Mange in Dogs: Sarcoptic vs Demodectic — What Every Owner Needs to Know

"Mange" is two completely different diseases sharing one name. Mixing them up leads to wrong treatment — and, in one case, a missed zoonotic risk to your household. Here is the complete picture.

Sarcoptic Mange (Canine Scabies)

What It Is

Infestation by the mite Sarcoptes scabiei var. canis, which burrows into the skin to lay eggs. It causes the most severe itch of any canine skin disease.

Symptoms

• Extreme, relentless itching — often worse at night
• Preferred sites: ear margins, elbows, knees, groin, armpits
• Progressive hair loss from scratching
• Crusting, self-inflicted wounds, thickened darkened skin in chronic cases
• "Elbow sign": tapping the ear margin triggers rapid hind-leg scratching — a classic reflex

Can It Spread to People?

Yes. Sarcoptes scabiei can temporarily affect humans. They develop hives, itching, and red spots — typically on the arms and abdomen. The mites can't reproduce on human skin but cause symptoms until they die (days to weeks). If your dog has sarcoptic mange and family members are itching, consult a dermatologist alongside treating the dog.

Diagnosis

Deep skin scraping examined under a microscope. Results can be falsely negative — if the clinical picture is consistent, treatment is initiated regardless.

Treatment

• Isoxazolines (NexGard, Bravecto, Simparica) — current treatment of choice; highly effective
• Injectable ivermectin (note: contraindicated in Collies and MDR1-mutated breeds)
• Treat ALL animals in the household, even those showing no signs
• Wash all bedding at 60°C — mites don't survive more than 3 days off the host

Demodectic Mange (Demodicosis)

What It Is

Overgrowth of Demodex canis mites, which normally live in small numbers in every dog's hair follicles. Disease occurs only when the immune system can't keep them in check.

Can It Spread to People?

No. Demodex canis is not zoonotic — it poses no risk to humans or to immunocompetent dogs. It's only transmitted from mother to pup in the first days of life.

Forms

• Localised: 1–5 patches of hair loss, minimal itch. Common in puppies. Resolves spontaneously in ~90% of cases.
• Generalised: More than 5 lesions or extensive involvement. Often complicated by secondary bacterial infection. Requires active treatment.

Symptoms

• Patchy hair loss (face, around the eyes, legs)
• Little or no itching — the key distinction from sarcoptic mange
• In severe cases: thickened, malodorous skin with crusting

Treatment

• Localised form in healthy puppies: monitor and wait
• Generalised form or adults: isoxazolines (NexGard, Bravecto, Simparica) — highly effective
• Treat secondary bacterial skin infections with antibiotics

Quick Comparison