially useful for more than one dog.

Dog exercise pens are generally made of wire panels which can be assemble in a variety of configurations and sizes. While a large dog is never going to have enough room to really exercise in a pen, be sure to get the biggest practicable enclosure for any size animal. Place the pen in a sheltered area, and be sure that food and water dishes aren't likely to be tipped over. Extremes of temperature and windy days might call for a cover.

Dog Exercise Pens for Travel

For dogs that travel frequently, such as show dogs, there are mesh-sided pens. While these are very lightweight and easy to set up and take down, they are not recommended for home use, since they are chewable. If you travel occasionally with your pet, a light wire frame is best, and if you travel seldom, go for a heavier wire, since even small dogs can get rambunctious.