Training and intelligence
Chihuahuas are clever dogs, but it depends on the amount of effort the owner is prepared to put in. This breed can often suffer from small dog syndrome - people will tolerate bad bahaviour from them that would simply be intolerable and impractical in a bigger dog.
Chihuahuas have a confidence way beyond their tiny stature. They are cheeky and brave, and nothing and no one is too big a task or opponent for them. They may be best kept on lead as they have been known to run up to and provoke much larger dogs - and the Chihuahua unfortunately comes off owrse in any ensuing interaction.
Attitude towards strange dogs and people
Chihuahuas are not keen on strangers of any kind. Socialisation is a must to prevent them being over protective of their people, or antagonistic to other dogs. The Chihuahua does not think of itself as small and conducts itself accordingly.
Grooming and shedding
There are two coat types in the Chihuahua breed, smooth and long. The longer obviously needs more grooming than the smooth, but grooming of either is not excessive. They shed little.
The Chihuahua does need exercise, although they have bursts of energy. Some of their energy could be used in learning tricks, which this clever dog should be quick and agle enough to pick up well.
Need for company
They do like to be with their people, but Chihuahuas will tolerate being left for short amounts if brought up to it.
Like many toy breeds, Chihuahuas can suffer from a collapsing trachea, so it is better to have them on a harness than a lead. They tend to bond with one or two people. Because of their size they may be too fragile to live happily with young children. They like the company of other Chihuahuas.