Demodex in dogs

Health and Wellbeing

Skin problems are super common in dogs, whether they’ve got a lot of itching, losing their fur, or have developed a nasty rash. Red, sore patches of skin are a common symptom of many skin complaints in pets, including demodex.

Demodectic mange, simply known as “demodex”, is one of two types of mange that can affect dogs. It isn’t as common as other types of mange, but the parasites that cause demodex are extremely common, meaning any dog could develop the condition.

Demodex in dogs

Because any dog can be affected, it’s important for dog owners to understand what demodex in dogs looks like and what you can do to prevent or treat this condition. Or maybe your dog has been diagnosed with demodex, and you just want to find out a bit more about it.

We’ve created this guide to demodex in dogs where you can find out everything you need to know, from what causes it, to symptoms, treatment, and prognosis.

What is demodex in dogs?

Demodex is also known as “red mange” or “demodectic mange”. It’s a common skin condition which can affect dogs of any age or breed. It often results in small lesions on your dog’s body, which are patches of hairless, red, sore skin.

What causes demodex in dogs?

Demodex is caused by a specific type of parasitic mite called Demodex Canis and Demodex Injai.

However, D. Injai is far less common. Almost all cases of demodex are caused by Demodex Canis, which are mites that naturally live on all dogs inside their skin and hair follicles.

There is a third kind of demodex mite that can affect dogs which is called Demodex Cornei, but it’s just a variant of D. Canis and there’s very little difference between the two bugs.

All dogs will have some demodex mites living in or under their skin throughout their lifetime. (Even us humans have our own demodex mites that live in our skin all our lives!)

Your dog will first get these mites as a puppy, as the mites on the mother dog will crawl onto her puppies while they’re suckling. It’s thought that all puppies will contract demodex mites within the first 72 hours of their life.

Usually, these microscopic mites don’t cause your dog any harm, and you’d never even notice they were ever there. They live in or under your dog’s skin and come out to eat their dead skin cells.

Usually, a healthy adult dog’s immune system is strong enough to protect a dog from any infection the mites might cause. Their immune system will also effectively control the mite population, so a healthy dog shouldn’t become infested.

However, if a dog has an underdeveloped or weakened immune system, the mites can multiply rapidly and start to cause problems.

Puppies and older dogs have weaker immune systems due to their age. But if an adult dog develops demodectic mange, there is likely an underlying deficiency or illness which has weakened their immune system, allowing the mites to multiply and for demodex to develop.

Types of demodex in dogs

Demodex is divided into types according to what areas of the body are affected, and the age of the affected dog.

Juvenile onset demodex is seen in puppies, and occurs before a dog is 1 year old. This type of demodex is often harmless and most cases go away on their own, or with minimal topical treatment.

Meanwhile, adult onset demodex occurs in dogs who are older than 2 years old.

As well as juvenile onset demodex and adult onset demodex, you can have either localised or general demodex.

If your dog has a case of demodectic mange but it only affects one small area of their body, this is known as localised demodex. A dog with localised demodex will have 4 or fewer lesions on their skin, and their lesion will be no bigger than 2.5cm.

Meanwhile, generalised demodex is diagnosed when a dog has more than 4 lesions on their body, any of the lesions are larger than 2.5cm, or if their feet are affected. In other words, generalised demodex affects a dog’s body.

Is demodex contagious?

Demodex isn’t contagious, but the demodectic mites which cause demodex are.

Demodex mites can’t fly, so their spread is limited, but they can crawl between dogs who are in close physical contact with one another. However, almost every single dog will already have demodex mites, as they crawl from the mother dog to her puppies within hours of them being born. So the mites can spread between dogs, but your dog will probably have them anyway.

Demodex is not contagious to humans. And although cats can develop demodex, the mites which cause their illness are different to the types found on dogs. So your cat shouldn’t be able to catch demodex from your dog, and vice versa.

So ultimately, demodex isn’t contagious once your dog has mites.

Are some dogs more likely to get demodex?

Young dogs are more likely to develop demodectic mange because their immune system is still developing, making it less likely to prevent infection or control mite numbers. Puppies are often diagnosed with demodex between 12 and 18 months of age, but younger puppies can be affected.

Old dogs are also vulnerable to demodex because their immune system will weaken with age. They could also have an age-related illness which impacts their immune system.

Most healthy, adult dogs are pretty safe from demodex. However, any pooch with an underlying health issue or dogs that requires immunosuppressant medication will be at greater risk of developing the disease.

In addition, short-haired dogs are more likely to suffer from demodex than long-haired dogs. And some breeds are considered more likely to get demodex, including Staffordshire Bull Terriers, Staffy crossbreeds, and Shar-Peis. However, any dog of any breed or age can develop demodex.

Signs and symptoms of demodex in dogs

Usually, symptoms of demodex such as hair loss and scabby skin is concentrated around a dog’s eyes and paws. It may be “localised” and only present on one part of their body.

