Hyperpigmentation in Dogs

Hyperpigmentation can be the result of many conditions in your dog. There is a primary and secondary type of hyperpigmentation and the primary type is usually evident by the time your dog is a year old. 

Due to hyperpigmentation being caused by other conditions, it may only be a minor issue compared to larger concerns you may have about your dog. It may appear that he has a skin infection, allergies and other primary conditions.

Hyperpigmentation is when your dog’s skin begins to darken and thicken in areas. Hyperpigmentation is not a disease in and of itself, rather it is a reaction to something else going on with the skin. 

Signs discussed below will be of actual hyperpigmentation, not necessarily the underlying or other conditions your dog may be dealing with. 

• Discoloration – The areas affected may be light brown to black in color
• Skin changes – The impacted area may become velvety, rough, thickened and there may also be hair loss
• Areas prone to hyperpigmentation – The groin, legs and armpits are often impacted and will most likely be where you notice the changes 
• Areas may appear red around the edges – This is due to a bacterial or yeast infection that is secondary to the hyperpigmentation and underlying issues and can spread to other parts of his body 

Types

Primary 

• Rare – Thought to be breed specific
• Typically, only occurs in the Dachshund breed
• Signs are typically present and obvious by the time he is a year old

Secondary

• Very common among all dog breeds
• Obesity (Labrador Retrievers, Pugs, Dachshunds, English Bulldogs, Cairn Terriers, Beagles, Cocker Spaniels, Rottweilers and more)
• Hormonal abnormalities
• Allergies (Labrador Retrievers, German Shepherds, Basset Hounds, Jack Russell Terriers, Lhasa Apsos, Irish Setters, Yorkshire Terriers)
• Contact dermatitis (Border Collies, German Shepherds, Dalmatians, Dobermans, Great Danes, Labradors, Golden Retrievers and Irish Setters)
• Skin infections

The causes of hyperpigmentation vary greatly and are typically signs of larger medical concerns your dog is experiencing. 

• Hypothyroidism – Up to 33% of dogs diagnosed with hypothyroidism showed signs of hyperpigmentation as one of their symptoms
• Systemic Lupus Erythematosus – Some dogs diagnosed with lupus 
• Allergies – If your dog experiences allergies he may also develop hyperpigmented areas on his skin 
• Malassezia –  a yeast infection that often has hyperpigmentation as a symptom
• Demodicosis – caused by a mite and is a lesser known cause of hyperpigmentation 
• Pseudo-Cushing’s Syndrome – Is an endocrine disorder that is common in dogs middle age and older and can have hyperpigmentation as a result

Diagnosis of hyperpigmentation is accomplished by your veterinarian looking for the typical signs of the condition. Your veterinarian will want to perform a full physical exam and history. Gentle scrapings of his skin may be taken to determine any underlying causes such as parasites or infections. If allergies are thought to be the culprit, food trials may be done to attempt to isolate the cause of symptoms. 

No further testing should be necessary to diagnose the actual hyperpigmentation. However, testing may be done to ensure your veterinarian has identified the underlying cause of your dog’s symptoms.

If hyperpigmentation is primary there is no cure. However, when caught early enough the signs can be managed with shampoos and steroid ointments. Other medications can be used as signs increase or get worse. In the event that there are any other infections, those will be treated as well. 

When the diagnosis is secondary hyperpigmentation your dog’s skin will return to normal once the underlying issue is taken care of. It will be important to also treat any bacterial or yeast infections that he has as well as the hyperpigmentation. 

Antibiotics and antifungal medications can be used to treat yeast infections and bacterial infections of your dog’s skin. Medicated shampoos may also be utilized to help your dog’s skin. Treatment is applied 2-3 times a week and the progress may be slow. Relapse of hyperpigmentation will only be high if the underlying cause of the symptom is not taken care of correctly.

As identified above progress can be slow and it can take weeks or months before your dog’s skin appears normal again. Your veterinarian will discuss any need for follow-up appointments for him. Most follow-up will be needed to continue treating the underlying cause of the hyperpigmentation.