Understanding Demodectic Mange in Dogs
Demodectic mange, sometimes called demodicosis or red mange, is a common but often misunderstood skin condition in dogs. This disease is triggered by microscopic mites of the Demodex genus, most notably Demodex canis. While all dogs are exposed to these mites early in life—usually from their mothers during the first days after birth—most never develop symptoms. The trouble starts when a dog's immune system can't keep these mites under control.
What Causes Demodectic Mange?
In healthy dogs, demodex mites quietly coexist as part of the normal skin flora. Problems arise when a dog's immune defenses are immature, suppressed, or otherwise compromised. This allows mite populations to explode, resulting in visible skin disease.
- The condition is not generally contagious between adult dogs or from dogs to humans.
- Puppies typically acquire mites from their mothers within the first week of life.
- Genetic factors play a role; affected dogs and their parents shouldn't be bred again.
Types of Demodectic Mange
This disease isn't one-size-fits-all. There are several forms:
- Localized demodicosis: Small patches of hair loss (alopecia), often on the face, head, or forelimbs. Most common in puppies and usually resolves without treatment.
- Generalized demodicosis: Widespread hair loss, redness, scaling, thickened skin, and possible secondary infections. This form needs veterinary care and more aggressive treatment.
- Demodectic pododermatitis: Restricted to the paws, especially in breeds like Old English Sheepdogs and Shar Peis. It can be stubborn and may require biopsy for diagnosis.
Symptoms: What Does It Look Like?
The signs can vary depending on severity and form:
- Patches of hair loss (typically around eyes, face, legs)
- Redness and inflamed skin
- Scaling, crusts, or thickening of the skin
- Bumps (papules), pustules, nodules
- Mild to moderate itching (may worsen with secondary infections)
- Pain, lethargy, fever in severe cases
- Darker skin (hyperpigmentation)
If you notice these symptoms—especially if your dog is young—it's time for a veterinary visit.
Diagnosis: How Vets Confirm Demodectic Mange
A veterinarian typically diagnoses demodectic mange using deep skin scrapings or plucking hairs from affected areas and examining them under a microscope for Demodex mites. In chronic or hard-to-treat cases (or when lesions are deep), your vet might recommend a biopsy or cytology. Occasionally, fecal tests pick up ingested mites; PCR testing exists but isn't usually needed.
Treatment Options
- If your puppy has localized demodicosis: it often resolves on its own! Sometimes topical treatments or medicated shampoos with benzoyl peroxide help healing and prevent infection.
- If your dog has generalized demodicosis: oral or topical miticides are necessary. Common drugs include those from the isoxazoline class (afoxolaner, fluralaner, sarolaner, lotilaner), milbemycin oxime, moxidectin/imidacloprid combos. Injectable doramectin or oral ivermectin may be used selectively—but some breeds (like Collies) can't tolerate ivermectin due to genetic mutations.
- If secondary bacterial or yeast infections develop: antibiotics or antimicrobial shampoos are added to the regimen.
Treatment continues until two consecutive negative skin scrapings confirm that mites are gone—then it's extended a bit longer for good measure. Skin scrapings are repeated every 2-4 weeks during therapy. Relapses can happen within 3-12 months after stopping treatment if underlying issues persist.
Prevention & Prognosis
- Younger dogs (under 18 months) are most commonly affected; many recover as their immune systems mature.
- If an adult dog develops demodicosis suddenly, it may signal an underlying health problem such as cancer or hormonal disorders like hypothyroidism or Cushing's disease—or immunosuppressive medications could be at fault.
A few key points for prevention and long-term management:
- Avoid breeding affected dogs and their close relatives due to genetic risk factors.
- Supportive care matters: good nutrition, parasite control, stress reduction, regular vaccinations, prompt attention to secondary infections—all help recovery.
Mange vs Other Skin Diseases
Mange isn't always easy to tell apart from other causes of hair loss like allergies, ringworm (fungal infection), or bacterial dermatitis. That's why proper diagnosis by a veterinarian is so important before starting any treatment plan.
The Bottom Line on Demodectic Mange
This condition stems from an internal issue—the immune system's inability to regulate normally harmless mites—not from poor hygiene or contagious exposure. Most young dogs recover well with time and appropriate care; however, persistent cases need ongoing veterinary support and careful monitoring for relapses. If you suspect your dog might have mange, don't delay—early intervention leads to better outcomes for both pets and owners alike!
