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) of breeding stock (although the dogs must not vary too much in appearance from the breed standard, or they will not be registerable.). The emphasis is placed on hunting ability in the selection of breeding stock. In addition, inbreeding may be regulated. The Jack Russell Terrier Club of America code of ethics specifies that "a terrier will be rejected for registration if the inbreeding coefficient is more than 16 percent" in an effort to lessen hereditary disease in the breed. Independent working and hunting breed clubs sometimes maintain an open stud book. Dog breeds that are primarily kept as pets