Merle Great Dane – Everything you Need to Know

Merle Great Dane

What is a Merle Great Dane?

A Merle Great Dane refers to a unique pattern that is caused by a specific gene. This Gene is referred to as the Merle gene and is a dominant gene meaning it only needs to be passed on by one parent. Due to this only needing to be passed on by a single parent there is no need to breed two carriers together.

The Merle pattern itself appears as patches of darker fur across the Great Dane. This often is described as a marbling effect due to the pattern being different and unique on each dog. There are however usually some similarities this is often smaller patches around the face and larger on the body, although this is not an exact rule.

With Merle being a Dominant gene it is fairly easy to produce Merle puppies from any Merle dog. Breeding a Merle dog with any Non-Merle will give you around a 50% chance of producing Merle offspring. If looking to produce Merle dogs it would be tempting to breed two Merles together. There are however health reasons as to why this should not be done. Merle dogs with two copies of the Merle gene can have significant health issues. These are referred to as Double Merles, for this reason you should never breed two Merles together. There is around a 25% chance of a puppy being a Double Merle if they have two merle parents. If you are looking to breed and are unsure if you’re dog carries a Merle gene then you should carry out a DNA test

What are the different type of Merle’s you can see in a Great Dane?

Blue Merle Great Dane

The Blue Merle Great Dane requires the dominant Merle gene in addition to the recessive Blue gene. The Blue gene is known as the dilution gene and is located in the D Locus. Due to this gene being recessive, it requires both parents to pass on this gene to produce a Blue Merle Great Dane Puppy.

The pattern on a Blue Merle Great Dane is similar to that of an ordinary Merle. It will appear in random spots across the body in a marbling style effect. The difference is that the base coat will be Blue and the spots on the coat will be a darker Blue. Due to the rarity of the Blue gene it is rare to see Blue Merle Great Danes and often come at a premium price.

It is important to not breed Merle dogs with any other Merle dogs. This is to avoid the risk of producing a Double Merle. The base color of Merles being different has no effect on this risk. This means breeding a Blue Merle with a regular Merle will still have a chance to produce Double Merles.

Blue Harlequin Great Dane

The Blue Harlequin Great Dane has many similarities to that of the Blue Merle. This is due to the Harlequin pattern not being visible without also the Merle gene being present. The Harlequin pattern itself makes the marking from Merle larger in size and more consistent across the body. This turns the marbling effect of the Merle pattern into more of a large polka dot pattern which is similar to that of a Dalmatian.

The Harlequin gene is a dominant gene meaning only one copy needs to be present in a Great Dane. Due to this requirement it means only one Harlequin Great Dane needs to be present in breeding to produce offspring. Unfortunately similar to the Merle gene there are health issues related to the gene. Whilst a single Harlequin gene does not appear to have any significant health concerns linked. A dog with two copies of the Harlequin gene is unlikely to make it to birth. There aren’t currently any known Double Harlequin dogs because of this. When breeding any Harlequin dog it is incredibly important not to breed with another Harlequin.

The Harlequin pattern itself is linked to the Merle pattern. This does not mean however that you can’t have a Harlequin Great Dane without a Merle gene. In the case where the Harlequin gene is present without Merle the normal coat color will display. This will result in a hidden Harlequin gene and due to potential health defects of Double Harlequin it is important to DNA test before breeding.

Double Merle Great Dane

A Double Merle Great Dane is unfortunately a dog that is likely to have a number of health issues. The expected lifespan of a Double Merle can vary but is usually under five years. The pattern itself on these dogs is usually the reverse of a regular Merle. This would appears as a dark coat with white patches but can vary.

Due to a Double Merle being caused by the combination of two Merle genes it is simple to avoid. If a Merle is bred with only Non-Merles then there won’t be any Double Merles produced. If a breeder is seen selling Double Merles then this should be a red flag around their breeding practice.

Are Merle Great Danes Healthy?

It is difficult to know if single Merle Great Danes have health issues although studies have indicated generally Merle dogs have a higher risk of health issues.

Some of the Health issues linked to the Merle gene are the following.

  • Deafness – There is an increased risk of deafness or hearing issues compared to a regular Frenchie
  • Blindness – Dilation of the pupils can be an issue which can lead to night blindness and in some cases complete blindness.
  • Further Eye Issues – There is also a risk of eyes being off centre, additional eyelids, missing tissue or in some cases being born without eyes.
  • Immune Deficiency – A high risk of a having a weakened immune system.

The above are highly likely to occur in Double Merle Great Danes with the majority being deaf.

Great Dane Health Issues

Great Danes like most dogs can suffer a range of health issues with many related to their large size. Below we outline some of the more common afflictions. These are in addition to the Merle Health Issues.

Hip Dysplasia 

This leads to a reduced range of movement in the hind legs along with a reluctance in jumping, running and climbing stairs. Ensuring they stay at a healthy weight and are fed a high quality diet will help delay the onset.

Gastric Dilation Volvulus (GDV)

This is largely associated with eating large meals rather than several smaller meals. Studies have shown that dogs which are fed one large meal a day are more likely to be afflicted. In addition it has been observed that foods high in oils such as sunflower or animal fat can be a contributing factor. Whilst this illness can be life threatening in the worst of cases there are additional ways to reduce the risk. Elevated feeding is recommended as a way to reduce this pressure in addition to several meals a day.


Great Danes can be prone to allergies like most other dog breeds. This will usually display in red/raw patches often around their paws. Also it can show through watery eyes, ear infections or sneezing. If you suspect allergy issues it is best to discuss with a vet around possible treatments.

Heart Disease 

Great Danes can be prone to Heart disease, the best way to reduce this risk is through breeding. It is important to find out the medical history of any puppies parents as this will be the best indicator of risk.

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