Owners with very intelligent or naturally smart dogs often have the most trouble with leaving their dogs at home alone. This is because these dogs are easily bored and need to have something to do both in a physical as well as a thinking way. As such, they often resort to what are called the boredom or destructive behaviors of chewing, digging, barking and generally getting into anything and everything possible.
One piece of advice that is often offered to owners of dogs that engage in these types of destructive behaviors when they are left alone is to provide more physical exercise. Of course the more exercise your dog has the more relaxed and content he or she will be to just hang out while you are away, but for highly intelligent dogs this is only part of the solution. Regular long walks, jogs and play times before being left alone are important, but so is stimulating their mental muscles as well.
Challenging your dog to use their mind means not following a predictable pattern all the time. Dogs, just like people, can get into routines and really don't have to think about what they are doing. Changing the order of the training routine, training in a different location or even walking the block in the opposite direction will give the dog something to think about and new things to explore. Even a few of these simple changes in a daily routine can really help a dog get the mental stimulation they crave so they can be relaxed and calm when you aren't around. This need for mental stimulation doesn't decrease with age, even if the physical activity level does decrease slightly for most dogs from being a puppy to being an adult. An intelligent dog can keep learning all their lives and will remain very curious and interested well into their senior years.
Housing a highly intelligent or smart dog with other companion pets can provide ongoing opportunity for socialization and interaction. It is important to match the breeds of dogs so the companion dog is just as interactive or else you aren't likely to be accomplishing your goals. Pairing a highly active and highly intelligent breed like a Border Collie or Australian Cattle Dog with a very sedate, although still smart breed such as a Bulldog is not a good combination for either dog. However, pairing a Border Collie with a smaller active terrier or even with a Lab or German Shepherd can be a terrific match both in physical activity levels as well as socialization and interaction requirements. Pairing two of the same breed is also a great option, however keep in mind that you still need to provide regular, ongoing training and challenges to keep both dogs engaged and avoid problem behaviors.
In some circumstances having more than one dog is not an option, but there are still ways to provide challenges to your dog to keep them engaged when you are away. There are several different types of chew toys that are designed to present problems for the dog to solve, keeping them focused on the toys rather than potentially problematic items in the house or room. An excellent option is a rubberized Kong toy that is open at one end. This opening has irregularly spaced rubber "fingers" that act to restrict food or treats from simply falling out. When you leave you simply push treats or small food kibble up into the toy, which is then held in by those rubber fingers. As the dog chews and plays with the toy, the fingers will bend and shift, allowing a treat or small piece of dry food to fall out every now and then in a random pattern. Dogs will play with these for hours, puzzling and problem solving over how to get to the treats. Since they are durable rubber and come in a variety of sizes, owners can select the Kong or toy that is just the right size to keep their dog busy and entertained.
Another option is to use a similar heavy duty rubber toy that is hollow and has at least one end open. Apply a fairly liberal smearing of peanut butter around the inside of the toy, which will attract and hold your dog's interest for hours. Since the peanut butter is sticky it will stay in the toy, creating a natural puzzle and challenge for your dog.
For those people with smaller dogs there are now battery operated balls and oddly shaped containers that roll about on the floor. These devices are durable and strong and typically have different rubberized chewing shapes and features. Like the first toys described, they also have a hollow compartment that can be filled with dry kibble or small dog treats. At pre-set times the toy food compartment opens and a small amount of the treats or food is released. The dog is continually rewarded throughout the day with random small amounts of food.
While all dogs are motivated by food, many dogs enjoy digging, finding hidden objects and even chewing on a good bone. Rather than just throw a bunch of toys out into the yard, consider hiding them or locating them under blankets, or in locations that the dog has to ferret out to actually get the toy. You will have to work with the dog for a few "searches" so that he or she understands what they have to do. They will quickly start to look forward to these games and searches and will enjoy playing with the toys that they find.
Other mental challenges for your dog can occur while you are home so they are more relaxed and calm when you away. Ongoing obedience or agility training is a great way to keep your dog mentally active, but so is playing games with them and talking to your dog. Even going with you in the vehicle when you run errands is a mental challenge as the dog has to follow commands in the vehicle, sees new places and new things, and gets to visually explore the world around them. Pairing a ride in the car with a walk in a new park or some time in training in an off-leash area can really complete the dog's requirement for both physical and mental exercise.