However, in severe cases, your dog might suffer patches of hair loss or scaly skin all over their body which is known as “generalised” demodex.

Symptoms of demodex in dogs include:

  • Hair loss
  • Scabs
  • Dry, scaly skin
  • Red, crusty skin
  • Greasy fur
  • Greasy skin
  • Itching
  • Hyperpigmentation (Blue/grey patches of skin)
  • Pustules

Itching is not a symptom associated with demodex itself, but with secondary skin infection.

The hair loss caused by demodex can be really small, and might look like little more than a scratch on your dog’s skin. However, some dogs will develop obvious bald patches, dry, red skin, and rashes.

Pustules are only seen in severe cases of demodex, and are usually a symptom of secondary infection such as pyoderma.

If your dog is showing any signs of discomfort or symptoms of a skin condition, you should take them to the vet for an examination.

How can demodex in dogs be prevented?

There’s no effective way to prevent demodex in dogs because all dogs carry demodex mites.

However, you can take steps to reduce your dog’s risk of illness or infection which could weaken their immune system, which is when demodex would develop.

Firstly, you should feed your dog a healthy and balanced diet. A complete dog food will provide all the nutrients your dog needs in the right quantities to stay healthy, so they won’t develop nutritional deficiencies which can weaken their immune system.

Secondly, you should provide your dog with regular worming and antiparasitic treatments. This won’t kill the mites on your dog, but it will prevent illness or infection caused by other parasites which can weaken your dog’s immune system.

Finally, making sure your dog is up to date on their vaccinations is another great way to protect their health as it will effectively prevent a number of serious viruses, like parvovirus or distemper. A virus or illness such as these can impact your dog’s immune system, making them more vulnerable to other infections.

Diagnosing demodex

There are many different skin conditions which can affect dogs, and many of them have similar symptoms. For example, patches of hair loss can also be a sign of pyoderma, eczema, ringworm, or even a nutritional deficiency. Your vet will need to thoroughly examine your dog to rule out any other illness as well as testing for demodex.

First your vet will discuss your dog’s lifestyle and symptoms with you, and they will perform a physical examination of your dog. If they suspect demodex is the cause of your dog’s hair loss, they will take a harmless skin scraping to test for mites.

Your vet will take this sample by finding a loose fold of skin on your dog and gently scraping it with a scalpel to remove some skin particles. They will examine these particles under a microscope to assess whether or not there are any surface parasites on your dog that are causing their illness, including the Demodex Cani mites which cause demodex.

If they see mites in the sample, they can usually confirm your dog has demodex. This is because although most adult dogs have demodex mites living on them, they don’t show up in samples unless a dog is infested and demodex is present.

Skin scrapings are also useful in identifying other parasites and infections, such as scabies, harvest mites, or a fungal infection.

Your vet might also take a tape sample. This is where they put some sticky tape on your dog’s skin and pull it off, which will remove some skin particles they can examine under the microscope.

Shar-Peis and other wrinkly dog breeds sometimes require a skin biopsy rather than a skin-scraping due to their deep wrinkles and heavy rolls. Your vet might also take a skin biopsy from your dog if they believe your dog has demodex, but have been unable to find mites in the superficial skin samples taken by tape samples or skin scrapings.

Your vet might want to perform a few other tests to rule out any other parasites or infections that could be causing your dog’s illness. This might include plucking a few strands of fur to examine under a microscope, or a blood test.

How will demodex in dogs be treated?

Treatment for demodex often takes a few weeks. And although demodex isn’t life-threatening, providing proper treatment for your dog is still important to improve their wellbeing and quality of life, and to prevent secondary infection.

Some dogs might suffer future flare-ups of demodex, which will require a longer course of treatment or repeated treatment to manage.

That being said, some cases of localised demodex in puppies or young dogs (<1 year old) do not require treatment and resolve on their own. In fact, around 90% of cases of demodex in dogs under 6 months old will resolve spontaneously.

This is because the puppy’s immune system will strengthen as they grow up, and become able to fight infection and control the demodectic mites. Puppies with generalised demodex affecting their whole body will still require some treatment to help limit the mite numbers, aid the recovery of their skin, and prevent secondary infection.

If an older dog is suffering from demodex, treatment is much more important to prevent the mange from spreading across their body, to prevent secondary infection, and to speed up their recovery. Previously, generalised and adult onset demodex in dogs was tricky to treat, but new medications have been developed which have proven extremely effective.

There are various possible treatments for demodex in dogs, from shampoos, to spot-ons, topical ointments, to tablets. All forms of treatment are effective against all three of the types of demodex mites in dogs.

Common treatment for demodex in dogs includes:

  • Oral treatments
  • Topical ointments
  • Dips
  • Antibiotics (for secondary infections.)

Regardless of what kind of treatment your dog receives, they will need routine visits to the vet to monitor their progress and to assess how effective their treatment is. This usually involves a visit once a month for a physical examination and a skin scraping.

