How to Tell If Your Dog Has Demodex Mites
Understanding demodex mites and their impact on your dog’s health is crucial. These microscopic parasites live in hair follicles and are a natural part of your dog's skin flora. However, when a dog’s immune system is underdeveloped or compromised, these mites can proliferate and cause a skin condition known as demodectic mange or demodicosis.
What Are Demodex Mites?
Demodex mites, especially Demodex canis, are tiny, cigar-shaped ectoparasites found in canine hair follicles. Puppies typically pick them up from their mother shortly after birth. In most dogs, a healthy immune system keeps the mite population in check.
Types of Demodectic Mange
- Localized Demodicosis: Characterized by small, isolated patches of hair loss, commonly around the face and forelimbs. It often resolves on its own, especially in puppies.
- Generalized Demodicosis: A more serious, widespread condition with significant hair loss, inflamed skin, and potential for secondary infections. Requires veterinary treatment.
- Demodectic Pododermatitis: Affects only the paws, particularly in breeds like Shar Peis and Old English Sheepdogs. It may need a biopsy for accurate diagnosis.
Symptoms of Demodex Infestation
Common signs that your dog may suffer from demodex-related mange include:
- Patches of hair loss (alopecia), especially on the face and legs
- Red, inflamed, or thickened skin
- Scaling or crust formation
- Swelling, pustules, or nodules
- Hyperpigmentation (darkened skin)
- Itching, especially with secondary infections
- Lethargy, fever, or draining wounds in severe cases
How is Demodex Diagnosed?
A veterinarian will typically perform one or more of the following:
- Deep skin scraping to find mites under a microscope
- Hair plucking for microscopic examination
- Skin biopsy or cytology for chronic or unresponsive cases
- Occasionally, fecal flotation or PCR testing, though less common
Treatment Options
Based on the type and severity of the mange, therapies include:
- Topical treatments for localized demodicosis—may include shampoos with benzoyl peroxide
- Oral/topical miticides, such as isoxazoline (e.g., afoxolaner, fluralaner, sarolaner), milbemycin oxime, or moxidectin+
- Injectable or oral ivermectin (not suitable for dogs with MDR1 mutation)
- Antibiotics or antifungals for secondary bacterial or yeast infections
Treatment continues until at least two consecutive negative skin scrapings have been achieved, usually with ongoing monitoring every 2–4 weeks.
Prognosis and Prevention
- Young dogs often recover as their immune systems mature
- Adult-onset demodicosis may signal an underlying disease
- Prevent breeding from affected dogs and their relatives to avoid genetic passing
- Supportive care: good nutrition, stress management, parasite control, and vaccines
- Relapses may occur but are manageable with proper veterinary care
When to See a Vet
If your dog exhibits symptoms of mange or has unexplained hair loss and skin irritation, schedule a veterinary visit for a full evaluation. Early diagnosis and treatment can prevent escalation and secondary infections.
Remember, demodectic mange is not contagious to other pets or humans in normal cases, differing significantly from sarcoptic mange, which is highly contagious and zoonotic.
