07/12/2023
Food for thought… Copied from a breeding page.
Here is some scientific useful information for the new breeders of “Merle patterned hybrid breeds”. If you’ve been breeding the Merle pattern into your breed, you already know this.
THIS DOES NOT APPLY TO DOGS GENETICALLY DISPOSED WITH THE MERLE PATTERN.
Merle is dangerous 100% of the time with a breed that already has genetic issues, as the Boston terrier, chihuahuas, English (British) bulldog, bully, microbully, and French bulldog do. So adding an already looming genetic flaw (deafness & blindness) with a line that has pre-existing health issues, what do you think happens? Merle patterned bostons and Frenchies will never be recognized as “standard” by a reputable registry as you cannot have the Merle pattern without adding a secondary breed.
I am a genetic research analyst. These are facts!
DAY 1: Brief Merle Pattern Introduction:
In simple terms the Merle pattern has a host of health problems. The debate is not about the charm and beauty of Merles as I think we all agree it is quite striking. To reiterate it is indeed a unique pattern and eye catching (this data is not about the dislike of Merles). Unfortunately for Merles, being beautiful and healthy are two different things. There are severe optical and hearing issues caused by this mutated gene, at birth and later in life for many Merle offspring. Another cause for concern is the possibility of a defective immune system and the hidden (ghost) merle. This lethal gene causes many puppies to be stillborn, have missing eye lids, and a host of other health issues. I cannot stress enough how dangerous this mutated gene is to a dogs overall health and quality of life. There is no ethical purpose in breeding this pattern into a dog just for a 'unique look'. Every time a Merle pattern is bred into a dog, the breeder is gambling between healthy and unhealthy. Meaning, how many in this litter will be healthy and how many in this litter will be unhealthy at some point in its life. There are lethal health risks with the Merle pattern in any dog breed therefore it should not be added to breeds where the pattern does not already exist! This is NOT the same as "I am just creating a new dog breed like many have done in the past" which is the premise of all breeders taking this risk. This mutated gene is faulty and lethal. Which makes it very difficult to manage safely. This is why Merle is banned in many countries.
*Sorry to use this tragic Merle Chihuahua but this is the Merle reality.
This picture represents the mutated gene at its worst. Sometimes in order to get peoples full attention, they need to see with their own eyes the worst of a reality.
Day 2; WHAT IS MERLE?
It is a PATTERN in a dog's coat, though is commonly INCORRECTLY referred to as a color. Merle is a pattern. The merle gene creates mottled patches of color in a solid or piebald coat, blue or odd-colored eyes, and can affect skin pigment as well. Health issues are more typical and more severe when two merles are bred together, so it is recommended that a merle be bred to a dog with a solid coat color only. Merle can affect all coat colors. The merle forms of brown and black are usually called liver (or red) and blue, respectively. Dogs who are recessive red can still be affected by merle, but the patches are either hardly seen or if the dog is a clear recessive red, it is not visible at all. Combinations such as brindle merle exist, but are not typically accepted in breed standards.
In addition to altering base coat color, merle also modifies eye color and coloring on the nose and paw pads. The merle gene modifies the dark pigment in the eyes, occasionally changing dark eyes to blue, or part of the eye to be colored blue. Since merle causes random modifications, however, both dark-eyed, blue-eyed, and odd-colored eyes are possible. Color on paw pads and nose may be mottled pink and black.
Day 3; The Merle Gene and Eye Abnormalities
The Merle gene is directly responsible for a wide variety of beautiful coat and iris colors in the dog. This dilution gene acts to lighten the coat color. The dappling effect it creates is not evenly spread; rather, it is responsible for spotting of the coat and variations of the iris or colored part of the eye. Unfortunately, the same gene that is responsible for the desirable coat and eye appearance is often responsible for MANY developmental eye defects.
With respect to ocular effects, the Merle gene’s most minor manifestation is a blue iris. There is no adverse consequence of the presence of the blue iris alone but the other effects of the Merle gene may result in devastating blindness. The abnormalities affect either the front or back part of the eye or BOTH. When the whole eye is affected, the condition has been referred to as Merle Ocular Dysgenesis.
