color / genetic testing
BASIC BODY COLORS OF THE AUSTRALIAN SHEPHERD
This writing is meant to be as basic as possible with no use of technical terms. It is meant to answer some questions ASCA receives and to help the novice and beginning breeder. The information contained here is regarding the BODY COLOR of Aussies without discussion of white or copper trim.
THE BASIC BODY COLORS OF AUSTRALIAN SHEPHERDS ARE RED & BLACK
1. THE BLUE MERLE IS GENETICALLY A BLACK DOG POSESSING A MERLE GENE (which breaks up the black color into a pattern of black and gray patches). The gray shade may range from light silver to a dark gray.
2. THE RED MERLE IS GENETICALLY A RED DOG POSESSING A MERLE GENE (which breaks up the red color into a pattern of red and beige patches). The beige shade may range from a light ivory to a dark tan.
IMPORTANT!! IN THIS WRITING, BLACKS REFERS TO BOTH SOLID BLACKS AND BLUE MERLES. RED REFERS TO BOTH SOLID REDS AND RED MERLES.
Remember, all blacks and blue merles have black noses and eye rims, and all reds and red merles have liver (brown) noses and eye rims.
In the breed, there are non-recognized colors which are considered undesirable. These colors are disqualifying faults per the ASCA Breed Standard. These include sable, brown merles, brindle, gray/slate, diluted red, and yellow. The genetics of these colors are not discussed here. The reader should realize that if these colors exist in a properly colored dog’s ancestry they may be produced.
The four recognized colors for the Australian Shepherd are: Black, Blue Merle, Red, and Red Merle. One basic rule of genetics the reader needs to know is that gene pairs determine characteristics like color. ONE GENE COMES FROM EACH PARENT. With color, THE DOMINANT GENE is the one you will SEE. The RECESSIVE GENE is the one trait that you DO NOT SEE UNLESS IT IS PAIRED WITH ANOTHER SAME RECESSIVE GENE.
BLACK IS DOMINANT OVER RED!!!!
Keeping this in mind, the genetics for Aussie colors are constant and simple:
1. A dog with TWO black genes is BLACK/BLACK – its color will be BLACK. This dog only has BLACK GENES to pass on thus ALL of its pups will be BLACK.
2. A dog with ONE BLACK gene and one RED gene is BLACK/RED. – Its color will be BLACK. It can produce both black or red pups. When the BLACK gene is passed on, black pups will result. When the RED gene is passed on, ONLY IF paired with a RED gene from the other parent, will the pups will be RED. These blacks are often referred to as “red carriers” or “red factored”.
3. A dog with TWO RED genes is RED/RED – Their color will be RED. TWO REDS PRODUCE 100% REDS! As you can see, there is no black gene to pass on. If a red is bred to #1 above, all the pups will be black but all will carry the red gene. But if the red is bred to #2 above, both black and red pups may result.
For the breeder, the only real uncertainty arises because #1 (BLACK/BLACK) and #2 (BLACK/RED) look exactly alike. If a black dog has a red parent, it will ALWAYS carry the red recessive gene. However, if it comes from two black parents only test breeding or genetic DNA tests will tell if the dog is BLACK/BLACK or BLACK/RED.
You can see from this that the color of the grandparents or ancestors of the red dogs play no part in the colors they will produce. Red genes are all the dog has to pass on. A red dog from two black parents has the same genetic makeup for color as the red dog from two red parents. Occasionally a red will show up in a long line of only black ancestry. This happens when those black dogs were BLACK/RED and carried the gene down but not seen.
All properly colored Australian Shepherds are ONE of these three!! Remember, each parent possesses two genes for color and each puppy will inherit ONE GENE for color from each parent.
AGAIN, BLACK REFERS TO SOLID BLACK AND TO BLUE MERLES. RED REFERS TO BOTH SOLID REDS AND RED MERLES.
--------originally an ASCA handout in the 1980’s by Terry Martin
MORE AUSSIE COLOR INFORMATION
BET Gene-( Blue Eyed Tri. )
The BET gene(s) is a different gene or a combination of genes that causes blue eyes in Tri's, It is a different gene than the blue eyes in merles caused by the merle gene. Our BET dogs at Flying Walker Toy Aussies are descendants from a lone line of what is known as the "Ghost Eyed line" and traced back to one dog HOWARD'S WANAGI-ISHNA GHOSTEYES.
*The name 'Ghost Eyes' came about back in the day when Native Americans would see our blue eyed Aussies that came over seas herding sheep and called them "Ghost Eyed Dogs"
The S Locus (White spotting)
This dog carries two copies of S which results in a solid coat with no white spotting, flash, parti, or piebald coat color. This dog will pass on one copy of S to 100% of its offspring.
