1. Independent – Bitches tend to want to be in control of the entire situation. They may come to their owner when they are seeking affection but will often move away when they have had enough.
   
    
2. Stubborn – In many packs, a bitch is typically the Alpha. Female dogs crave more control of situations and are quick to respond to perceived challenges with fierceness.
   
    
3. Territorial – Female dogs mark in the same way male dogs do. A spayed female may continue to mark for her entire lifetime regardless of when she is spayed while most males will cease marking behaviors shortly after they are neutered and the testosterone levels subside.
   
    
4. Reserved – Bitches are generally less affectionate and friendly than male dogs. This characteristic is noticeable in puppies and becomes more pronounced with age.
   
    
5. Changes in Mood or Behavior – It is also important to note that if you do not spay your bitch, she will come into heat at approximately one year of age and approximately every six months thereafter. During this time, there will be some bleeding as well as a change in mood or behavior.
   
    

The following characteristics often apply to male dogs: 
 

1. Affectionate – Male dogs are typically more affectionate than bitches. They tend to crave attention from their owners more than bitches and as a result, display more affectionate behaviors.
   
    
2. Exuberant – A male dog is also more likely to be fun-loving and outgoing throughout his lifetime than a bitch. While a bitch tends to become more reserved as she ages, a male dog maintains a more puppy-like exuberance throughout his lifetime.
   
    
3. Food-Motivated – Males are often very motivated by food. This food motivation can make training extremely easy as treats can be used to lure and reward a dog to display desired behaviors. 
    
4. Attentive – While bitches tend to be more independent, males tend to be more focused on their human companions. They want to always be close to the human and are very eager to please.
   
    
5. Aggressive Behaviors – It is also important to note that intact males may display aggressive behaviors toward other males or exhibit marking behaviors. Additionally, intact males should be kept away from females in heat unless a breeding is planned.
    

Dog owners who are adding an additional dog to their home should carefully consider the ramifications of adding a dog of either sex. This is important because the makeup of the existing pack may be more accepting to either a male or a female dog. The following are general tips for selecting the gender of a second dog:
 

1. If you already have a male or a female, a dog of the opposite sex is generally the best choice. Dogs of the same sex are more likely to fight than dogs of the opposite sex.
   
    
2. If you already have a male dog, he is likely to be more accepting of a female and you are likely to have fewer dominance issues if you add a female to the pack. However, if you opt to add another male to the pack, they can peacefully co-exist and may even become friends. It is important to closely monitor their interactions early on to ensure aggressive behaviors do not become common.
   
    
3. If you already have a female dog, she is likely to be more accepting of a male. Most males tend to be submissive. If he does not challenge your resident female, she is not likely to have a reason to fight with him. Adding a female dog to the pack, however, may result in complications. The worst combination of dogs is two bitches because they are more likely to fight than a male and a female or two males. However, many dog owners have two or more bitches that live together without problems. As long as there is an established Alpha and the other bitches know their place in the pack, there will not be dominance struggles often, although they may still occur.
    

Selecting a male or female dog is largely a matter of personal preference. The above characteristics are generalizations, and it is certainly possible to acquire a female puppy who displays male characteristics or a male puppy who displays the typical female characteristics. Additionally, bitches that are spayed and dogs that are neutered often do not have the gender-specific problems associated with their sex such as coming into heat or marking.