• Building dog pens allows multiple dogs to stay in one area at once.dogs image by lena Letuchaia from Fotolia.com
  
  Pens are smaller than fenced-off yards but big enough for dogs to move around and stretch out comfortably. Some pens take up large areas of a yard or rooms of a house, especially when you are creating a pen for many dogs. The size and dimensions of these pens all depends on what types of dogs you are keeping in the pen.
  
  

Fence Line

• Many outdoor dog pens can be simply built by stringing sections of fence together around an area. This is usually done in a backyard and with multiple dogs can be quite large. The type of fence you build depends on the size of the dogs. Wooden slats or metal chain link will keep dogs of all sizes within the fence. For big dogs which can stand at about four feet on their hind legs, the top of the pen's fence should reach at least as high as the dog's shoulder when they are standing on their hind legs so they can't jump out easily. The pen's fence should be secured in the ground or connected firmly together so that it can't be knocked over.
  
  

Different Areas

• The multiple-dog pen should have a couple different areas to allow the dogs maximum comfort. If built outside, the pen should have a shaded area to protect dogs from the sun, or a covered area to protect from the rain. It might even be a good idea to build a structure for this shade. If the multiple-dog pen is inside, old pieces of furniture that are usable for the dogs offer more variety than just a floor. In outdoor pens, healthy grass for the dogs is better than dirt, as it is more comfortable and keeps the dogs cleaner.
  
  

Separate Small Dogs from Big Dogs

• In larger pens, section off areas that only have openings in the bottom big enough for smaller-sized dogs. That way smaller dogs can separate themselves from larger dogs, yet also have access to the larger area to run around. This can be done with chainlink fence or wooden slats cordoning off the corner of one area of the pen. While small dogs often get along with big dogs, this is a good option in case the smaller dogs want to separated. It also allows these holes to be blocked off, so that the smaller and larger dogs can be separated permanently.