I read it too & the other ones. Basically you have to watch the Merle when you breed. 2 Merles [including one that is 'hidden' visually - you can't see the spots] create eye, ear and other problems. You need to know if your dog is carrying the Merle gene.
I think most dog issues stem from 'fancy' style breeding with no real understanding in genetics. The genes and DNA that make a trait are very hard to define - lots of combinations which of course is how we [& nature] have created variations in the first place. In nature, when a mutation thrives it becomes a new species [ie bears] but we don't see the ones that don't thrive, naturally, and there are lots. If there are issues - stop breeding! - I was a bit surprised they kept breeding that pair when there was obviously a problem. Making it out to be the healthy Merle's problem instead of the breeder's is biased writing and can twist the story. ________________________________ From: Kavi <[email protected]> To: [email protected] Sent: Sat, November 6, 2010 2:24:27 AM Subject: Re: [Chihuahuas] Fw: merle / Read this article on Merle chi's Hi everyone please read this article on merles. I think they are the cutest... but after reading this, I no longer want one.. http://www.picassochis.com/merles.htm shanna --- On Fri, 11/5/10, Amie McCaig <[email protected]> wrote: >From: Amie McCaig <[email protected]> >Subject: [Chihuahuas] Fw: merle >To: [email protected] >Date: Friday, November 5, 2010, 11:09 PM > > > >please read the article regarding merles. they may answer questions you might >have. > > > >My breeder and personal friend, who has been showing and breeding chi's for >more >then 20 plus years, is very seriously thinking about not breeding and chow >chis's due to the merle impact on the bred. and how difficult it is to find >quality animals without merle somewhere in the pedigree. >In europe merles are band from the show ring and not recognized as a bred color. > > >unfortantualy many many many breeders disagree with that the merle gene has no >affect on the bred, so they continue to use them in their breeding program. >for >exactly some of the reasons posted. > > >i stress that this is my opinion on merles. and I am only sharing information, >for individual education. Everyone can form their own opinions based on facts. > > >all the best, >Amie > >--- On Mon, 11/17/08, [email protected] <[email protected]> wrote: > > >>From: [email protected] <[email protected]> >>Subject: merle >>To: [email protected] >>Date: Monday, November 17, 2008, 10:56 PM >> >> >>------------------------------ >> >>http://www.genmarkag.com/canine_faqs.php >Health Problems Associated with the Merle Allele >Both heterozygous merle (Mm) and homozygous double merle (MM) dogs may >exhibit auditory and ophthalmic abnormalities including mild to severe >deafness, increased intraocular pressure, ametropia, microphthalmia >and colobomas. The double merle genotype may also be associated with >abnormalities of skeletal, cardiac and reproductive systems. > >Health Concerns >Increased Intraocular pressure: excessive pressure created in the eye. > >Ametropia: vision impairment due to a refractive error such that >images fail to focus upon the retina. > >Microphthalmia: a smaller than normal eye due to a defect occurring >early in development. Affected dogs may have prominent third eyelids. >Other eye defects are common in animals with this condition, including >defects of the cornea, anterior chamber, lens and retina. > >Coloboma – a defect in ocular tissue; a cleft or missing portion of >components of the eye, most commonly affecting the iris. >-------------------------------- >http://www.kandeechihuahuas.com/merles/ftlowille.html > >-----------------------------------------The Chihuahua standard reads, "any >color--solid, marked, or splashed." This refers to color, not modifiers that >act on color. The merle gene is a modifier producing a pattern, not a >color--the >merle gene modifies, or acts on, any color it is paired with. Deafness and/or >blindness (partial or complete) has already been proved to be associated >with a single copy of the merle gene in Chihuahuas . Once this foreign gene >gets >into our light colors (fawns, creams, white-spotteds, etc.), it will not be >detectable to the eye and it can easily creep into any line through an >outcross. >Color pedigrees will not help since many puppies change color as they grow and >are not registered correctly. > > > > >Merles & Genetics >For those who are not familiar with the merle gene, one fact is indisputable: >In order for a dog to BE a merle, it MUST HAVE one merle parent, either sire >or >dam. This gene cannot remain 'hidden' for generations, like chocolate or >blue, >which are recessive colors, thus proving that it has only recently been >introduced into our breed. > >A merle dog (Mm genetically) contributes one of these genes when bred, either >M >(merle) or m (non-merle). If a puppy receives the M (merle) gene, it will be >merle. If it receives the m gene, it will not be merle. The M (merle) gene >acts >on whatever coat color the puppy has. > >The problem with allowing the (new) merle color in Chihuahuas , is that we >have >so many light-colored dogs. Breeding these light dogs to merle will result in >fawn, cream, red, sable, white, etc. merles, which are often NOT recognizable >as >merles as adults(though when bred to black tris, they will produce blue >merles, >thus identifying one parent as a hidden merle). When these hidden merles are >bred to other merles (accidentally or unknowingly), thus doubling up on the >merle (M) gene, the result (if the puppy inherits one M--merle--gene from each >parent) will be a puppy with two M genes--a homozygous merle. These puppies >will >be deaf and/or blind, and some will have other internal health problems as >well >as possibly being infertile. The fact that they are deaf and/or blind will not >be recognized until they are older (around weaning time), hence a decision >will >have to be made about what to do with them.... > >At this time, there are already normal (single M) merle Chihuahuas which have >been diagnosed by two independent veterinarians with deafness and eye problems >that will lead to blindness. Is this really for the betterment of the breed? > > >The Inheritance of Coat Color in Dogs, by Clarence Little, when listing colors >for Chihuahuas , does NOT list MERLE. > > >----------------------------- >"The Trouble with Merle" Interesting article > >http://www.asca.org/Education/Advanced/troublemerle.htm > > >____________________________________________________________ >Click for FHA loan, $0 lender fees, low rates & approvals nationwide > >
