Demodectic Mange in Dogs: Symptoms & Treatment

Demodicosis in dogs is an inflammatory skin condition caused by an overgrowth of microscopic mites that live naturally in a dog’s hair follicles. When a dog’s immune system is unable to keep these mites in check, their numbers can increase rapidly, leading to hair loss, skin lesions, redness, and secondary skin infections. While the symptoms can look alarming, demodicosis is not contagious and is often very manageable with proper veterinary care.

Commonly referred to as demodectic mange or red mange, demodicosis can appear in either a localized or generalized form, with severity ranging from mild cosmetic changes to more widespread illness. It is one of many different types of mange.

Localized Demodicosis in Dogs

Localized demodicosis most commonly occurs in young dogs, typically between three and seven months of age, when their immune systems are still developing. In these cases, dogs usually develop a few small patches of hair loss, often around the face, legs, or trunk.

This form of demodicosis is generally mild and frequently resolves on its own as the puppy’s immune system matures. While many cases require only monitoring, some dogs may experience progression to generalized demodicosis, especially if their immune response does not strengthen as expected.

Generalized Demodicosis in Dogs

Generalized demodicosis is more serious and often affects adult or senior dogs. In these cases, the condition is usually linked to an underlying immune system problem, such as hormonal disorders, chronic illness, cancer, or long-term stress.

Because the mite overgrowth is more extensive, generalized demodicosis can be harder to treat and may require long-term management. Without proper treatment, dogs may develop painful skin infections, widespread hair loss, and systemic illness.

Symptoms of Demodicosis

The symptoms of localized and generalized demodicosis are similar, but generalized cases tend to be more severe and widespread. Signs may include thinning or patchy hair loss, red or inflamed skin, and scaly or crusty areas. Localized cases usually affect the face, legs, or trunk, while generalized demodicosis can involve the entire body, including the feet.

Unlike other types of mange, demodicosis is not always intensely itchy at first. However, itching often becomes more pronounced when secondary bacterial infections develop. In severe cases, dogs may also show lethargy, decreased appetite, fever, or a general decline in overall health.

What Causes Demodicosis in Dogs?

Demodex mites naturally live on nearly all dogs and are a normal part of healthy skin. In most cases, these mites cause no problems at all. Demodicosis occurs when a dog’s immune system fails to regulate mite populations, allowing them to multiply excessively.

This immune imbalance may be temporary, as seen in puppies, or related to chronic disease, poor nutrition, stress, or certain medications in adult dogs. Some breeds are also thought to have a genetic predisposition, which is why dogs with severe or recurring demodicosis are not recommended for breeding.

How Demodicosis Is Diagnosed

Veterinarians diagnose demodicosis through deep skin scrapings, which allow them to examine hair follicles under a microscope for mites. Multiple scrapings may be needed, especially in generalized cases.

Additional testing, such as blood work or hormone screening, may be recommended to identify any underlying conditions contributing to immune suppression. These tests help guide treatment and improve long-term outcomes.

Treatment Options for Demodicosis

Localized demodicosis often requires little more than observation, as many cases resolve without medication. Your veterinarian may still recommend gentle medicated shampoos or topical treatments to support skin healing.

Generalized demodicosis typically requires oral or topical medications designed to eliminate mites. Antibiotics are commonly prescribed when secondary bacterial infections are present. In dogs with immune-related conditions, addressing the underlying disease is essential for successful treatment.

Severe or chronic cases may require long-term therapy, and treatment often continues for several weeks beyond the point when mites are no longer visible to prevent relapse.

Long-Term Care and Monitoring

Dogs with generalized demodicosis need regular veterinary rechecks to ensure treatment is working. These follow-up visits often include repeat skin scrapings and, in some cases, blood tests.

Many dogs with a history of demodicosis remain on preventative flea and tick medications that also help control mites. The dosing schedule depends on the product used and the severity of the disease, but long-term prevention is often part of management for chronic cases.

Preventing Demodicosis Flare-Ups

While demodicosis cannot always be prevented, maintaining your dog’s overall goo health is an important role in reducing the risk. A high-quality diet, routine veterinary care, stress reduction, and prompt treatment of illness all support a strong immune system.

Spaying females may reduce the risk of recurrence, and dogs with chronic generalized demodicosis should not be bred, as susceptibility can be passed on to offspring. Importantly, demodicosis does not spread to other pets or to humans.

When to Call the Vet for Demodicosis

You should contact your veterinarian if you notice patchy hair loss, red or inflamed skin, or scaly areas that do not improve within a couple of weeks, especially in young puppies. While localized demodicosis can resolve on its own, a veterinary exam helps confirm the diagnosis and rule out other skin conditions that may look similar.

A vet visit is especially important if your dog’s hair loss begins to spread rapidly, involves multiple areas of the body, or affects the feet. Swollen paws, sores between the toes, or signs of pain can indicate generalized demodicosis or secondary infection, which requires prompt treatment.

You should also call your veterinarian if your dog develops itching, oozing sores, foul skin odor, fever, lethargy, or a decreased appetite. These symptoms often point to bacterial infections that can worsen quickly without antibiotics.

Adult dogs showing signs of demodicosis should always be evaluated by a veterinarian, as the condition in older dogs is often linked to an underlying immune or hormonal disorder. Early testing can help identify and treat the root cause before the skin disease becomes severe.

Prognosis: Will My Dog Recover?

Most dogs, especially puppies with localized demodicosis, make a full recovery with little to no intervention. Dogs with generalized demodicosis can also do very well, though some may require lifelong management.

With early diagnosis, consistent treatment, and proper follow-up care, many dogs go on to live comfortable, healthy lives despite a history of demodectic mange.