Interpretation: No white spotting, flash, parti, or piebald
This dog carries one copy of S and one copy of sp which results in limited white spotting, flash, parti, or piebald coat color due to the co-dominance of S and sp. This dog will pass on one copy of S to 50% of its offspring and one copy of sp to 50% of its offspring.
Interpretation: Limited white spotting, flash, parti, or piebald (Carrier)
This dog carries two copies of sp which results in a nearly solid white parti, or piebald coat color. This dog will pass on one copy of sp to 100% of its offspring.
Interpretation: Nearly solid white, parti, or piebald
The D Locus (Dilute)
This dog carries two copies of D which does not result in the "dilution" or lightening of the black and yellow/red pigments that produce the dog’s coat color. The base coat color of this dog will be primarily determined by the E, K, A, and B genes. The dog will pass on D to 100% of its offspring.
Interpretation: Non dilute
This dog carries one copy of D and one copy of d which does not result in the "dilution" or lightening of the black and yellow/red pigments that produce the dog’s coat color. The base coat color of this dog will be primarily determined by the E, K, A, and B genes. The dog will pass on D to 50% of its offspring and d to 50% of its offspring.
Interpretation: Non dilute (Carrier)
This dog carries two copies of d which results in the "dilution" or lightening of the black and yellow/red pigments that produce the dog’s coat color. However, this variant modifies or "dilutes" the base coat color of the dog that is primarily determined by the E, K, A, and B genes. The dog will pass on d to 100% of its offspring.
The E Locus (Yellow)
This dog carries two copies of E which allows for the production of black pigment. However, this dog's coat color is also dependent on the K, A, and B genes. This dog will pass E on to 100% of its offspring.
This dog carries one copy of E and one copy of e which allows for the production of black pigment. However, this dog's coat color is also dependent on the K, A, and B genes. This dog will pass E on to 50% of its offspring and e to 50% of its offspring, which can produce a yellow/red coat (including shades of white, cream, yellow, apricot or red) if inherited with another copy of e.
Interpretation: Black (carries yellow)
This dog carries two copies of e which inhibits production of black pigment. The coat color of this dog will be yellow (including shades of white, cream, yellow, apricot). This dog will pass e on to 100% of its offspring.
The Em Locus (Melanistic mask) :
This dog carries two copies of Em which results in a melanistic mask on the muzzle of the dog. However, a melanistic mask may be unrecognizable on a dog with a dark coat color. This dog will pass on Em to 100% of its offspring and will produce only puppies with a melanistic mask.
Interpretation: Melanistic mask
This dog carries one copy of Em and one copy of N which results in a melanistic mask on the muzzle of the dog. However, a melanistic mask may be unrecognizable on a dog with a dark coat color. This dog will pass on Em to 50% of its offspring who will have melanistic masks and N to 50% of its offspring who will have no masks.
Interpretation: Melanistic mask (Carrier)
This dog carries two copies of N which does not result in a melanistic mask on the muzzle of the dog. This dog will pass on N to 100% of its offspring.
Interpretation: No melanistic mask
The T Locus (Natural bobtail) trait test reliably determines if a dog has one of the following genotypes at the T locus:
Interpretation:TT Embryonic lethal
This dog carries one copy of the dominant T allele and one copy of the recessive t allele which produces a natural bobtail. This dog will pass on the T allele to 50% of its offspring and the t allele to 50% of its offspring.
Interpretation: Tt Bobtail
This dog carries two copies of the recessive t allele which results in a tail of normal length (no bobtail). This dog will pass on the t allele to 100% of its offspring.
Interpretation: tt Normal tail
The M locus (Merle gene)
Merle...not so simple
When discovering Aussies the first thing many learn is they come in merles and tris/bis. When the topic of merle arises, many simply know not to cross a merle to a merle. That is about as far into depth as “popular” knowledge of the topic goes. But the topic of merle is an extremely in depth one. You have your non merles, cryptic merles, cryptic+, atypical, atypical+, merles, and then your harlequins.
Non merles (m) typically have 199-200 base pairs. They have no changes to their coat coloration. They are your tri/bi/self colored dogs.
Cryptic merles (Mc) have 200-230 base pairs, they show no differences from that of non merles. When crossed with a merle they can produce the “tweed” pattern.
Cryptic+ merles (Mc+) range from 231-246 base pairs, they also show no coloration differences from non merles. When crossed with merle this cross can produce the widely known “tweed” pattern.
Atypical merles (Ma) range from 245-254 base pairs. They can appear non merle, or have a diluted coat coloration. A black tri may appear a brown/red color. Eyes can be blue at this length without being a blue eyed tri. Crossed with a merle this can cause white body splashes, diluted patches, and may produce “Tweeds.”
