What Is Demodectic Mange in Dogs?
Demodectic mange in dogs is a skin condition caused by an overgrowth of Demodex canis, a mite that naturally resides in canine hair follicles. When a dog’s immune system becomes compromised, these mites can multiply excessively, leading to skin lesions.
Factors Promoting Demodex Proliferation
Several factors can contribute to the overpopulation of Demodex mites:
- Genetic predisposition
- Immune system disorders (e.g., stress, malnutrition, immunosuppressive therapies, internal parasites)
Forms of Demodectic Mange
Demodectic mange manifests in two primary forms:
Localized Form
Typically seen in puppies aged 3 to 6 months, this form presents as red, hairless patches, mainly around the eyes and forelimbs. Itching is uncommon unless a secondary infection occurs. This form often resolves without treatment.
Generalized Form
More severe, it can be juvenile (between 3 and 18 months) or adult-onset. Lesions are widespread, and the skin becomes thickened, pigmented, and seborrheic. Pustules may develop due to secondary bacterial infections. Adult-onset cases may indicate an underlying systemic disease and require further evaluation.
Transmission
Transmission primarily occurs through direct contact, especially between a mother and her puppies during the first days of life. Demodex is not contagious among adult dogs. Certain breeds are more predisposed, including:
- Shar-Pei
- West Highland White Terrier
- Scottish Terrier
- Bulldog
- Boston Terrier
- Great Dane
- Airedale
- Afghan
- Malamute
Diagnosis
Diagnosis involves a deep skin scraping to identify adult Demodex mites, larvae, or eggs. In some cases, a skin biopsy may be necessary to confirm the presence of the parasite.
Treatment
Treatment focuses on addressing the underlying cause of the infestation. Affected areas should be:
- Shaved
- Cleaned with an antibacterial shampoo
If a secondary bacterial infection is present, antibiotics may be prescribed. For generalized demodicosis, specific antiparasitic medications are used, such as:
- Fluralaner (e.g., Bravecto)
- Afoxolaner (e.g., NexGard)
- Lotilaner (e.g., Credelio)
Treatment continues until skin scrapings confirm the eradication of mites, which may take up to a month after symptoms resolve.
