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 studies have reported lifespans that are shorter by between one and almost two years. Notably, dog breeds with flat faces and short noses have breathing difficulties, eye trouble and other health issues. The Fédération Cynologique Internationale recognizes over 300 dog breeds. A dog crossbreed is the result of mating two different breeds. A mongrel, mixed-breed dog or mutt is a dog that does not belong to one officially recognized breed and is not the result of intentional breeding. Natural breeds rose through time in response to a particular environment and in isolation from other populations of the species. This environment