A dog run, just as the name implies, is an outdoor enclosure long enough to allow a dog to run.
The floor of the run. The surface or floor of a dog run should provide a solid, rough footing. Concrete is generally regarded as the best surface, and, if possible, should be used for at least a part of the run, particularly in the sunning and feeding area. When laid, it should be rough-troweled or brushed, not ‘steeled’ to a smooth, slippery finish.
Another answer is to build a simple 3 to 4-foot-square wooden platform on four 2 by 4 legs. Your dog can jump up on it to look around, and can rest beneath it in the shade.
Asphalt is a poor surface for a dog run, because it is absorbent and gets hot and often tacky on a warm day.
Gravel is good. It provides good drainage, changes temperature slowly, and provides the best possible footing for a dog. Because it is somewhat difficult to clean, gravel in a run should be removed and replaced about once a year. For a good gravel run, lay a foundation of about 8 inches of crushed rock, then cover with 2 ½ to 3 inches of pea gravel.
The fencing. The fencing can be of almost any material. Wire is usually least expensive, and it gives your dog a chance to see what is going on around him. Wood or other solid paneling gives good wind protection and some degree of shade. A com-bination of wire and solid fencing as used in the run shown here is excellent.
Height of the fencing depends more on the type of dog than his size; some small dogs are ‘jumpers,’ whereas larger but short-legged breeds such as the dachshund and Welsh corgi seldom jump. About 3 to 4 feet is a safe height for toy breeds. Collies require 5 feet, Airedales 7 feet, German shepherds 8 feet.
If you use welded wire for the fencing, 12 ½ -gauge galvanized is satisfactory (and inexpensive) for all breeds of dogs. Chain-link wire fencing costs slightly more. Quite a few twisted wire fencings are also suitable. For small dogs, a twisted wire fencing of 16 to 18 gauge with 1-inch mesh is satisfactory; for large dogs, 12-gauge with 3-inch mesh is good.
String the wire on either steel or wooden posts, placed not more than 8 feet apart. You can use steel T-posts for wire fencing, but round pipe posts are preferable at the gate. Particularly at the gate, set fence posts at least 2 feet deep in concrete.
Welded wire needs no reinforcing, but chain-link and most twisted wire fencings are limber. They should be strengthened with a horizontal pipe along the top or with taut reinforcing wires at top, bottom, and center. Otherwise a dog can jump on the wire and bend it enough to climb it.