As mentioned above, that the “ears will sit as meant to”, this means that genetics plays a huge role. Erect ears are part of the breed standard and therefore, a desirable trait.
includes the careful pairing of 2 dogs, striving to produce litters that will be as close to the breed standard as possible. If a pup’s parents (and grandparents…and up to 5 generations back) had excellent ear conformation, so should a pup.
With this all said, sometimes even a purebred AKC Chihuahua can have droopy ears….It can be a genetic quirk that simply happens once in a while and this does not mean that the dog is not a purebred. When this happens, it is considered a “fault” and the term for this is: broken down.
While the Chihuahua would not be able to be in conformation show events, this of course does not take away from him or her being the perfect pet. In regard to breeding, while drop-eared Chihuahuas are very cute, since this deviates from the standard and thus makes for dogs that are not genetically sound, they should not be bred as this trait can (and often is) passed down to the next generation.