Teeth and Jaw problems in the Chihuahua
This condition seems to frequently affect the poor Chihuahua. Even when two adult Chihuahuas with perfect mouths have been bred together, one or more of the resulting puppies may have an incorrect mouth.
The KUSA Standard for the Chihuahua (both the Long & Smooth coated variety) states that the jaw of the Chihuahua should be strong, with a perfect, regular & complete ‘scissor’ bite.
A ‘scissor’ bite (‘bite’ refers to the teeth set within the jaw when the teeth are closed together) is when the upper incisors (front teeth) closely overlap the lower incisors and are set square in the jaw (also known as a ‘perfect 6×6 scissor bite’ – this refers to the 6 upper incisors and the 6 lower incisors)
Unfortunately, not all Chihuahuas mature to have a ‘perfect scissor bite’. This is a particular problem if you intend to show or breed from your Chihuahua.
Jaw abnormalities that can occur are: ‘Undershot Jaw’ (Bite), ‘Overshot Jaw’ (Bite) & ‘Level Jaw’ (Bite).
In a Chihuahua with an ‘undershot’ jaw the lower incisors will be in front of the upper incisors. This is usually quite easy to spot, even without opening the dogs mouth because the lower lip will be prominent of the upper lip in most cases. However, it always best to check the dogs mouth properly.
Conversely, an ‘overshot’ jaw is when the upper incisors are prominently in front of the lower incisors.
In a ‘level jaw’ both the upper incisors and the lower incisors sit level (upper incisors lain directly on top of the lower incisors) in the mouth when it is closed.
Above is a diagram showing the different levels of ‘bite’ in a dog.
The last diagram (fig. 10) shows a ‘level bite’
Puppies born with an incorrect bite are highly unlikey to gain a correct bite as they mature and will probably have the abnormality all of their life. Although, this tends not to affect the quality of life of the dog – it will be unsuitable for showing or breeding and the puppy should be rehomed as a ‘pet only’
However, puppies born with a ‘correct bite’ will usually have a correct bite as an adult. Sometimes, around the age of 5 – 7 months a Chihuahuas bite may become slighty undershot, overshot or level. But providing the puppy had a correct bite when it was born it should correct itself over the following few months as it matures (although it’s not guaranteed to).