Do Merle Great Danes Have More Health Problems?

The Merle Great Dane has a distinct coat pattern of a pale to dark grey coat that is covered with dark marks.

The question is, does having this Great Dane coat color and the genetics behind it cause the Merle Great Dane to have more health problems?

Do Merle Great Danes have more health problems?

Below, we will look into the Merle Great Dane’s health and determine if they have more health problems compared to other Great Danes.

Double Merle Great Danes have more health problems than single Merle Great Danes because of the merle gene which is associated with decreased effectiveness of the immune system, ear and eye deformities, sun sensitivity, and skin cancer.

Although all Merle Great Danes are at risk of developing these health problems they are more likely to occur in a double Merle Great Dane than a single Merle Great Dane.

Do Merle Great Danes Have More Health Problems

Causes of Health Problems In Merle Great Danes

A puppy inherits two copies of a gene, that is, one from each of his parents. For the Merle Great Dane, there is a merle gene (M) and a non-merle gene (m). 

If a puppy gets two copies of the Merle gene (M), they are considered a double merle or homozygous (MM). Double merles usually have a partially or completely white coat with blue or pale blue eyes. 

If a puppy inherits one non-merle gene and one merle gene (M), they are considered heterozygous (Mm). In this case, the merle gene will be dominant and the coat color will be merle with a dilute coat and possibly different colored eyes. Merles commonly have blue eyes, sometimes one brown eye or one blue eye or two brown eyes.

Research has shown that the merle gene is linked to a higher rate of eye and ear impairments.

Although Merle Great Danes are at risk of developing the health problems associated with the merle gene, Double Merle Great Danes have a higher risk of developing these health problems because of the two copies of the merle gene that they have.

Therefore Double Merle Great Danes do have more health problems.

Recommended reading: Can you breed a merle and Harlequin Great Danes?

Health Problems Of The Merle Great Dane

The Merle gene is responsible for a Merle Great Dane’s coat color pattern and eye color when the gene expresses itself.

In addition to contributing to the appearance of the Merle Great Dane, research has shown that the gene is linked with the following health problems:

Ear problems

Merle Great Danes have a high risk of developing defects in their auditory system which comprises the ears and parts of the system responsible for hearing. They may suffer partial or complete deafness.

Studies have shown that the merle gene is responsible for hearing impairment in dogs that have the gene.

The research indicates that dogs with the Merle gene have a 2.7% chance of developing deafness while Double Merles have a 10% chance. Therefore the risk of having an ear impairment is twice for a Double Merle Great Dane.

Related: Merle Great Dane vs Harlequin: Top differences

Eye Deformities

The Merle gene is also responsible for the eye color of a Merle Great Dane and has also been linked to causing several eye deformities and causing limited vision or blindness.  

The possible eye abnormalities include:

  • Deformed third eyelid
  • Partial or complete blindness.
  • Night Blindness
  • Clefts in the iris
  • Eyeballs not centrally positioned
  • Cataracts
  • Smaller eye size than normal
  • Missing tissues in the eye
  • Defects in the optic nerve structure
double merle great dane
Double Merle Great Dane with eye deformities

By Eimann, Wikimedia licensed under CC By-SA 2.0 de via Commons

Sun sensitivity and skin cancer

Double merle Great Danes lack pigment in their skin and coat which would protect them from UV light. 

This makes them more sensitive to light which in turn makes them more susceptible to skin cancer and sunburn. The cancers they can develop include squamous cell carcinoma and hemangiosarcoma.

When outside they require shelter to protect their skin. Their skin becomes sensitive to touch after a prolonged period in the sun.

In hot weather to prevent sunburn, they require skin protection by use of a child-safe SPF 30 -50 sunscreen applied to their belly, nose, and other bare patches of their coat without hair. 

Read More: Blue Merle Great Dane

Summary: Is Merle Great Dane Less Healthy?

The Merle Great Dane is not less healthy than any other Great Dane with a different coat color pattern. They live perfectly healthy lives. The Merle Great Dane does have a risk to the development of health conditions due to the Merle gene however they do not necessarily develop these health problems. 

The problem comes in if the Merle Great Dane is a double Merle. Double Merle Great Danes are at a greater risk of developing health problems than single Merle Great Danes. 

The only way of avoiding these health problems is through responsible breeding to prevent the production of Double Merle puppies.

This shows the importance of purchasing a puppy from a reputable breeder who carries out the necessary genetic tests before breeding. 


Related Posts