This is the most common mutt dog and is the easiest to identify because even after many crosses, they maintain some fundamental traits, like the size, the predominant white color, the black head, the short hair, the way it, which is hardly never more than 10 kg and, sometimes, the size of the ears, which normally bend frontward. Fox-terriers, besides conserving certain morphological characteristics, also maintain the attitudes and intelligence of their forefathers. They are, therefore, good hunters of small animals (foxes, rabbits and naturally mice), they know when it is necessary to bark and know how to be good watchdogs and excellent companions.
Because fox-terriers are used to living inside houses since many generations ago, they are considered authentic. They feel comfortable being around people and will not waste any opportunity of demonstrating their appreciation towards their masters. They are normally robust, short or medium height, they are resistant to fatigue, and they are usually long-lived: they can get to be older than 15.