Breed standards are the official guidelines that describe the ideal characteristics, temperament, and appearance of a breed and ensures that the breed is fit for function with soundness essential.
Kennel Club, London 1994
The Standard of the Chihuahua (Long Coat) is the same as the Standard of the Chihuahua (Smooth Coat) with the exception of the following:
COAT - Long, soft texture (never coarse or harsh to touch) either flat or slightly wavy. Never tight and curly. Feathering on ears, feet and legs, pants on hind quarters, large ruff on neck desirable. Tail long and full as a plume.
Any departure from the foregoing points should be considered a fault and the seriousness with which the fault should be regarded should be in exact proportion to its degree and its effect upon the health and welfare of the dog.