MERLE INFORMATION

MERLE CHIHUAHUAS ???

WITH THE CURRENT FAD AND POPULARITY OF THIS COLOR PATTERN TO SOME I FEEL I MUST GIVE SOME INFORMATION AS TO THE POTENTIAL HEALTH PROBLEMS ASSOCIATED WITH THIS COLOR PATTERN.  MANY PEOPLE INTERESTED IN PURCHASING A MERLE, MAY BE UNWARE OF THE PROBLEMS THAT THEY MIGHT HAVE WITH THEIR NEW PET.  MORE AND MORE KNOWLEDGE IS COMING OUT ABOUT THIS PATTERN AND HOPEFULLY BREEDERS WILL RECONSIDER BREEDING THIS COLOR PATTERN.

MANY COUNTRIES HAVE BANNED THE MERLE PATTERN; SOME BANNED THE REGISTRATION, SOME IT IS A DISQUALIFICATION IN THE CHIHUAHUA STANDARD, ETC.
MERLES LIKE ANY FAD (PEOPLE WANTING SOMETHING DIFFERENT) APPEARED IN LATE 1991.  THERE IS NO MENTION OF THIS COLOR IN ANY CHIHUAHUA BREED BOOK, OR GENETICS BOOK THAT LIST CERTAIN COLOR PATTERNS THAT ARE IN THE CHIHUAHUA BREED.  EVEN AKC DOES NOT HAVE ANY RECORDS ON THIS COLOR PATTERN, EXCEPT FOR THOSE BRED AFTER 1991.  THIS COLOR PATTERN HAS ALSO APPEARED SIMULTANEOUSLY IN SEVERAL OTHER BREEDS AS WELL.  COULD THIS BE, BECAUSE A BREEDER CROSSED A DACHSHOUND, SHELTIE, OR AUSTRAILIAN SHEPHERD INTO THE LINE?  YES, THEY ARE DIFFERENT, BUT THEY CAN COME WITH HEALTH PROBLEMS AS WELL.
THEY CAN ALSO HAVE WHAT IS CALLED A HIDDEN OR CRYPTIC MERLE, WHERE THE MERLE PATTERN DOES NOT COVER A LARGE AREA OF THE DOG (SOMETIMES ONLY A FEW HAIRS WILL ACTUALLY BE MERLE PATTERNED).

THE MERLE GENE IS A DOMINANT TRAIT, WHICH MEANS ONE OF THE PARENTS MUST BE A MERLE FOR THE GENE TO SHOW UP IN A PUPPY.  THIS IS NOT THE TYPE OF GENE THAT REMAINS HIDDEN FOR MANY GENERATIONS LIKE A RECESSIVE GENE.  SINCE MERLES WERE NEVER HEARD OF UNTIL RECENTLY (APPROXIMATELY 1991) THIS COLOR PATTERN PROBABLY RESULTED FROM CROSSING BREEDS THAT CARRIED THIS COLOR PATTERN.  I FEEL IT WOULD BE SAFE TO SAY, IF YOU BUY A MERLE CHIHUAHUA, YOU ARE PROBABLY NOT GETTING A PUREBRED CHIHUAHUA.  YES, THEY MAY OR MAY NOT BE REGISTERED, BUT IN “MY OPINION” THIS DOES NOT MEAN THEY ARE PUREBRED.  THE AKC STANDARD FOR THE CHIHUAHUA IS UP TO 6 POUNDS, BUT THE MAJORITY OF MERLE CHIHUAHUAS ARE CONSISTENTLY LARGE, IN THE 6 TO 12 POUND RANGE.  IN “MY OPINION” THIS IS VERY UNLIKE A PUREBRED CHIHUAHUA AND IS PROBABLY A RESULT FROM A THROW-BACK TO THE MIXED BREED DOG THAT WAS INTRODUCED TO GET THE MERLE CHIHUAHUA.
MERLES HAVE A HIGHER OCCURRENCE OF HEALTH PROBLEMS.  YOU MAY WONDER HOW THIS IS SO, WHEN MERLE IS ONLY A COLOR PATTERN?  THE MERLE GENE ACTS ON A COLOR AND LIGHTENS (WHITENS) CERTAIN PARTS CREATING PATCHES.  THIS WHITENING IS WHAT CAUSES DEFECTS. OFTEN, WHEN A DOG’S COAT IS WHITENED THE PIGMENT INSIDE THE EAR AND ON THEIR EYE, ALSO WHITENS.  THE RESULT IS A DEAF OR BLIND (OR BOTH) DOG; THIS IS DUE TO THE NERVE ENDINGS DYING.   THE DEAFNESS AND BLINDNESS CAN BE MILD OR SEVERE.  THE DOUBLE MERLE GENOTYPE MAY ALSO BE ASSOCIATED WITH ABNORMALITIES OF SKELETAL, CARDIAC AND REPRODUCTIVE SYSTEMS.

IF ONE PARENT IS MERLE AND THE OTHER PARENT NOT THIS IS CALLED HETEROZYGOUS, SINGLE MERLE OR Mm.  IF BOTH PARENTS ARE MERLE THIS IS CALLED HOMOZYGOUS, DOUBLE MERLE OR MM.  IN PUPPIES THAT ARE SINGLE MERLE HAVE A 36.8% CHANCE OF DEVELOPING SOME SORT OF HEARING LOSS, EITHER SLIGHT OR TOTAL DEAFNESS (Willis).  MANY BREEDERS WILL ADMIT THERE ARE PROBLEMS BREEDING MERLE TO MERLE, BUT THERE IS PROBLEMS BREEDING MERLE TO NON MERLE ALSO!!!  YOU CAN STILL GET DEAF OR BLIND PUPPIES FROM THIS TYPE OF BREEDING!!!  IF THE BREEDER TOLD YOU THIS PUPPY MAY NOT BE HEALTHY, WOULD YOU TAKE THE CHANCE AT THE EXPENSE OF HEALTH PROBLEMS?  THE PUPPY MAY APPEAR TO BE HEALTHY, BUT MIGHT ACTUALLY HAVE IMPAIRED HEARING OR VISION.  AS THE PUPPY MATURES IT MAY BECOME TOTALLY DEAF OR BLIND.  FOR MORE INFORMATION ON THE STUDY BY DR. WILLIS, AND FOR HIS VIEWPOINT OF THE MERLE PATTERN IN CHIHUAHUAS, HIS WEBSITE IS http://www.pedigreedogs.co.uk/k9bytes/merle.htm