From wikipedia: The gray gene (G) is an autosomal dominant gene. In simple terms, a horse which has even one copy of the gray allele, even if it has a gene for another coloring, will always become gray. If a gray horse is homozygous (GG), meaning that it has a gray allele from both parents, it will always produce gray offspring. However, if a gray horse is heterozygous (Gg), meaning it inherits one copy of the recessive gene (g), that animal may produce offspring who are not gray (depending on what color gene an offspring inherits from its other parent). Conversely, a gray horse must have at least one gray parent. Genetic testing is now possible to determine whether a horse is homozygous or heterozygous for gray, or if it does not carry the gene at all. The gray gene does not affect skin or eye color, so grays typically have dark skin and eyes, as opposed to the unpigmented pink skin of white horses.
In 2008, researchers at Uppsala University in Sweden identified the genetic mutation that governs the graying process. The study also revealed that gray horses carry an identical mutation that can be traced back to a common ancestor that lived thousands of years ago. The discovery that gray can be linked to a single animal provides an example of how humans have "cherry-picked" attractive mutations in domestic animals. Gray is controlled by a single dominant allele of a gene that regulates specific kinds of stem cells.
In 2008, researchers at Uppsala University in Sweden identified the genetic mutation that governs the graying process. The study also revealed that gray horses carry an identical mutation that can be traced back to a common ancestor that lived thousands of years ago. The discovery that gray can be linked to a single animal provides an example of how humans have "cherry-picked" attractive mutations in domestic animals. Gray is controlled by a single dominant allele of a gene that regulates specific kinds of stem cells.
The identification of the gray mutation is also of great interest in of medical research since this mutation also enhances the risk for melanoma in horses; About 75% of grey horses over 15 years of age have a benign form of melanoma that in some cases develops into a malignant melanoma. The study of gray genetics has pointed to a molecular pathway that may lead to tumour development. Both STX17 and the neighboring NR4A3 gene are overexpressed in melanomas from gray horses, and those carrying a loss-of-function mutation in ASIP (agouti signaling protein) had a higher incidence of melanoma, implying that increased melanocortin-1 receptor signaling promotes melanoma development in Gray horses.
Today, about one horse in 10 carries the mutation for graying with age. The vast majority of Lipizzaners are gray, as are the majority of Andalusian horses. Many breeds of French draft horse such as the Percheron and Boulonnais are often gray as well. Gray is also found among Welsh Ponies, Thoroughbreds, and American Quarter Horses. All of these breeds have common ancestry in the Arabian horse. In particular, all gray Thoroughbreds descend from a horse named Alcock's Arabian, a gray born in 1700. The gray coat color makes up about 3% of Thoroughbreds.
This is Annie when I first got her. She was four years old and already gray.
Today, about one horse in 10 carries the mutation for graying with age. The vast majority of Lipizzaners are gray, as are the majority of Andalusian horses. Many breeds of French draft horse such as the Percheron and Boulonnais are often gray as well. Gray is also found among Welsh Ponies, Thoroughbreds, and American Quarter Horses. All of these breeds have common ancestry in the Arabian horse. In particular, all gray Thoroughbreds descend from a horse named Alcock's Arabian, a gray born in 1700. The gray coat color makes up about 3% of Thoroughbreds.
This is Annie when I first got her. She was four years old and already gray.
(Aw, look at that tail! Her poor tail is nonexistent nowadays!)
This is Annie now. Please excuse the "baby" belly. lol!
This is Shahreen, a 17 year old half Arabian. She was flea bitten when I owned her. Her base coat was golden, like a palomino and I was told that she had two palomino foals. I believe the stud was a chestnut. 
This was Shannon, a dapple gray Thoroughbred. She was 5 in this photo. By the time I sold her at 8, her mane and tail were already graying and her body was a lighter dapple color. I am sure she would turn mostly "white" when she got older. 
Since Yalla! was born dun color rather than dark,
and is now darkening up with no visible white hairs coming in, I believe she will be a dark brown or black bay like her father.
Of course, I could be wrong! Only time will tell.
You're just a little girl with gray - song: What in the World, artist: David Bowie, album: Low
Then my two sons, Trevor and Ross, and Ross's girlfriend took me to the movies. We saw 
I came across these pictures (click 
When the foal refused to move forward, Jeff suggested just waiting it out, all day, if need be. He says to keep a steady pressure on the rope and eventually the horse will give in to the pressure and step forward. I guess it usually works, but not with Timmy!
He just closed his eyes and thought about taking a nap.
Jeff pulled harder and Timmy braced back, closed his eyes and prepared to spend all day there too, never intending to move. LOL. A clinician's nightmare! 
Because, this was a clinic, he had to give up and go on to other things. Too bad, Timmy won!
While I was feeding them the other day I noticed a lump/knot on Annie's back leg. I don't know what happened but I figured it might feel good to get some liniment on it. Notice the strange pattern of veins to the front of it.
So I pulled out the ol' jug of horse liniment. I love the smell of liniment, don't you?
Maybe if I keep massaging it the knot will go away. Liniment tends to bring warmth and thus, blood, to any pained areas so maybe it will help heal it. I don't know, but she sure enjoys it. Hmmm, I wonder if I should throw some liniment in a bucket of water and give her an all over rubdown. I'll bet she'd LOVE it.
