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
Maltese dog have originated in the mid-1960s on the U.S. East Coast and spread in popular use. This breed has been referred to falsely as the "Bichon", a name that refers to the family ("small long-haired dog") and not the breed. The Kennel Club officially settled on the name "Maltese" for the breed in the 19th century. The Maltese is thought to have been descended from a Spitz-type dog found among the Swiss Lake Dwellers and was selectively bred to attain its small size. There is also some evidence that the breed originated in Asia and is related to the Tibetan Terrier;