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Merle Bully – Everything you Need to Know

Merle American Bully

People find the Merle Bully highly desirable due to it’s unique color. There are however a number of ethical issues around adopting one due to the increased health issues of the Merle gene.

What is a Merle Bully?

A Merle Bully refers to a Bully which has a specific gene which causes mottled patches of color. Merle can appear in a number of different ways due to characteristics of other coloring still being present. This means that you can still expect to see either a solid color or piebald effect outside of these patches. They are also recognisable by their eyes where they will often have one or two bright blue eyes.

The most common colors to see within Merle are Red Merle and Blue Merle. Red Merle the mottled colors are faded less and therefore the markings aren’t very clear. On a Blue Merle the mottled colors show in a much clearer fashion, this also gives a Tri color effect without the Bully being a true tri-color.

You should expect a Merle Bully to retain the normal characteristics found in the respective Bully breed. The below chart outlines the expected weights from Micro through to XL sized Bullies.

Pocket American BullyStatistics
Weight20 – 65 Pounds
Height13 – 17 Inches
Lifespan10 – 12 Years
Merle American BullyStatistics
Weight65 – 85 Pounds
Height17 – 20 Inches
Lifespan10 – 12 Years
American Bully XLStatistics
Weight85 – 150 Pounds
Height20 – 23 Inches
Lifespan10 – 12 Years

There is no genetic reason as to why any size of Bully can’t be Merle.

How do you breed Merle dogs?

Merle Bully

Their are a number of ways Merle dogs can be made dependent on their parents genetics. In order to be Merle they need to have a positive Merle gene and a negative Merle gene M/m. This means that if 2 Merles breed there will be a 50% chance of a Merle being born, 25% chance of a Non-Merle and a 25% chance of a Double Merle.

In addition to Merle coated Bullies being able to produce Merle puppies there are also hidden carriers. These are called Cryptic carriers. They won’t show any Merle markings but will have the ability to produce Merle offspring. It is possible that two Non-Merle Bullies could produce a Merle puppy.

There are further complexities associated to the genetics around Merle and if you have a keen interest in the scientific information behind this then Paw Print Genetics have written a good article you should read. If you want to check your own dogs DNA then we would recommend carrying out a DNA Test

What’s the difference between Merle and Double Merle?

The difference relates to how many negative or positive Merle genes a Bully possesses. If we take the positive Merle gene M and the Negative Merle Gene m the can be 4 different combinations. M/M double positive will produce a Double Merle. M/m and m/M will produce the look people associate with Merle. m/m will produce a Non-Merle.

Any Bully which has a positive Merle gene M has a higher health risk, having two positive Merle gene a Double Merle will have a large increase in health issues.

Health Issues

Merle Bully

In the majority of cases you should expect a Merle Bully to be as healthy as a regular colored Bully. There is however an increased risk in some Merles. The increased risks which can be found in Merles are listed below.

  • Deafness – There is an increased risk of deafness or hearing issues compared to a regular Bully
  • 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

All of the issues listed above go from being rare in a Merle Bully to common in a Double Merle, this highlights why it is so dangerous to breed when it could result in a Double Merle.

In addition to the increased risks Merle Bullies are also at risk of health problems common to all Bullies such as:

Hip Dysplasia – This leads to a reduced range of movement of the hind legs along with a reluctance in jumping, running and climbing stairs. It can be very painful for the dog and will usually present later in life.

Heart Disease – Bullies can be prone to heart disease including a congenital heart disease in the form of aortic stenosis. Whilst it may not be possible to avoid heart disease in dogs there are steps that can be taken. These include regular exercise and feeding your dog a diet which contains enough taurine and omega 3.

Skin Infections – There are a wide range of different skin issues which can affect a Bully such as Dermatitis, Mange, Dry skin and Allergies.

Why do people breed Merles?

It is difficult to answer this as it can differ in each individual case. Kennel clubs will not recognise Merle Bullies due to the additional health concerns that come along with them. Due to this there is no encouragement to breed these for shows.

Any breeding should have a clear focus on ensuring the health needs of any puppies are met. Anyone purposely breeding Merles will be failing in this duty due to the known extra health issues of a Merle. There isn’t any evidence that merles have a better temperament or higher intelligence which could be factors in selective breeding.

The likely reasons people breed Merle dogs is in the best case ignorance but is usually down to greed. Currently Merle puppies sell for around a 5x premium compared to a regular colored Bully. This means that a breeder who breeds 2 Merles and has a fairly standard 4 puppies can expect 2 Merles which will fetch more than double the amount of a regular colored litter of 4. It is likely that a Double Merle would be born and likely culled due to a no-one being willing to purchase a dog with health issues.

Should you adopt a Merle Bully?

Due to the health concerns around Merle Bullies it’s not possible to make an argument for breeding on health grounds. If you have any plans on breeding then a Merle Bully is not for you. If you purchase from a breeder who is breeding two merle Bullies then you are supporting this unethical breeding practice. There are however incidences where Merle Bullies are created without any intention. There is no reason as that you shouldn’t adopt in this case as long as you are prepared for an extra burden of health issues.

In summary it is best to avoid Merle Bullies to not encourage breeders to breed them. If you do decide to purchase a Merle then you should be prepared for an additional healthcare burden when compared to a regular Bully.

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