Mange in Dogs: Sarcoptic vs Demodectic Explained

Mange in dogs is caused by two very different mites, and telling them apart matters. Sarcoptic mange (often called canine scabies) burrows under the skin, is highly contagious between dogs, and causes ferocious, sudden itching. Demodectic mange lives inside hair follicles, is not normally contagious at all, and tends to show up when a puppy’s immune system is still maturing, or an adult dog’s is under strain.

Both types need a vet to confirm what you’re dealing with, usually with a skin scrape, because the two can look similar on the surface but are treated very differently. This guide, researched from UK and international vet sources, covers what each type looks like, how vets diagnose and treat them, and whether you or your family are at any risk.

What is mange, exactly?

Mange is not one single disease. It’s a general term for skin disease caused by microscopic mites, and in dogs it comes from two mites with different habits, treatments and outlooks, according to VCA Animal Hospitals:

• Sarcoptic mange is caused by Sarcoptes scabiei, a mite that burrows just beneath the surface of the skin.
• Demodectic mange is caused by Demodex canis, a mite that lives inside hair follicles and, in tiny numbers, on almost every dog’s skin without causing any problems at all.

Not every itch is mange, of course. Yeast overgrowth, allergies and other itchy skin conditions like Malassezia dermatitis can look similar from the outside, which is exactly why a vet check matters rather than guessing from a photo.

Sarcoptic vs demodectic mange: what’s the difference?

What are the signs of mange in dogs?

Sarcoptic mange tends to announce itself fast. Dogs develop intense itching that comes on suddenly, according to the MSD Merck Veterinary Manual, and it typically starts on thinner-skinned areas such as the ears, elbows and hocks before spreading, per PDSA. As the scratching continues, small bumps can turn into crusty sores, with hair loss developing, per Blue Cross, and as the condition progresses the skin can become thickened and darkened too, per VCA. Left untreated, nearby lymph nodes can swell too.

Demodectic mange looks and behaves quite differently. It usually causes patchy hair loss with little or no itching, unless a secondary infection sets in, per VCA. The localised form is the one most owners meet: one to five small, bald, scaly patches, often on a puppy’s face or front legs. The generalised form spreads much further across the body and is a more serious disease that needs proper veterinary treatment rather than a wait-and-see approach.

How do vets diagnose mange?

Mites are one of several causes of a persistently itchy dog. Our guide to itchy skin in dogs sets out how the causes differ, and there is a companion piece for when you cannot find any fleas.

A vet will usually take a skin scraping and examine it under a microscope for both types, but the two mites behave very differently once there. For demodectic mange, the mites are typically found this way and confirm the diagnosis directly, per VCA. Sarcoptic mange is the opposite story: because the mites burrow deep, and it only takes a handful to cause severe itching, it’s genuinely common for a scrape to come back clear even in a dog that does have sarcoptic mange, according to both Blue Cross and VCA.

Sarcoptic mange is highly contagious to other dogs and humans.

Verified sourceVCA Animal Hospitals · read the source →

That’s why many vets are willing to treat on the basis of symptoms alone if a dog’s itch fails to respond to anything else. A clear skin scrape does not rule sarcoptic mange out.

Can I catch mange from my dog?

This is usually the first question worried owners ask, and the answer depends entirely on which type your dog has.

Demodectic mange is not contagious to people or other pets. It passes from a mother dog to her puppies in the first few days of life, and already exists in small, harmless numbers on almost every dog’s skin, according to Blue Cross and VCA.

Sarcoptic mange is different: it’s zoonotic, meaning it can spread from dogs to people. That doesn’t mean you’ll develop ongoing canine scabies, though. Because the mites cannot complete their life cycle on human skin, an infection in a person is temporary, usually dying out within a few days, though it can leave you with an itchy rash while it lasts, according to PDSA and Blue Cross; VCA notes the itching can be intense until the mites die off. If anyone in your household develops an itchy rash while your dog is being treated for sarcoptic mange, VCA advises contacting your GP promptly and mentioning the possible exposure.

How is mange treated?

Every case of mange needs veterinary guidance; there is no reliable home cure for either type, and treating the wrong thing can waste weeks while symptoms get worse. For sarcoptic mange, vets typically prescribe a spot-on, tablet or medicated shampoo to kill the mites, and dogs often need two or three rounds a few weeks apart to make sure every mite is gone, per PDSA. Every other dog in close, regular contact usually needs treating too, since sarcoptic mange spreads so readily between them, and bedding should be washed thoroughly to stop reinfection, per VCA.

Demodectic mange is treated differently depending on how widespread it is. Localised patches in puppies often resolve by themselves as the immune system matures, with a vet monitoring progress along the way; Blue Cross notes that in up to half of generalised cases in young dogs, the immune system eventually recovers and suppresses the mites on its own. Generalised demodicosis in any dog is treated as a more serious disease, needing a longer course of vet-prescribed anti-parasite treatment, sometimes alongside antibiotics or medicated washes for any secondary infection, and can take a long time to fully clear, per VCA.

While you’re waiting on a diagnosis, keep an eye on any broken or infected skin from all the scratching. Problems like hot spots can develop on top of mange and complicate the picture, so don’t be surprised if your vet ends up treating more than one thing at once.

If you’re trying to work out whether ongoing scratching, redness or hair loss is mange or something else entirely, our dog skin, paw and nose care hub is a good next stop for the wider picture of what’s normal and what needs a vet.

Because several dog skin problems look alike from the outside, it is worth knowing how this compares to ringworm and flea allergy dermatitis, which can cause similar signs. When in doubt, a vet check settles it.