Color Dilution Alopecia in Dogs

Color dilution alopecia (CDA) is an inherited skin condition, and is more common in dogs that have been bred for a diluted coat color. For adult dogs with the inherited gene, it is also considered a form of follicular dysplasia. It is more commonly found in dogs with a fawn or blue coat. These two coat colors have been diluted from reds, browns, blacks, and tans.

Alopecia is a disorder that causes complete and permanent hair loss, resulting in a patchy appearance. It affects the hair follicle at the level below your dog’s skin, causing it to self-destruct, making new hair growth impossible. Hypotrichosis can be confused with alopecia, as it is much more common, although this condition results in less than normal hair, and not total loss of hair coat.

Color dilution alopecia (CDA) is an inherited genetic condition that causes patchy hair loss and skin problems, including scaliness, and itchy skin. It can also present recurring bacterial infections. Other than the cosmetic appearance of your dog, his health is not at risk.

• Hair loss - The first sign of color dilution alopecia is hair loss, though this will not appear until the dog is at least six months old and often up to three years of age
• Broken hairs, known as stubble alopecia - This can be scaling skin, papules (swollen bump not producing pus), and pustules (a small blister or pimple producing pus)
• Dry, flaky skin
• Recurring bacterial infections - This will usually be located on your dog’s back and can be identified by infected hair follicles, looking like tiny bumps
• An infection could also bring with it pruritus (severe itching)

Types

Color Dilution Alopecia (CDA) can affect many breeds, although it may affect only certain individual dogs within those breeds. These individual dogs are recognized by the color of their noses, eye rims, and lips. They may be flesh colored, lavender, blue-gray, or blue. Their coat colors can range from taupe, fawn, blue, blue-fawn, or bronze, although they will always be able to be distinguished from their non-diluted counterparts. Breeds commonly affected by this recessive gene condition are:

• Doberman Pinscher
• Salukis
• Chow Chow
• Great Dane
• Standard Poodle
• Irish Setter
• Yorkshire Terrier
• Dachshund
• Italian Greyhound
• Whippet
• Bernese Mountain Dog
• Chihuahua
• Shetland Sheepdog
• Boston Terrier
• Newfoundland
• German Shepherd
• Schipperke

• The most significant cause for color dilution alopecia is inheritance, although dogs that are affected by the recessive gene will be born with a healthy looking coat
• There is some thinking that the amount of dilution in the dog will translate into the severity of the alopecia
• The D-Locus gene controls the vibrancy of your dog’s coat color
• A non-diluted dog will have normal coloring with either a Dd gene, or DD gene 
• Diluted dogs will have a dd gene, evident by your dog’s nose color
• Because dilution is a recessive gene, only dogs carrying the DD gene can be affected, though a dog in possession of the Dd gene will be a carrier
• As the cause for color dilution alopecia is not completely understood, it is thought to occur when fractured hair releases it's formation of coloring which is deadly to the hair follicles

As a pet owner you may notice changes in your dog’s coat. If you see his fur becoming brittle, broken, or rough, call your veterinarian. If your pet has recurring bacterial infections, discuss this with the veterinary team as part of the diagnosis.

The veterinarian may order a trichogram, which is a microscopic evaluation of your dog’s hair, in order to reveal any large grains of melanin or problems in the hair shaft and follicle. A dermatohistopathology test shows the veterinary team whether there are any hair follicles that may be filled with cystic keratin. It also reveals any clumps of melanin that may be hidden in the deepest layer of cells of the epidermis, and in the shaft and follicle of the hair.

If your veterinarian feels it is necessary to order further diagnostic tests or monitoring, she may choose to obtain a skin sample using local anesthetic. The skin will then be sent to a veterinary pathologist to show if there have been any changes in the condition. Your veterinary caregiver  may test for skin mites to ensure this is not the cause for hair loss. In addition, because color dilution alopecia can mimic hormone related hair loss, your veterinarian may test for a healthy functioning thyroid.

There is no cure for color dilution alopecia as it is a genetic predisposition within your dog. Your veterinarian can treat the symptoms related to color dilution alopecia; it is recommended to consult your veterinarian for advice, before attempting any treatments on your own. 

• Shampoos
• Topical ointments
• Moisturizing rinses
• Antibiotics
• Essential fatty acids
• Vitamin A

Shampoos, ointments, and rinses can be used to help relieve the scaly, dry, itchy skin your dog may be suffering from. Antibiotics may be prescribed to treat any bacterial infections that may occur. Remember to always finish the prescribed medication. Do not discontinue medication at the first sign of relief as it can allow the infection to become stronger next time and possibly become antibiotic resistant. 

Some veterinarians may suggest a high dose of essential fatty acids and a vitamin A supplement. Before trying any homeopathic relief, be sure to consult with the veterinary team to make sure there won’t be any adverse effects or contraindications to concurrent therapy.

Managing the scaliness, infections, and dry skin will be key to the recovery of your canine companion. Do not use human hair loss remedies, as they can be harmful to your dog’s health. Products such as Rogaine can be dangerous, resulting in adverse side effects ranging from:

• Weakness
• Lethargy
• Collapse
• Cardiac disease

Color dilution alopecia can be managed and bypassed by not breeding dogs known to have the color dilution; this includes dogs that are not only directly affected by the “dd” gene, but also their littermates and parents.

Color dilution alopecia can be expensive to treat. If you your dog is at risk of developing color dilution alopecia, start searching for pet insurance today. Wag! Wellness lets pet parents compare insurance plans from leading companies like PetPlan and Embrace. Find the “pawfect” plan for your pet in just a few clicks!