Please read this entire report and comments before making your own decision on this very important issue concerning the welfare of our beloved breed. If you are thinking about purchasing a Chihuahua that is merle patterned here are few things you might like to know that you may not be told. There is no proof that another breed was not bred to the chihuahua to get this pattern. So if you are purchasing this chihuahua as a purebred, you may want to look at a 5-6 generation pedigree. It has been proven that all merle chihuahuas go back to the same dogs. If you look at the genetics of chihuahuas, they do not carry the merle gene. Merle also very rarely, if ever appears from a mutation. Merle is also a very dominant gene. A merle only comes from a merle, there is no such thing as a carriers. So since chihuahuas do not carry this gene normally, it is my belief another breed was bred to one to get this pattern. There are genetic conditions that come with the merle gene. If you do decide to purchase one, request to see the Parents along with your puppies CERF form along with their BAER form. CERF is a eye certification form that can only be done by a licensed ophthalmologist. BAER is a hearing test that can only be done by a certified audiologist. These tests are commonly done on the current breeds that have the merle pattern. Shelties, Australian Shepards, Australian Cattle Dogs..etc. They have databases on these breeds. Chihuahuas, however, do not have such a database since the merle pattern has only been around for a few years. Also remember that the puppy you purchase will have to be CERFed every year because something congenital can appear at any time. The price of a dog should be based on the quality of the dog at the time it is sold and not on a color or pattern. The Do Nots of Chihuahua Buying 1 ). Do not buy from a reproducer with no name registrations, APRI, CKC,( continental kennel club ),NKC, ACA, APA, ADBA, APR, WKC, NAPDR, IKC, UKC, (universal kennel club ) These are unregulated registries and there are basically no restrictions for registering dogs. They have no system of kennel inspections. If reproducers are using registries other than AKC there must be a reason , such as AKC's DNA requirements and record keeping. It is against AKC policy for breeders to charge more for AKC registration papers. If the reproducer is doing this, run ! 2 ). Do not buy from a reproducer claiming "show quality" puppies and they do not show. No ifs, ands, or buts. They have no idea what they are breeding. These reproducers cannot decipher show quality in a puppy under 4 months of age and not at all if they are not actively exhibiting. You can look up their dog by putting the AKC registered name in a search engine such as google. Show catalogs and results are available online. Ask them for proof they show. Real International Championships are only available through FCI. 3). Do Not buy from a reproducer online if they do not even have their name on their web site. How proud can they be of their dogs? What are they hiding? 4). Do Not buy from a reproducer using any of these terms to describe the dogs, teacup, rare color, miniature, designer lines, tiny tinies. Chihuahuas are one breed, there is no such thing as a toy or standard, or teacup. These are descriptive terms that are used by unknowledgeable reproducers. 5 ). Do not put down a deposit on a pup not born or a pup under 8 weeks old. Be wary of reproducers that allow Chihuahua pups to leave before 12 weeks of age. 6 ). Do not buy from a reproducer that only shows partial pedigrees if that is important to you, ask to see the whole pedigree. Otherwise know that they are promoting their pups off the work and showing done by legitimate breeder/exhibitors, something they have no knowledge of and yet they use it to sell dogs. A champion in the 3-4 generation is no guarantee of quality. 7). Do not buy the new "rare merle" Chihuahuas. This is not a color pattern that has been in Chihuahuas. It most likely appeared after some bred a Dachshund or a Sheltie to a Chihuahua. They can have a vast array of health related problems, including deafness, blindness, and PRA. Most will be over the size for the standard. ( 6 lbs) In the breeds where this color normally occurs, they have limited their acceptable colors to 3-4 only. Chihuahuas can have almost unlimited colors and only breed experts are knowledgeable enough to know the genetic problems that can be caused breeding to certain color patterns. At this time none of the merles we have seen have been tested for these genetic conditions. Testing is expensive and if the parents are not tested then the results of the offspring should be suspect. Be aware that some states have "puppy lemon laws" and these sellers could be heavily fined for selling pups with health defects. I have written to different geneticists for answers. I have received one reply so far. ---------------------------------------------------------------------------- ---- My Email I would like any information you may be able to provide me concerning the Merle Pattern Gene. I have been in Chihuahuas for 8 years and never saw a Merle. I have friend who has been in them for over 30 years and hasn't seen them either. They are now being produced. We have both been trying to prove that another breed had to introduced to produce this pattern. Are we correct in this? People are trying to say that it could be a mutation. I haven't found any information that backs that up. All I have found says that some colors can be mutations, but not patterns. Everything we have found says you must have a merle parent to get merle offspring. No dog carries the gene without being merle itself. Are we understanding that correctly? Any information you may be able to provide would be greatly appreciated. Thank you in advance ---------------------------------------------------------------------------- ---- I was asked by my colleagues at TAMU to respond to your query on merle genetics. At least nine genes are thought to be responsible for pigment and pigment patterns in dogs. The gene designated by the letter M has two alleles: the dominant M, which produces the merle pattern, and the recessive m, which results in the absence of the merle pattern. As far as we know, all dogs carry two copies of this gene. Those that are homozygous mm do not show the merle pattern (alternating light and dark areas, with the light sometimes being white). Those that are heterozygous (Mm) display the merle pattern. Those that are homozygous MM are usually solid (or nearly) white, often deaf, blind, and sterile, depending on breed. According to the source I rely on the most, CC Little's book The Inheritance of Coat Color in Dogs (1957, Howell Book House, NY), the Chihuahua breed only carries the recessive m allele. However, this same source says that Pomeranians do not carry the dominant allele either, but I just saw a photograph of one, so this is not necessarily an absolute reference source. We don't know the location or sequence for the merle gene in dogs so I cannot say what sequence differences account for the two alleles. It seems highly unlikely, however, that a NEW spontaneous mutation in the recessive allele in your breed would produce the same phenotype of the dominant allele. I could not say this as an absolute, but in my opinion the merle has to have been introduced from another breed. Because the merle pattern is dominant, it could not have lain "silent" for many generations, only to reappear fairly recently. This doesn't give you the black-and-white answer you would like, but perhaps it helps. In a second email asking permission to post Dr Strain replied: "You are welcome to post my comments. I hope it would be clear that I am not attacking anyone. I am willing to try to respond to individuals who contact me." George M. Strain Professor of Neuroscience Comparative Biomedical Sciences Louisiana State University School of Veterinary Medicine Baton Rouge, LA 70803 Voice 225-578-9758 Fax 225-578-9895 Research: www.lsu.edu/deafness/deaf.htm
