What is a Grulla horse and why are they so unique?
This rare horse is one of the most beautiful colors.
But where does this coat color come from and what are the unique characteristics they have?
Find out what makes Grulla horses special right here in my guide.
What is a Grulla Horse?
You might think that a Grulla horse is a specific breed. However, it is actually a color that certain breeds of horses can have.
To get this color certain genes must into come into play. This is the dune gene.  The dune gene is not one of the main base horse coat colors but a dilution gene that affects how the base color is expressed. 
These horses not only have a unique sooty tone to the color of their hair, but they also exhibit a specific color pattern.
You can only get the Grulla color when mating a black horse with a red (chestnut) or dun mare. In addition, the dilution gene also needs to be passed from one of the parents.
You can’t guarantee you’ll get Grulla by doing this, however.
A dun gene, when mixed with the basic color of a horse, tones down the horse’s basic color resulting in diluted coat colors. It also dilutes black pigments in the coat creating a sort of gray tone.
Grulla horses are otherwise known as mouse dun, blue dun, or gray dun, depending on the shade expressed.
What should have been a black coat turns out to be a gray color instead along with other markings typical of a Grulla horse.
The gray of a Grulla is not the same as a true gray horse the gray gene. Gulla horses look like a solid gray but are not actually gray.
READ MORE: What are the 5 basic horse coat colors?
Learn more about horse coat color genetics in this great introductory video.
Origin of the Word Grulla
The word ‘gulla’ has Spanish origins.  How it became associated with a horse coat color is a bit of a mystery, as the word means ‘crane.’
It certainly doesn’t come from the unique physical characteristics you will see on these horses, which I’ll talk about next.
READ MORE: What is a Piebald Horse?
4 Physical Characteristics of Grulla Horse
Grulla horses are known for their distinct colors and beautiful markings.
Although there may be many horses that will mimic the colors of a Grulla horse, it is not a true Grulla unless it carries both the dun and black genes.
Let’s take a closer look.
1. Grulla Colorations
Gulla horses have primitive markings which separate them from most other horses. Their main coat collar distinguishes them from other colors that also have primitive markings, such as the buckskin color.
There are many shades of Grulla but all of them will have some tinge or hint of black.
They can come in chocolate brown, champagne, painted, silver dappled, blue, light gray, or even shades that are nearly entirely black or white.
For a horse to be considered a Grulla horse, it must have these distinctive markings:
- A head that is distinctly darker in shade compared to the rest of the horse’s body
- Ears with dark tips
- Legs that are dark in color – usually with black markings or those that are a dark shade of brown
- A dorsal stripe. This is a dark stripe which runs along the back of the horse all the way to the tail
There are also minor varied markings that may accompany these major markings in a Grulla horse, such as:
- The presence of stripes along the legs
- Dark mottling patterns found on the legs and shoulders of the horse
- Dark rings surrounding the eyes
- Shoulder stripes, and/or stripes on areas such as the forehead, neck, and back.
- Guard hairs in the mane or tail that are colored white or cream
A dun horse is any horse that has a basic coat color that is lightened due to the dilution gene, the dun gene.
Base coat colors for all horses are either red, bay, or black.
When the base color is black with the presence of a dun gene you have some chance of creating a Grulla horse.
Since a Grulla horse is actually a black horse, expect a dark mane and a dark tail.
For some great name ideas for your equine, check out this video:
How to Tell if Your Horse is a Grulla
Grulla horses can be quite difficult to produce. Determining whether a horse is a Grulla or not is not always easy to prove, just by looking at it.
To begin with, a foal coat may initially appear to be Grulla but may turn out to be a plain black horse after shedding. Many horses that are black are actually born with a silvery foal coat color.
So how can you know if your horse is truly a Grulla or not?
The best and probably only way to know if a horse is a Grulla or not is to perform genetic testing or horse color testing.
A Grulla horse must have both the dun gene and a black gene in order to be considered a true Grulla. This can only be confirmed through genetic testing.
Cute Pictures and Videos of the Grulla Horse
Curious about what a Grulla horse looks like? Check out these pictures and videos below.
#1 This Grulla horse with that beautiful bluish-black mane and tail.
#2 A team of Grulla horses.
#3 Grulla horses in action
#4 A silver Grullo, one of the rarest shades of this coat color
Grulla Horse Behavior
Since a Grulla horse is not a specific breed, its behavior will really depend on the actual breed of the horse.
Grulla refers only to the horse’s color. The genetic combination will not affect its temperament or behavior.
Grulla Horse Health
The combination of genes in a Grulla horse is not known to affect its health. As long as the Grulla horse is properly cared for, it should be as sturdy as any other kind of horse.
How Much is a Grulla Horse?
Grulla horses can cost anywhere from $5000 — 15000.
Where and How Can You Get a Grulla Horse?
You can buy a Grulla horse from any established breeder. You may also check online for Grulla horses but make sure to do your due diligence before making any purchase.
Don’t forget to check out these cool names for chestnut horses too!
How rare is a Grulla horse?
A Grulla horse is quite rare since breeding a black stallion and a mare with a dun gene will not always result in a Grulla horse.
What horse breeds can be Grulla?
Grulla coloring is found in several horse breeds, but not in all of them. Horse breeds where you might see this color include the American Quarter Horse, the Highland Pony, the Heck Horse, the Welsh Pony, and the Connemara Pony. There are no Thoroughbred Grulla horses.
What’s the difference between Grulla and Grullo?
The difference between Grulla and Grullo is simply one is the female and one if the male form of the word. Other than that, they mean the same thing.
How do I breed a Grulla?
The breed a Grulla, you need a horse that is carrying 2 recessive black genes (a/a) which are the genetics for a true black. You then need to include at least one modifier gene. In this case the dun gene. However, there is no guarantee you will get grulla. 
A Grulla horse is often mistaken for a breed of horse. However, don’t let that confuse you. When someone talks about a Grulla horse, it is actually referring to the coat color and markings, rather than a breed.
Grulla horses are hard to reproduce making them extra special, especially with equine lovers who like unusual colors.
Do you know how to spot a Grulla Horse? Let us know how down in the comment section!
- “Dun Dilution | Veterinary Genetics Laboratory.” Vgl.ucdavis.edu, vgl.ucdavis.edu/test/dun-horse#:~:text=Dun%20is%20a%20coat%20color. Accessed 8 Apr. 2022.
- Dilute Coat Colour about the Colour. www.langfordvets.co.uk
- “Collins.” Collins Dictionary, www.collinsdictionary.com/dictionary/spanish-english/grulla. Accessed 8 Apr. 2022.
- horseshoeangusranch. “The Basics of Black and How to Get a Grulla.” KT Ranch, 10 June 2016, ktranch.com/2016/06/10/the-basics-of-black-and-how-to-get-a-grulla/. Accessed 8 Apr. 2022.
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