Signs of aggression
Watch for the signs of aggression. Some signs may be subtle but if you aren't paying attention, and miss the initial signs, your puppy's aggressive behavior will get worse. For example: you have a guest over and your puppy jumps up on the guest in greeting. You command your puppy to sit and he instead leaves the room. You may rationalize that although your puppy ignored your command his disobedience wasn't really important because the same end was achieved – he stopped jumping up on your guest. But in your puppy's mind he has just won a battle and he may push the boundaries a bit further the next time. Never give your puppy a command unless you are prepared to enforce it.

If your puppy becomes possessive with his toys and growls if anyone goes near them he is showing aggressive behavior. Or maybe your puppy has a spot on the couch that he's claimed as his own and he growls if anyone else sits there. That is another example of aggressive behavior. Testing the boundaries he has been given as a puppy is normal in adolescence but it's important that your puppy's behavior is corrected in a consistent manner.

Should I confine my puppy if I leave him alone?
Confining a puppy when you're out, whether in a crate or a gated area, is not just about preventing housebreaking mistakes, it's also about preventing other bad habits from developing. Puppies, with their inquisitive minds and active jaws, can find all sorts of things to get into long after being reliably housebroken. For example, once a pup experiences the canine joy of shredding a Sunday newspaper, or tearing open a pillow from the couch, you will have a new and annoying problem to manage. It's far better if your pup never discovers such things.

Most pups should stay safely confined until they are a year old. If, for the last month or so, your pup has exhibited exemplary behavior when you are home, and no stress when left alone, then it may be time for a slow introduction to more freedom. Your job? Setting your pup up to succeed.

First steps
Giving your puppy brief bouts of freedom, interspersed with regular confinement, is a good way to start. This should not be a cold turkey situation where, all of a sudden, your pup goes from the usual confines of his crate to total freedom all day long. That kind of rapid and extreme shift in schedule can stress any pup, and stress leads to problems.

Instead, start by leaving him out while you make a quick run to the ATM or video store. Take him on a nice long walk before, do a little training, give him a special chew toy then go. Start slow, build on success.

Set your puppy up for success by puppy-proofing your home. Make sure that anything that can harm your puppy (cords he can get tangled in, objects small enough for him to ingest, etc.) are put out of reach. It's also a good idea to move any breakable objects so they will be out of a playful pup's way.

Start out by leaving your puppy in one puppy-proofed room, and close the doors to other rooms. Give your puppy a little freedom at a time. When that's gone well for a few weeks, grant access to another area. Remember: pups will often pick the least used area of the house if they are going to make a housebreaking mistake. Under the dining room table or in the guest room are frequent choices.

Leaving and greeting your puppy
When you leave, avoid heightened emotions. If you make a big deal out of leaving your puppy alone he'll react as though it is a big deal. The same goes for when you return. Huge emotional celebrations when you walk in the door condition your pup to expect a lot of excitement, and that sets him up to stress as he awaits your return. As with so many things, act the way you want your puppy to act. If you want him to be calm and matter-of-fact about your comings and goings then be calm and matter-of-fact about them yourself.

Two dogs are not much more trouble than one – and there’s no difference between walking with one dog or with two. What is important is that every dog must be trained separately.

The ideal partners are a male dog and a female dog. If you don't want offspring, one of the two dogs should be sterilized. Two males who grew up together can usually be good friends. It’s best to choose two puppies from one litter.

If a dog has already been living a long time in one home, he won't be enthusiastic about a new dog. The best place for them to become acquainted is on neutral ground such as the park.

Then, once the second dog is installed in the home, the first dog needs to get the usual attention and care from his owners. But, in order to prevent fights between him and the newcomer, both dogs must clearly understand that the owner is the “boss.”

If a cat and dog grow up together, though, they’ll learn each other’s language and become playmates.

If a cat comes into a home with a dog, things should go relatively well. The two pets should be kept apart for a few days, but should be able to hear each other from behind closed doors. Then they can make their first acquaintance with each other: Hold the cat in your arms and show her that the dog is a quiet, friendly animal. The dog, used to a pack, will accept the cat as a new member of the family – his pack. The cat will take longer to get used to the dog.

Nesting: A hole in the ground may provide a comfortable nest for your puppy. On a hot day the cold soil may also provide relief from the heat. Help your puppy keep cool by providing fresh water for him to drink, a shady area for him to retreat to, and maybe even a small plastic wading pool for him to cool off in.

Escape: Is your puppy digging because he has discovered that it provides an escape from the yard? Ensure that your fence is in good shape so as not to make the escape easier. If your neighbors welcome your puppy with treats ask them to stop. The treats may be encouraging your puppy to visit them, perhaps by digging an escape route under your fence! Supervision is the best prevention.

Fright: Is your puppy digging because he is frightened at being alone? Let your puppy know that you are not abandoning him when he is left alone for a short time. Leave your puppy for a few minutes, and then return with a treat for him. Do this again, letting the interval you are out of sight last a little longer. After doing this a few times, your puppy will understand that just because you are out of sight doesn't mean you have abandoned him. Of course, your puppy should never be left unsupervised for long periods.