Tablets

A number of new oral medications have been created to treat demodex in dogs, and all have proven highly effective at decreasing mite numbers, reducing lesions, and allowing hair regrowth.

As an example of their success, one small study found that a single dose of Bravecto was highly effective at treating generalised demodex, and no mites were detectable after 58 and 84 days after treatment, and treated dogs had less lesions and hair regrowth after 12 weeks.

Meanwhile, a single dose of Fluralaner saw a 98.9% reduction in mites within 28 days of treatment. A new medicine Sarolaner is also highly effective, with a reduction of 99.8% of mites after one dose, and a 100% reduction after a second dose.

As you can see, oral treatment for demodex in dogs is highly effective because it works from the inside out, so every inch of their skin receives medication. And unlike topical treatments such as shampoos and dips, oral treatment for demodex in dogs is highly effective against generalised and adult onset demodex.

The necessary doses vary between daily tablets, or one tablet every 28 days.

As well as tablets aimed at treating demodex, your vet might prescribe your pooch some antibiotics to help prevent and treat any secondary infection they develop.

Topical ointments and spot-ons

Topical ointments are often given to dogs to help soothe their sore skin and to promote recovery. Some ointments may contain antibiotics too, to fight off any secondary skin infections your dog might have.

Another new topical treatment for demodex in dogs is a spot-on treatment, often containing the same active ingredients as oral treatments. These spot-ons aren’t quite as effective as oral medicines, but they still work well at reducing mites and treating demodex.

Dips and shampoo for demodex in dogs

Shampoos, dips, and topical treatments have been the traditional method of treating demodex in dogs for a long time.

There are shampoos available that can help to kill mites and treat demodex. These shampoos contain benzoyl peroxide and will be prescribed by your vet, but they are usually only given to dogs suffering from localised demodex.

In most cases, you will be advised to bathe your dog more regularly with a gentle shampoo, and then apply a special dip to treat their mange.

These dips are a topical treatment for demodex in dogs and usually contain the insecticide amitraz, which kills demodex mites. Dips are an effective way to treat demodex, but are not as effective at treating adult onset generalised demodex compared to oral treatments.

To use a dip, you must wash and dry your dog, then make a solution of the medicine and water and pour it all over your dog until they are wet all over, then let it air dry. You’ll usually need to do this once a week or once a fortnight, and apply a dip 3 to 6 times over the course of your dog’s treatment.

If your dog has medium or long fur, their fur will need to be clipped all over before receiving a dip to treat their demodex.

Natural treatments for demodex in dogs

There are no natural treatments that cure demodex in dogs, but there are plenty of things you can do at home to help your pooch to recover from demodex, or to lower their risk of demodex in the first place.

Natural treatments for demodex are supportive. This means they can help to aid recovery and make your dog feel more comfortable, but they can’t tackle the cause of demodex and won’t cure their illness on their own.

Feeding your dog a balanced and highly-nutritious diet is vital for keeping your dog healthy, and supporting their immune system to prevent illness. The right nutrition will help them to heal too. A healthy dog food should provide all the nutrients your pooch needs to support a strong immune system, as well as to encourage healthy skin and fur growth.

Extra omega-3 fatty acids are another natural way to improve your dog’s skin condition because they have powerful anti-inflammatory properties which can help to reduce swelling and redness, and soothe your dog’s sore skin. Fatty acids can also strengthen the skin’s barrier, helping to prevent infection. You can find fatty acids in whole meat and in fish.

Giving your dog a bit of yoghurt might also help to improve their skin and heal lesions caused by demodex. It won’t cure their condition, but it is a safe and healthy treat that could help your dog feel more comfortable.

Outlook

The prognosis for puppies and young dogs with demodex is generally very good. They usually respond well to treatment for demodectic mange, and after the initial treatment they will make a full recovery.

However, demodex in older dogs is more of a cause for concern. This is because an adult dog should have a functioning immune system which effectively manages the effects of mites and prevents mange. So, if an adult dog develops demodex, there is something going on inside them that is weakening their immune system.

The cause of your dog’s impacted immune system must be found and treated, sometimes before they can be treated for demodex. Your dog’s immune system could be impacted by anything from a virus such as distemper, the presence of other parasites, nutritional deficiencies, or conditions such as hypothyroidism or even cancer.

How well your dog recovers will depend on what has compromised their immune system and how well they respond to treatment for that condition. Many dogs with an underlying condition take longer to recover from demodex. They might also suffer from future flare-ups of demodex, but these should go away with repeated treatment.

Demodex in dogs shouldn’t be a serious illness, and certainly not life-limiting. Although if it is left untreated, it can lead to more acute cases of mange and severe secondary infection. Not to mention, your poor pooch will be very sore and uncomfortable!

Dr Andrew Miller BVSc MRCVS

Written by: Dr Andrew Miller MRCVS

Andy graduated from Bristol University in 2010 and sees nutrition as a foundation for our pet's wellbeing and takes a common-sense approach. We are what we eat, and it shouldn't be any different for our pets.