Demodectic Mange: The 4 Most Important Questions You Should Ask

by Simon Tong

Demodectic mange is one of the types of skin problems referred to as mange; which affects dogs around the world. The demodectic type may seem like the rather harmless one, but that doesn’t mean that it can be taken lightly – if spotted in older dogs, it could mean the presence of other, more serious conditions below the surface.

What is demodectic mange, exactly?

Demodectic mange, known otherwise as follicular or red mange, is a medical condition that leads to irritation of the skin of a dog, causing it to become inflamed.

The main characteristics of demodectic mange include a development of scaly textures on the skin, as well as hair loss and inflamed skin. 

In more advanced conditions, oozing pus can also be found on the skin, which will harden and eventually produce a crusty texture. The problem areas are usually not itchy, however.

Demodectic mange typically appears in dogs that do not have a fully functioning immune system, such as puppies and dogs that have had their immune systems weakened.

What causes demodectic mange?

This skin condition can be blamed on the presence of the Demodex mite. These little bugs can’t usually be seen with the naked eye, but they strongly resemble tiny cigars with legs when viewed under the microscope.

The Demodex mite can be found in virtually every dog in existence. 

The only reason why they have not caused a ‘mange epidemic’ yet is that these mites aren’t actually very tough; they are easily beaten by the immune systems present in the bodies they live in. As a result, Demodex mites only exist in a tiny amount and are too weak to cause any serious damage.

However, as you may have guessed, that is not true for puppies, old dogs, and dogs that are ill. Their immune systems aren’t working at their usual capacity, which gives the Demodex mites a foot in the door – so to speak – thereby causing all sorts of skin problems.

There are also some very rare cases where the mites have multiplied to such an extent that they can overpower a dog’s defenses, giving them the opportunity to increase their numbers exponentially and causing other complications as a result. In these cases, the dog’s condition is considered severe enough to warrant an emergency visit to the vet. Some dogs may even reach such an advanced stage of demodectic mange that there is no other choice but to be put down by the vet. Granted, such a scenario would be very rare indeed, but it also proves that demodectic mange is not something to be taken lightly.

How do Demodex mites harm dogs?

The Demodex mites make their home in the hair follicles of dogs (thus giving it the alternative name of ‘follicle mange’). The problem starts when the rapid reproduction of mites causes the follicles to become inflamed, thereby causing the hair to fall off. This is why one of the most obvious symptoms of demodectic mange is a drastic loss of fur.

However, hair loss and inflamed skin are not the only things that Demodex mites can cause. If you will recall the part about rare fatal cases briefly discussed above, it shows that the mites are also capable of disrupting the immune system of the dog entirely. When that happens, the dog will be vulnerable to a host of other diseases unrelated to mange, which will complicate things a lot more.

How did my dog get this, anyway? And is it contagious?

Here’s a bit of good news: Demodex mites are not contagious at all. It’s very uncommon for a dog to get it by interactions with other dogs. It’s also impossible for humans to be affected by any interaction with a dog that has demodectic mange, so don’t worry about getting any of those while treating them.

But of course, you may be wondering, ‘How do dogs get this problem, then?’

The answer is that their own mothers were the initial source of the Demodex mites, while they were still puppies.

It’s very possible that when the puppies were very young, perhaps even when they were just out of the womb, some of the mites would already have turned to them as their host of choice. The lack of a functioning immune system in the very early days of a dog’s life may well be the window of opportunity the mites needed to increase their population.

If you think about it for a while, this is actually in line with the fact that older dogs and sick dogs are prone to demodectic mange as well, because their immune systems were also malfunctioning.


Demodectic mange seems to be a rather benign problem; they don’t affect the average adult dog, they get killed by immune systems that work correctly, and they aren’t contagious at all. While it is true that they don’t cause much harm to most dogs, it still doesn’t mean that you should treat demodectic mange lightly.

A severe case of demodectic mange usually means that another health problem is threatening your dog.

Apart from that, they can also cause a lot of trouble with the fur and skin. This can mean a source of misery for you in regards to your dog’s appearance as well as health if it somehow manages to become a major problem.


Simon is the owner of a Miniature Schnauzer, as well as, a website devoted to educating visitors on dog skin problems. Simon started this website after his Schnauzer suffered from a severe skin condition.

 For more information, visit this page to learn more about demodectic mange.