The most telling sign of mange in dogs is sudden, intense itching combined with patchy hair loss, especially around the ears, elbows, belly, and chest. But mange actually comes in two very different forms, each with distinct symptoms, and recognizing which type you’re dealing with changes what to expect. Here’s how to spot it and what happens next.
Two Types of Mange Look Very Different
Mange is caused by microscopic mites living on or in your dog’s skin, but the two common types produce symptoms that are easy to tell apart once you know what to look for.
Sarcoptic mange (also called scabies) is the one most people picture. It causes extreme, relentless itching that comes on suddenly. The mites burrow into the skin and trigger an allergic reaction to their waste, which is why the itching is so severe. You’ll notice small red bumps at first, usually on the belly, chest, ears, elbows, and hocks. Because the dog scratches and bites constantly, those bumps quickly turn into thick, yellow-crusted sores. The skin around them becomes red and raw. If it goes untreated, the sores spread across the body, the skin thickens and folds, and the dog can lose significant weight.
Demodectic mange (sometimes called “red mange”) looks and feels completely different. In most cases, the dog barely itches at all. Instead, you’ll see small, well-defined bald patches with reddened, scaly skin, typically around the lips, eyes, and front legs. Localized demodectic mange usually shows up as one to five of these patches and is most common in puppies under six months old. It often resolves on its own. Generalized demodicosis is more serious: the bald, scaly patches spread across the body, the skin becomes oily and dark, and secondary bacterial infections are common.
Signs You Can Check at Home
If you suspect sarcoptic mange, there’s a simple test veterinarians use that you can try yourself. It’s called the pinnal-pedal reflex. Vigorously rub the tip of your dog’s ear flap against the base of the ear for about five seconds. If your dog reflexively kicks their hind leg on the same side (like they’re trying to scratch), it’s a strong indicator of sarcoptic mange. A study in Veterinary Record found this reflex is about 82% sensitive and 94% specific, meaning it catches most cases and rarely gives a false positive. A negative result doesn’t rule mange out, but a positive one is a meaningful clue.
Beyond that reflex, watch for these patterns:
- Location of hair loss: Sarcoptic mange favors the ear edges, elbows, belly, and chest. Demodectic mange favors the face, around the eyes, and the front legs.
- Itch level: If your dog is scratching frantically and can’t stop, sarcoptic mange is far more likely. Demodectic mange causes little to no itching unless a bacterial infection develops.
- Speed of onset: Sarcoptic mange comes on fast. Demodectic mange tends to develop gradually.
- Skin texture: Sarcoptic mange produces thick, crusty, yellow scabs. Demodectic mange produces scaly, sometimes oily skin with darkened patches.
Why Mange Gets Mistaken for Allergies
Sarcoptic mange and environmental allergies can look strikingly similar. Both cause intense itching, redness, and irritated skin. The overlap is close enough that veterinarians sometimes can’t tell them apart on a physical exam alone. One key difference: allergies tend to develop seasonally or after exposure to known triggers, while sarcoptic mange appears suddenly and gets worse fast regardless of environment. The pattern of affected areas also differs. Allergies commonly affect the paws, groin, and armpits, while sarcoptic mange hits the ear margins and elbows early on.
There’s also a tricky scenario called “scabies incognito.” If your dog is regularly bathed and well-groomed, the telltale crusts and scales get washed away, making the mites harder to detect even though the dog is still itching. This is one reason mange can go undiagnosed in otherwise well-cared-for dogs.
How Vets Confirm the Diagnosis
The standard diagnostic tool is a skin scraping. Your vet selects an area at the edge of an active lesion (where mites are most concentrated), clips the hair, and scrapes the skin with a blade deep enough to draw a small amount of blood. The collected material goes onto a microscope slide. The vet examines it at multiple focal planes, looking for whole mites, fragments, or eggs.
This test works well for demodectic mange because the mites live in large numbers within hair follicles. Sarcoptic mites are a different story. They burrow and scatter, making them genuinely hard to find. Multiple scrapings from different areas may come back empty even when the dog clearly has scabies. When that happens and the symptoms are strongly suggestive, most vets will start treatment anyway, a practice known as “trial treatment.” If the dog improves on anti-mite medication, that essentially confirms the diagnosis. Some clinics also offer blood tests that detect antibodies to the mites.
When a Secondary Infection Develops
Mange creates ideal conditions for bacteria and yeast to invade damaged skin. This is especially common in generalized demodectic mange, where the combination of mites and infection (called pyodemodicosis) is the norm rather than the exception. Secondary infections also develop frequently in sarcoptic mange because constant scratching breaks the skin open.
You’ll know a secondary infection has set in when the affected areas start to smell. Infected skin produces a noticeable odor along with discharge of pus or blood. The skin may swell, blister, or develop deep, painful sores with heavy scabbing. In short-haired breeds, you might see raised welts around hair follicles where the hairs stand up unnaturally and pull out easily. These infections need separate treatment alongside the mange itself, typically with antibiotics or antifungal medication.
Can You Catch Mange From Your Dog?
Sarcoptic mange is contagious to humans. If your dog has it, you may develop itchy red bumps on your arms, waist, or other areas that contacted the dog. The good news is that the canine variety of scabies mites can’t complete their life cycle on human skin. The rash and itching are real but temporary, and the infestation resolves on its own once all the dogs in your household are treated. Demodectic mange is not contagious to people or to other dogs in most circumstances.
Sarcoptic mites can survive off a host for two to three days, so bedding, blankets, and shared furniture should be washed during treatment. The mites spread through direct contact or shared resting areas, which is why all dogs in a household need treatment even if only one is showing symptoms.
What Treatment Looks Like
Modern oral flea and tick medications (the chewable tablets many dogs already take monthly) have become the primary treatment for both types of mange. These medications kill mites effectively, and most dogs see significant improvement within a few weeks. For sarcoptic mange, the intense itching often starts to ease within the first week of treatment as the mites die, though the skin itself takes longer to heal. Localized demodectic mange in puppies frequently clears up without any treatment at all, but generalized cases require a longer course of medication and follow-up skin scrapings to confirm the mites are gone.
Dogs with secondary bacterial infections will need those treated simultaneously, and some with severely thickened or damaged skin benefit from medicated baths. Chronic, untreated cases where the skin has thickened and folded take considerably longer to return to normal, which is why catching mange early makes a real difference in recovery time.