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 breed standard may be accepted into one or more of the major registries (kennel clubs) of dog breeds include the Fédération Cynologique Internationale (covering 84 countries), The Kennel Club (UK), the Canadian Kennel Club, the American Kennel Club, the United Kennel Clubs International, the Australian National Kennel Council the New Zealand Kennel Club, and other national registries. The registry places the breed into the appropriate category, called a group. Some Groups may be further subdivided by some registries. Pure breed dogs have more health problems than mongrel dogs, and require more veterinary visits, and tend to have lower longevity. Indeed,