Demodectic Mange in Dogs: Symptoms, Diagnosis & Care

What is Demodectic Mange?

Demodectic mange is a parasitic skin condition primarily caused by the Demodex canis mite. These microscopic mites naturally inhabit the hair follicles and oil glands of most healthy dogs, typically without causing problems. However, when a dog's immune system is immature or weakened, such as in puppies or older dogs with underlying health issues, these mites can multiply excessively, leading to skin disease known as demodicosis or red mange.

This condition is not contagious in the usual sense; mites are generally transferred only from mother to puppy shortly after birth. Most cases arise due to immune system imbalance rather than direct transmission between adult dogs.

What Causes Demodectic Mange?

All dogs carry small numbers of Demodex mites, but problems occur when the immune system cannot keep their populations in check. Causes include:

• Immature immunity in puppies under 12-18 months
• Age-related immune decline or illnesses in older dogs
• Use of immune-suppressing medications like corticosteroids
• Genetic predisposition in some breeds

Dogs Most at Risk

Puppies with vulnerable or immature immune systems are most commonly affected. Adult dogs with compromised immunity—whether due to disease, medication, or age—are also at risk. This is called "adult-onset demodicosis." Prompt veterinary attention is important for all suspected cases to diagnose and manage the underlying immune status.

Recognising Symptoms

The signs of demodectic mange can range from mild to severe and include:

• Hair loss or thinning, especially around the face, eyes, muzzle, head, chest, and forelimbs initially
• Red, inflamed, and crusty skin lesions
• A greasy or moist skin texture
• Itching, which may vary in intensity
• Secondary bacterial infections, which may cause lethargy, fever, and loss of appetite

Localized mange features fewer than five patches and sometimes resolves without intensive treatment in young puppies, while generalized cases affect larger skin areas, often requiring a more comprehensive approach.

How is Demodectic Mange Diagnosed?

Diagnosis is made by a vet through:

• Deep skin scrapings examined microscopically to identify mites within hair follicles and oil glands
• Hair plucking or biopsies in uncertain cases
• Screening for secondary infections or other underlying health conditions

Because the mites live deep beneath the skin surface, samples must be taken carefully and examined under a microscope for definitive diagnosis. Additional tests may be necessary to evaluate overall immune health.

Treatment Options

Treatment depends on the severity of the infestation and immune competency of the dog. Many cases in young puppies may resolve spontaneously as immunity develops. For others, veterinary-prescribed treatments are essential and may include:

• Clipping hair from affected areas to improve topical medication efficacy
• Topical treatments: Shampoos containing amitraz (e.g., Aludex) applied repeatedly at intervals; care must be taken to follow safety precautions as some pets may react adversely.
• Systemic treatments: Ivermectin or related oral medications under veterinary guidance (contraindicated in Collies and similar breeds)
• Antibiotics if secondary bacterial infection is present

Monitoring during treatment is crucial to detect any adverse effects early and ensure a full recovery.

Nutritional Support for Skin Health

While demodectic mange is not directly caused by poor nutrition, maintaining a balanced diet supports immune function and skin repair. Key nutrients beneficial for skin and coat health include:

Protein

Provides building blocks for hair and skin cell repair. High-quality, digestible protein from sources like eggs, fish, poultry, and lamb is recommended.

Fats

Essential fatty acids, particularly omega-6 linoleic acid and omega-3 fatty acids (DHA and EPA), help maintain healthy cell membranes and have anti-inflammatory properties. Fish oils are excellent natural sources.

Vitamins

• Vitamin C: Essential antioxidant important for collagen synthesis and tissue health.
• Vitamin E: Protects skin cell membranes and promotes healing; found especially in oily fish.

B Vitamins and Minerals

• Biotin: Supports metabolism of amino and fatty acids, vital for skin and coat.
• Riboflavin (Vitamin B2): Involved in production of healthy hair, skin, and nails.
• Copper: Important for collagen synthesis and skin elasticity.
• Selenium: Boosts immune response by stimulating infection-fighting cells.
• Zinc: Crucial for enzyme functions and wound healing.

Incorporating these nutrients through balanced commercial diets or supplements, after veterinary advice, can provide beneficial support during mange recovery.

Conclusion

Demodectic mange is a challenging but manageable condition in dogs primarily related to immune system function. Early veterinary diagnosis and appropriate treatment are vital to prevent complications such as secondary infections or generalised skin disease. Supporting your dog’s immune health through good nutrition and attentive care can improve outcomes and help your pet return to comfortable, healthy skin.