Atypical+ merles (Ma+) range from 255-264 base pairs. This is where a merle pattern can be expressed. At this range it is a faint pattern which almost appears as if a film were placed over it.
Others in this range may appear as a tri or diluted coloration to a brown/red color. Eyes can also be blue due to this range. Crossed with a merle they often will have extended white areas, white heads, and diluted coloration. There is a much higher risk of producing the health problems seen homozygous merles at this range, especially when the base pairs reach closer to the upper end.
Merles (M) range from 265-268 base pairs. This is the range that our “normal” merles are in. They have their “black/gray” patterns we know as blue merles or “red/cream” patterns we know as red merles. Eyes are pattern dependent at this range and can even appear marbled. It is widely known not to cross merles together as they produce “double merles” which can be deaf, have eye deformities, and
Harlequin merles (Mh) range from 269-280 base pairs. These can be expressed in three ways, the widely known two being “herding harlequins” with the different colorations and flashy markings or those with white body splashes and flashy contrasting markings. Harlequin merles can also be expressed as minimal merles. When bred to Mc+ or higher there is a much higher risk of excess white.
They should not be crossed with piebald. Dogs on the upper end of harlequin alone can appear as “double merles.” It is recommended to be cautious selecting breeding pairs in this range.
This gets infinitely more complex when you add in the combination possibilities, the fact that basepairs can shorten/lengthen when developing. Typically not by a whole range, but a merle may produce an atypical+ merle due to shortening or the merle sine. To complicate things more, dogs can have more than 2 different merle genes. They can have 3 or 4 different copies of merle (Ie: M/Ma+/Mc/m).
*Base pair counts are based on Vemodia labs values.
All our adult Aussies at Flying Walker Toy Aussies are tested m/m -non merle and m/M -classic merle.
GENETIC HEALTH TESTING
Hereditary Cataract (HC) in the Australian Shepherd is associated with another mutation in HSF4. Cataracts may start forming after 2 years of age and show variable rate of progression and vision impairment. The inheritance of HC in this breed is more complex and this mutation is not the sole determinant for development of cataracts. Other unknown genetic and non-genetic factors contribute to cataract development and progression. The HC mutation in Aussies is mostly associated with bilateral posterior cataracts. Both sexes are equally affected. HC is inherited as a dominant trait with incomplete penetrance, which means that not all dogs that have the mutation will develop cataracts. Dogs that have the HC mutation are 17 times more likely to develop bilateral cataracts compared to dogs that do not have any copies of the mutation. In general, dogs that have 2 copies of the HC mutation tend to have cataracts of the nuclear type, which progresses more rapidly and results in blindness at an earlier adult age. Dogs that have 1 copy of the HC mutation tend to have posterior polar subcapsular type of cataract that is not progressive and does not interfere with vision.
PRA-PRCD: Progressive Rode-Cone Degeneration: is an inherited disease of the retina (the “film in the camera”) in dogs, in which the rod cells in the retina are programmed to die. PRA occurs in both eyes simultaneously and is non painful. Because PRA makes rods die, and rods are responsible for vision in dim light (“night vision”), the first clinical signs that the owner often notices are night-blindness (poor vision in dim light) and that the pupils are dilated; owners often notice a “glow” and increased “eye shine” from the eyes. Clinical signs in dogs with PRA vary from the dog first becoming night blind in the early stage of PRA, to the entire visual field in all light levels becoming affected in advanced PRA. In the final stage of PRA, the dog is completely blind. The natural course of the disease, if specific daily antioxidant supplementation is not given, is that all dogs with PRA will become blind within one year of diagnosis. Sadly, some affected dogs are already completely blind by the time a veterinary ophthalmologist first examines them.
Those not testing and breeding could be producing puppies with this disease. Can you imagine placing a puppy with a family, them all getting attached and then their beloved companion going blind. That’s why everyone should test! You can breed a carrier to a clear and puppies will not be affected but you should NEVER breed carrier to carrier or untested dogs!
CEA-Collie Eye Anomaly: (CEA) is also called "collie eye defect" and is an inherited, developmental disease in dogs. The breeds associated with CEA include:
* Shetland sheepdogs
* Border collies
* Nova Scotia Duck Tolling Retrievers
In CEA, there is a mutation on the gene that determines the development of the eye, and this causes the blood vessels that support the retina to be underdeveloped. The retina may even detach.
In many cases, CEA is not diagnosed until the dog's vision is affected, although there are stages to this disease that ultimately lead to blindness. CEA may be associated with several, more obvious abnormalities in the eye. "Microphthalmia" describes eyeballs that are smaller than normal. "Enophthalmia" describes eyeballs that are sunken deep into the eye sockets. There may be evidence of mineralization in the cornea (surface of the eye) causing cloudiness over the eye. CEA is typically diagnosed by your veterinarian.
