Why Do Dogs' Fur Change Color?

Adrienne Farricelli

Why do dogs' fur change color? There are several animals whose skin or fur changes color for the purpose of disguising predators making them difficult to see, but contrary to these animals, dogs don't change coat color for the purpose of camouflaging.

Why do dogs' fur change color? There are several animals whose skin or fur changes color for the purpose of disguising predators making them difficult to see, but contrary to these animals, dogs don't change coat color for the purpose of camouflaging.

Many dog owners report that their dog's fur changed color after a surgery or injury causing a dog's fur to turn darker. What happened? Any changes in a dog's fur color are worth investigating as sometimes they can be a sign of something not being quite right. Here are some causes of coat color changes in dogs.

The Aging Process

Humans are not the only ones to age, turns out, dogs age too and when they do, their fur undergoes changes just as in humans. Dogs may not get white hair to the extent of humans, but it's normal to see some graying of the muzzle. As a dog matures, it's quite common for his darkly pigmented coat to attain a lighter color, explains veterinarian Eric Barchas.

This loss of pigmentation in the dog's coat occurs because pigment takes quite a good amount of energy to make and the body focuses on tending towards other more important needs. As long as there is no irritation, redness or undesirable smells, there should be nothing to worry about.

Ready to soak up the sun.
Ready to soak up the sun.

Some Minor Causes

Just as people's' hairs tend to lighten during the summer months, Rover's hairs may bleach slightly too, explains veterinarian Dr. Christian.

Shaving a dog's coat may also cause the hair to become softer and prone to color changes. Generally lighter hues are seen after repeated haircuts.

The fact that clipping affects texture and color of a dog's new coat coming through has caused triggered some groomers to start adding a disclaimer to inform their clients of the possible coat color changes associated with shaving a dog's hair.

Damage to hair follicles from a previous injury may also cause coat color changes in dogs, explains veterinarian Dr. Loretta. In the areas of previous trauma such as a surgical incision site, a clipper burn or even a hot spot, the hair may grow darker in color. This occurs because cells containing melanin, rush to the trauma site as part of the inflammatory process, which turns the skin and hair a darker color, explains Sandy Blackburn in the book: "The Everything Dog Grooming Book."

Hormones Out of Whack

Changes in a dog's coat color and texture can be an indication of hormonal problems. Hypothyroidism, a medical condition where the dog's thyroid levels are low, causes several coat changes and a change in pigmentation may be one of them.

Along with a pigmentation changes, hypothyroidism can cause hair loss, brittle hair, secondary skin infections and other symptoms such as lethargy, obesity and a slower heart rate. It's not a bad idea to have the vet run a comprehensive blood panel to exclude this condition, suggests veterinarian Dr. Scott Nimmo.

A Matter of Stains

dog tear stains

Sometimes dog owners report that the fur on their dog's face is of a different color. This is mostly seen in dogs with candid white coats that attain pink, red or brown colors around the eyes and mouth area. In this case, the colors are really stains that come from the dog's saliva and tears. The cause of these stains on a dog's fur are natural chemicals called porphyrins which arefound in a dog's tears and saliva, explains veterinarianDr. Dave.

Considering that dogs tend to lick several areas of their bodies, it's not surprising for other parts of the body such as feet, legs and sides to assume a brownish tint from the residue of saliva. While the issue may be strictly cosmetic, a veterinarian should be consulted as the staining can be caused at times by underlying medical problems such as blocked tear ducts, in the case of tear stains, or periodontal disease, in the case of mouth stains.

Allergies or skin problems should also be ruled out as these can trigger excessive licking that results in brownish stains on other parts of the dog's body.

Loss of Pigmentation

A case of vitiligo in dog, notice white patches of hair
A case of vitiligo in dog, notice the white patches of hair.

"My dog's coat color has changed drastically and some areas on the face have turned white." Such drastic coat changes may be triggered by a medical condition known as vitiligo. In this case, the loss of pigment mostly affects the dog's nose, lips, and face and it can be temporary or even permanent.

What happens is that, melanocytes, the cells responsible for giving pigment to the dog's coat die or no longer function, explains veterinarian Dr. Gabby. This condition can be caused by an autoimmune disease, genetic factors or a virus, but sometimes its exact causes remain unknown.

Did you know? White isn't really considered a coat color as white hair isn't caused by pigment but rather a lack of pigment.