Merle Pitbull’s are in demand due to their unique coloring. 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 Pitbull?
A Merle Pitbull refers to a Pitbull 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.
Pitbull itself can refer to a number of different breeds, whilst it most commonly refers to the American Pit Bull Terrier it can also include the following breeds.
- American Pit Bull Terrier
- American Staffordshire Terrier
- Staffordshire Bull Terrier
- American Bully
You should expect a Merle Pitbull to retain the normal characteristics found in the respective Pitbull breed and unless specifically bred to be a Pocket/XL variant then you should expect them to fall into the below Height/Weight Charts.
Merle American Pit Bull Terrier | Statistics |
Weight | 30 – 65 Pounds |
Height | 17 – 20 Inches |
Lifespan | 10 – 12 Years |
Merle American Staffordshire Terrier | Statistics |
Weight | 50 – 80 Pounds |
Height | 17 – 19 Inches |
Lifespan | 12 – 14 Years |
Merle Staffordshire Bull Terrier | Statistics |
Weight | 24 – 38 Pounds |
Height | 14 – 16 Inches |
Lifespan | 12 – 16 Years |
Merle American Bully | Statistics |
Weight | 65 – 85 Pounds |
Height | 13 – 20 Inches |
Lifespan | 10 – 12 Years |
How do you breed Merle dogs?


The Merle gene has both a positive and a negative variant. The positive variant is where the majority of health concerns lie and if you see a Merle Pitbull it will likely have one positive and one negative gene M/m. If two Merles are bred together there is a 50% chance to produce offspring with the same genetic make up of M/m which is viewed as the traditional Merle coloring. There is however a 25% chance of producing a Double Merle M/M which has very high health risks.
Some dogs can carry the Merle gene whilst not displaying the Merle coloring these are referred to as Cryptic. This gene is commonly found in Pitbull’s with solid colors. Due to these dogs possessing the Merle gene it is possible for any offspring to be born with Merle colorings especially if bred with a Merle Pitbull. Whilst it is unlikely due to the genetics in Cryptic Pitbull’s it does also mean there is a very low chance of Merle offspring being produced by parents who show no Merle coloring.
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.
Do Kennel Clubs recognise Merle Pitbull’s
Merle is not recognised by any National or Pitbull Kennel Clubs. This is due to the increased health risks around this genetic make-up. Any color combination that isn’t recognised by a Kennel Club is usually an indicator of issues around the breed being produced with those genetics. This can be due a number of reasons such as whether it is purebred or health issues. Merle isn’t recognised by Kennel Clubs down to the health issues surrounding it.
What’s the difference between Merle and Double Merle?
When we typically refer to a Merle Pitbull we are talking about the possession of one positive and on negative gene M/m. This displays the Merle coat in the ways we have outlined so far through this article. This means mottled patches of fur displaying in a different color in addition to either a solid or piebald coat dependent on the rest of the Pitbull’s genetics.
A Double Merle Pitbull refers to when there are two positive Merle genes M/M. Double Merles are associated with having a large increase in a number of health issues. It is widely accepted that breeding dogs where there is a known chance of producing a Double Merle to be unethical. A Double Merle will present itself with a largely white coat with small patches of darker fur. This is recognizable as being effectively the reverse coloring seen in a regular Merle.
Health Issues
In the majority of cases you should expect a Merle Pitbull to be as healthy as a regular colored Pitbull. 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 Pitbull
- 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 Pitbull 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 Pitbulls are also at risk of health problems common to all Pitbull’s 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 – Pitbull’s 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 Pitbull such as Dermatitis, Mange, Dry skin and Allergies.
Training and Exercise Requirements
It is vital to start training early in puppyhood as this is when your Pitbull is most receptive, in addition to this as soon as they have received their vaccinations you should begin socialization with other dogs. A great option to tick both of these boxes is to enrol in puppy play time activities (Often held by local pet stores) or puppy training classes. To successfully socialize it is important that you are in control at all times.
Consistency – Consistency is a word you will here a lot when it relates to training and it is true that consistency is key. Your Pitbull needs to understands the consequences of it’s actions and if this changes each time it can be very confusing. Setting expectations and enforcing these are important for it to understand how it should interact in different situations. This means if you want to train your Pitbull to stay off the couch, you should not make exceptions.
Positive Reinforcement – Positive reinforcement is proven to be comfortably the most effective method of training. It also has the added benefit of being the most pleasant for both the trainer and trainee. Whenever your Pitbull displays the correct behaviour they should be rewarded, this is most commonly reinforced using treats but can also be done using other means such as clicker training. Pitbull’s are loyal and eager to please so will be very receptive to training when young, if left to late it will be more difficult to overcome behaviours which are already bedded in.
Keep them engaged – Keep them engaged by combining both physical and mental stimulation. If your dog is not getting enough exercise or mentally engaging activities they are likely to be less responsive. Hiding treats in toys for them to find, introducing them to new smells by visiting new places and making them follow commands are just as effective as letting them run around when it comes to meaningful engagement.
Should you adopt a Merle Pitbull?
Due to the health concerns around Merle Pitbull’s it’s not possible to make an argument for breeding on health grounds. If you have any plans on breeding then a Merle Pitbull is not for you. If you purchase from a breeder who is breeding two merle Pitbull’s then you are supporting this unethical breeding practice. There are however incidences where Merle Pitbull’s 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 Pitbull’s 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 Pitbull.