Chihuahua (dog) The affected chihuahua will hold its leg flexed, and foot off the ground until the quadriceps muscle relaxes and lengthens, after which the animal feels no discomfort and continues with activity. Chihuahuas are also prone to some heart-related disorders, such as heart murmurs and pulmonic stenosis, a condition in which the blood outflow from the heart's right ventricle is obstructed at the pulmonic valve. Chihuahua (dog) The Chihuahua () is the smallest breed of dog and is named after the state of Chihuahua in Mexico. Chihuahuas come in a wide variety of colors, and two coat lengths. The Chihuahua's history
Dog breed of the same breed and have an interest in dog breeding can form national Kennel clubs. Kennel Clubs maintain breed standards, record pedigrees in a breed registry (or studbook), and issue the rules for conformation dog shows and trials and accreditation of judges. They often serve as registries, which are lists of adult purebred dogs and lists of litters of puppies born to purebred parents. A dog breed is represented by a sufficient number of individuals to stably transfer its specific characteristics over generations. Dogs of same breed have similar characteristics of appearance and behavior, primarily because they come from