CMR1-Canine Retinopathy: is an inherited disorder of the Retina affecting Australian Shepherds. Affected dogs typically present between 11 and 16 weeks of age with multiple discrete circular areas of retinal detachment with underlying fluid accumulation that are visible on an eye exam performed by a veterinarian. These blister-like lesions are typically found in both eyes and can appear gray, tan, orange or pink and vary in number, size and location. Progression of retinal changes is usually slow and new lesions are not noted after 6 to 12 months of age. Occasionally as affected dogs age, lesions appear to heal and are no longer visible on an eye exam. Generally the dog’s vision is not affected although vision loss has been described in some cases of multifocal retinopathy 1.
DM-Canine Degenerative Myelopathy: (DM) is a spontaneously occurring, adult-onset spinal cord disorder that affects dogs, and is similar to Amyotrophic Lateral Sclerosis (ALS) or Lou Gehrig’s disease in humans (1). With DM, there is degeneration of the “white matter” of the spinal cord and the peripheral nerves. The white matter tracts of the spinal cord contain fibers that transmit movement commands from the brain to the limbs and sensory information from the limbs to the brain. Although the disease is common in several breeds, including German Shepherd Dogs, Corgis, Boxers, Chesapeake Bay Retrievers, Rhodesian Ridgebacks, and Standard Poodles, it can occur in other breeds and mixed-breed dogs as well. The typical age of onset is between 8-14 years of age, and both sexes are equally affected. It is a genetic disorder: A genetic mutation has been identified that is a major risk factor for development of DM. Therefore, breeders would do well to take into account DM when establishing their breeding programs. DM, on its own, is not a painful disease. However, compensatory movements for a weak hind end can cause the dog to develop pain in other areas of his body such as his neck, shoulders, and front limbs.
DM typically comes on slowly, almost imperceptibly. Symptoms generally occur as follows:
* Loss of coordination (ataxia) in the hind limbs
* Wobbling when walking and/or rear feet knuckling over or dragging
* Mild hind end weakness such as difficulty in: walking up steps, squatting to defecate, getting into the car
* Can first occur in one hind limb and then the other
* Limbs become weak; dog begins to buckle and has difficulty standing
* Weakness progresses until dog is unable to walk in the hind limbs
* Loss of urinary and fecal continence
* Weakness in front limbs
In general, without intervention, the dog will become paralyzed in the hind end within 6 months to 1 year.
DM is a diagnosis of elimination. This means that your dog’s veterinarian will first look for other diseases that affect the dog’s spinal cord, using diagnostic tests such as spinal x-rays, CT scan, MRI or myelogram. Other conditions with symptoms that are similar to DM’s include a herniated invertebral disc, tumors, cysts, infections, injuries, and stroke. A herniated disc, for example, can put pressure on the spinal cord, resulting in weakness or paralysis. Once the vet has ruled out those diseases, a presumptive diagnosis of DM might be reached. “Presumptive” because the only way to confirm the diagnosis is post-mortem (after the dog has passed away) when the spinal cord can be examined under the microscope. At that time, the vet can look for and identify degenerative changes in the spinal cord that are characteristic for DM and not typical of other spinal cord diseases.
MDR1-Multi Drug Sensitivity: MDR1 is a mutation that causes a dangerous sensitivity to some commonly used medications such as Ivermectin, which is found in commonly used medications for heartworm prevention. The dogs affected by MDR1 are not able to pump these drugs out of the cells as a normal dog would, leading to toxic levels building up within cells. About 50% of Australian Shepherds are affected by MDR1. Carrying one copy of MDR1 is considered affected; however, dogs that are clear have in some cases been known to react to these same drugs.
Sensitivity to (not limited to):
*Acepromazine - prescription tranquilizer
*Butorphanol - pain control
*Cyclosporin - immunosuppressive agent
*Digoxin - used to treat congestive heart failure
*Doxorubicin - cancer treatment
*Doramectin - anti-parasitic medication
*Emodepside - anti-parasitic medication
*Erythromycin - antibiotic used to treat diarrhea, skin infections and prostate infections
*Ivermectin - found in many anti-parasitic medications such as wormers
*Loperamide - found in many anti-diarrhea medications such as Imodium
*Milbemycin - used for treatment and prevention of heartworm
*Moxidectin - anti-parasitic medication
*Paclitaxel - chemotherapy drug
*Rifampin - used to treat many bacterial infections
*Selamectin - anti-parasitic medication
*Vinblastine - cancer treatment
*Vincristine - cancer treatment
For more information about Australian Shepherd's Colors, Diseases and Traits contact Australian Shepherd Health & Genetic Institute, Inc (A.S.G.H.I.) at www.ashgi.org