The American Kennel Club (AKC) recognizes more than 150 dog breeds. This means that there are so many different breeds in existence today that it would be impossible to create a list of the “perfect pairings.” Also, there are so many things to take into consideration such as temperament, activity level, body type, age and size that it’s best to first decide what kind of dogs you want and check out their profiles to see if they would be a good match. If you already have a dog in the home, you’re off to an even better start. You already know you dog’s habits and temperament pretty well, so matching him with a compatible breed should be fairly easy.
When pairing your dogs, there are several hard and fast rules to make things easier for you and your pets. Most veterinarians would agree that pairing dogs of the opposite sex is better than pairing dogs of the same sex. Males and females have much smoother relationships than females will with females and males with males. The adult male is typically more dominant and the female is more submissive.
There is no rule against pairing dogs of the same sex, of course. Opposite sex pairings are just much easier overall. If you do plan to adopt two dogs of the same sex, you might want to consider adopting a dominant breed and a submissive breed. You will encounter much more conflict with two dominant dogs, and sometimes this conflict can be severe if your dogs are not extremely well trained.
Puppies and older dogs almost always get along, whether they are both male, both female or male and female. If you bring a puppy into the home with an older dog, the only problem you will have is the puppy will pretty much pester your poor older dog all day, and possibly all night long. Puppies are full of energy and your older dog may prefer resting all day to playing with a pup for hours on end. If the two pets meet at these very opposite stages in life, and your pets are well trained, you may not have the same problems as you would when dogs are introduced around the same age [or]the problems may not be as bad.
Overall, with the proper training and heavy involvement on the part of the owner, most dogs can be paired without producing any fatalities. Now, pairing dogs based on how vocal they are, how active they are, how large they are, how much they shed, etc., is entirely up to the owner. It may not be a good idea to pair two long-hair dogs if shedding bothers you and if you don’t want to listen to yapping all day, you may not want pair a Beagle and a Yorkshire Terrier.