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
Breed club (dog) may be registered with breed clubs that have competition in dog shows and the breeding of showdogs and pets as their primary purposes. Most of the clubs have a closed stud book. Many dogs that are bred for show and pets are inbred, in order to make them as uniform in appearance as possible. Close inbreeding, called linebreeding, has only recently been recognised as problematic; generations of breeder manuals have recommended close inbreeding to produce a dog that is highly standardised in appearance. Today, testing for genetic defects before breeding is required by most breed clubs' code of ethics (but