There are many serious ocular problems associated with the Merle gene.
Microphthalmia is a congenital defect characterized by a small eye. Severely affected dogs may be blind at birth. The optic nerve’s job is transmission of information from the retina to the brain for the interpretation of vision. When a defect at this level of the eye is minor, a patient remains visual; alternatively, a more serious defect of the optic nerve will be the cause of complete blindness.
In addition to the optic nerve, the retina may also be affected negatively.
Retinal dysplasia is abnormal development of the sensory retina with focal folds or widespread geographic maldevelopment.
With an array of problems that may have a common end result of blindness, ethical breeders will not breed affected animals because those with ‘mild disease’ may still produce severely affected offspring. But beware of the byb or pet store puppies that have limited veterinarian care during gestation and often times have no medical history of the breeding pair. It is always ideal to have breeding animals evaluated by a veterinary ophthalmologist to rule out structural abnormalities of the eyes. These exams DO NOT guarantee that the dog is not a carrier of genetic ocular disease; rather, a passing test proves that at that time of exam no genetic ocular disease was diagnosed. If a dog’s status is unknown, it is strongly recommended not to breed. With respect to the Merle gene and ocular dysgenesis, these abnormalities are congenital, which means they are present at birth. These congenital deformities are NOT reversible.
Day 4; Deafness in Dogs Genetics
Congenital deafness in dogs can be acquired or inherited. Merle patterned dogs are most likely to be a carrier of Inherited deafness caused by poor breeding practices. Deafness may have been long-established in a breed but kept hidden from outsiders to protect reputations. The disorder is usually associated with the presence of white in the hair coat. Two pigmentation genes in particular are often associated with deafness in dogs: the merle gene and the piebald gene. The deafness, which usually develops in the first few weeks after birth while the ear canal is still closed, usually results from the degeneration of part of the blood supply to the cochlea.
It should be noted that a deaf dog can be a great genetic risk for transmission of deafness to its offspring.
Simple genetics shows both parent dogs can be carriers without actually being noticeably deaf themselves.
Deafness is most often associated with the merle (dapple) gene and the carriers are often deaf and blind, and are sterile. Breeders of these dogs know not to breed but are usually overtaken with the profits to selling these color patterns.
What a SHOCK for the buyer expecting a normal, healthy puppies!
Personal story of buyer
With a very heavy heart and just know life sometimes isn’t fair!! We had to put our puppy down today. Our sweet Dexter!!! He was perfect in every way. He was beyond beautiful, so so sweet, a lover and so much personality. We bought Dexter from a Frenchie breeder in Corsicana, Texas. He at just 8 wks old was perfect although we didn’t know his beauty n coloring gave a severe birth defect in his eyes. Blue Merle have a known problem with their eyes. Dexter began to squint then blood filled eyes, both detached retinas and severe glaucoma that put pressure on his eyes severely. Not only that we discovered numerological issues n hydrocephalus or water on brain then heart disease. We watched him deteriorate. We found a potential eye surgeon only 4 on the planet to look at case n arranged flights but his eyes to far gone then the brain surgery n then eyes removed. We love love our animals. In a gut wrenching decision we decided to put our Dexter down. So very sad!! We will never forget our short time with him. RIP our beloved Dexter!! Please do your research in buying puppies especially Blue Merle dogs. Especially French Bulldogs. Unfortunately our breeder offered no sympathy and did nothing. It hurts to know that some breeders dont stand behind their pups especially expensive dogs. I hope Frank Agee doesnt sell another dog!! We took our dog to our great long time vet from day one n as we noticed things we notified breeder thru multiple eye specialists 2nd n 3rd opinions n just couldn’t believe this was happening to this beautiful baby. Special thanks to Dr. Mark Allen Companion Animal Hospital in Plano and Dr Stephanie Beaumont Animal Eye Specialists in Plano and all the family and friends who were involved!! We love you Dexter and hope you are in peace and a better place!!🙏🙏🙏
