Chihuahua how to see pure or impure

How can I tell if a Chihuahua is pure or not? The Chihuahua’s head should preferably be round with an “apple” shaped head, a slightly curved neck, a horizontal backline, a moderately long tail, narrow shoulders on the front limbs that taper downward, straight front legs so that the elbows are not constrained, strong muscles on the back limbs, and proper distance; the Chihuahua’s short-haired coat is very soft, tight and smooth. The Chihuahua’s head should preferably be round with an “apple” shaped head. Beautiful expression. Eyes are large but not prominent, well-proportioned and preferably bright black or red (yellowish or white dogs are allowed to have white eyes). The ears are large, erect and remain more upright when alert, but at rest, they are parted at an angle of 45 degrees between the ears. The muzzle is short and slightly pointed. The black, orchid and chocolate colored breeds all have nose colors that match their body color. Pale yellow breeds are allowed to have pink noses. Shear bite or pincer bite. Protruding upper jaw or protruding lower jaw is a serious defect. Ear clipping will result in disqualification. Chihuahuas have a slightly arched neck in the torso that is perfectly integrated with the shoulders. The backline is horizontal. Rounded ribs support the chest and make the body firm and strong (but not forming a barrel chest). The tail is of moderate length, held high or outward in a sickle shape, or curled on the back with the tip just touching the back (never caught between the legs). Short or broken tails are out of order. Chihuahuas have narrow shoulders on the front limbs that taper downward and straight front legs so that the elbows move without restraint. Shoulders should be up, balanced and firm, sloping toward the back (shoulders should not be down or too low). Wide chest and strong forequarters, but never like a “bulldog’s” chest. Slender feet, with toes well separated on the small, beautiful feet, but not too far apart, with thick pads (not like rabbit or cat feet). The ankle is slender. The hind limbs are strong and muscular, at the right distance, not too far in or too far out, looking down, strong and sturdy. The feet are the same as the forelimbs. The Chihuahua Shorthair has a very soft, dense and smooth coat (undercoat is allowed when the coat is large enough). The coat covers the dog’s body and has a collar tail, and the coat is sparse on the head and ears. The hair on the tail is similar to fur. Long hair type coat is soft, flat or slightly curved, preferably with undercoat. Ears with trimmed edges (if ears are thin and trimmed with more hair, ears may be slightly down and forward, but never down). The tail is full and long (feathered). Ideally: trimmed hair on the feet and legs, shorts in the rear, and collar on the neck. Long-haired type disqualified: sparse coat, nearly naked. Chihuahua weight should ideally not exceed 6 lbs. The proportions of the body are rectangular; so the length from shoulder to hip is slightly greater than the shoulder height. A slightly shorter body is ideal for males. Weights over 6 pounds are both out of order. The Chihuahua moves quickly and firmly and has a strong hindquarters drive. When viewed from behind, the hind legs are always parallel to each other and the hind feet always land close to the front feet. The front and hind legs both tend to lean slightly toward the center line of gravity, allowing for speed. Seen from the side, the front torso is oriented to match the hind torso drive, with the head held high. In action, the back line remains horizontal and stable. It is elegant and effortless, with a stretched and strong forelimb and a strong hindquarters drive. When viewed from the side, the stride length is appropriate, and when viewed from the front and rear, the walk is straight, which is due to the sound bones and muscles.