DEMODICOSIS (DOGS)

Demodicoses (demodectic mange) in dogs is a non-contagious skin disease caused by an overpopulation of microscopic, cigar-shaped mites (Demodex canis or Demodex injai) that live naturally inside canine hair follicles. While healthy adult dogs easily control these mites, an overgrowth happens if a dog’s immune system is under-developed, compromised, or genetically predisposed. Unlike Sarcoptic mange, it can not spread to humans or other pets.

Forms and Symptoms

• Localized Demodicosis: Usually appears in puppies under one year old as 1 to 4 small, patchy spots of hair loss (alopecia), mostly around the face, eyes, and front legs. It is typically not itchy unless a secondary infection develops. [
• Generalized Demodicosis: Involves 5 or more patches or large areas of hair loss across the body and paws. The skin turns red ("red mange"), thickens, flakes, and develops deep crusts. [
• Secondary Infection Signs: Severe itching, pus-filled pimples, oozing sores, and a strong odour indicate that bacteria or yeast have infected the damaged skin. 

Primary Causes

• Immature Immune System: Most common in puppies (juvenile-onset, 3 to 18 months old) while their natural defence systems are still growing.
• Adult-Onset Immunosuppression: If demodicosis strikes dogs older than 2 to 4 years, it is usually triggered by a serious underlying illness (like Cushing's disease, diabetes, or cancer) or immune-suppressing drugs.
• Genetics: A genetic defect in immune response can prevent some dogs from keeping the mite population in check.

Diagnosis

Veterinarians diagnose demodicosis by performing deep skin scrapings. They gently squeeze the skin to push the mites out of the hair follicles and scrape until a tiny bit of capillary blood appears. The sample is then placed under a microscope to confirm high numbers of mites or eggs. Trichograms (plucking hairs to look at the roots) are also used.

Veterinary Treatment Options

• Modern Parasiticides: The primary treatment involves oral chewable flea and tick medications belonging to the isoxazoline class (such as NexGard, Bravecto, or Simparica). They have largely replaced older, harsher treatments because they are highly effective and safe.
• Antibiotics and Topical Washes: If secondary bacterial infections are present, veterinarians prescribe oral antibiotics (like cephalexin) alongside medicated, antibacterial shampoos to clean the crusty skin.
• Older Miticides: In complex or non-responsive cases, daily oral ivermectin or weekly prescription amitraz rinses may still be used under strict veterinary monitoring.
• Treating Root Causes: For adult dogs, treating the underlying disease is mandatory to stop the mange from recurring.

⚠️ Warning: Never use dangerous home remedies like used motor oil, which can cause chemical poisoning or death. Additionally, do not give steroids (like prednisone) to a dog with demodex, as they suppress the immune system and make the condition worse.

To help me provide more specific guidance, could you tell me:

• What is the age and breed of your dog?
• Have you noticed hair loss in just a few isolated spots or is it widespread across the body?
• Is your dog scratching intensely, or does the skin look heavily infected?