Scaly Leg and Face Mite Infestations Why They Happen & What To Do Part One

Knemidocoptes mutans is a very successful, microscopic burrowing mite, it is a short-lived arachnid, belonging to the phylum Arthropoda, which also includes insects and crustaceans. Like its relative the spider, it has eight legs although in contrast to the former, it is viviparous, giving birth to live larvae. The major problem with this mite is that in poultry, mainly chickens, game birds and turkeys it causes a condition known as scaly leg and also scaly face. This, although slow to develop, can become disfiguring, cause lameness and lead to necrosis. The mite is slow to develop to infestation proportions but there are specific steps, which can be taken to ensure that you never have to deal with the consequences. As always prevention and a holistic approach is my priority.

Let them eat grass - pasture is high carotenoids, such as beta-carotene, a precursor to Vitamin A

I'd like in this article to look at the correlation between specific deficiency and parasitisation because it is fundamental to everything I believe is wrong with the grain-based diet and the root cause, viz., an unsuitable and insufficient nutrition, of a whole multitude of other conditions and illnesses. Interestingly some meat producers finish pasture-fed animals on a high grain diet so as to drain beta-carotene from the body to transform the typically yellow fat to white!

The Link Between Vitamin A Deficiency and Poultry Parasitisation & Disease

I've mentioned this before in relation to parasites on chickens but here I'm going into much more detail into why it is so important to understand how important Vitamin A is in the diet. Knemidocoptes mutans (portrait left) feeds on keratin, which is the proteinaceous substance that protects the epithelial cells from stress and damage. Epithelial tissue is the sheet of cells which covers the body's surface or lines the body cavities. When we think of this in relation to birds and mites we may consider the β-keratin found in feathers, beaks, scales, claws and skin. Parasites are opportunists and to multiply to infestation level they need a lot of food!

Vitamin A Deficiency and the Over-production of Keratin

Although in the main when we think of Vitamin A deficiency, we may at first think of its effect on sight, with the old adage about carrots and seeing in the dark, it is but a part of the overall importance of this fat soluble vitamin. Vitamin A deficiency has a leading role in the maintenance of the epithelium and it is here that the symptoms of deficiency are most visible.  Although the exact nature of the problem depends on the locations and types of this tissue i.e. a primary build up of keratin or squama (scale), the resulting condition is the same i.e. an excess production of keratin and thus an abundance of mite food. 

Therefore although scaly mite infestation is said to cause other additional problems it is most likely that the Vitamin A deficiency which lies at the root actually engenders them. Take a look at the following symptoms and see what you think:

Vitamin A deficiency symptoms:

  • Soft shelled eggs 
  • rough scaly skin 
  • corns 
  • bumblefoot 
  • poor feather quality  - allowing for debris build up and thus ease of access to mite food
  • weakened embryos and low hatchability
  • dry eyes 
  • swollen third eyelid 
  • swollen face
  • off lay - in particular quail whose ability to lay is said to be directly linked to the amount of Vitamin A stored in the previous year

Further complications can include:

  • sneezing and swollen sinuses due to the blocking of these cavities with excessive squamous and keratin growth.. leading potentially to
  • mucus blockage and thus potential infection, allergy and/or toxicity due to the inability to remove inhaled bacteria, dust and pollutants
  • laboured breathing due to similar blockages in the trachea

Added Consideration - The Importance of Zinc

In cases of any immune system problem, zinc has been found to be beneficial in stimulating immune system response. However, zinc also has a role in the transportation of Vitamin A from storage in the liver for use in the rest of the body.

Stress and its Influence on the Proliferation of Scaly Leg Mite

If you really need a reason not to use something toxic or carcinogenic on the bird's feet and legs to get rid of mites, then this would be it; that you want the bird to clean up the mites after you have helped by softening the affected areas. This is one of the reasons why a bird under stress is more likely to become prone to large colonies of mites because preening is one of the first of the quotidian behaviours that ceases when a bird is under stress. This can be due to physical factors, such as a bird is being picked on so feels unsafe or too harassed to stand still and preen, or a mental perception, due to preening often being observed as a social event; a bullied bird may not feel that it is accepted within the group.

Stress changes the body's metabolism as well as having an effect on the adrenal glands. A bird under stress uses up reserves of nutrients such as Vitamin A and zinc. It may also be unable to replenish these due to the physical inability to get to essential nutrients because it is being blocked or chased. Thus, although you may be feeding or providing forage for an adequate diet,  a stressed bird may be unable to obtain it. At the onset of stress nutrients needed for 'flight' are often at optimal levels or above and those needed for 'rest' are dumped from the system. Therefore, a bird may feel agitated and unable to forage. This adds to the limited intake of foodstuffs and thus a stressed bird will be left with the choice, if that is all that is on offer, of dry, low nutrient grain and nothing else. Dry grain also contains what some refer to as anti-nutrients, such as phytic acid, a way in which the grain protects itself from being consumed, phytic acid actually inhibits the uptake of both vitamins and minerals, thus aggravating the deficiency.

Like most animals stress becomes a vicious circle with nutrient deficiency engendering more stress. With mite build-up, sleep deprivation is an added factor, as the parasite can also interrupt sleep through skin irritation and cause the bird to scratch excessively. Lack of sleep can therefore lead on to further stress.

Tell-tale start of scaly leg - slightly raised scales and white powdery debris


Skin Irritation, Exudates and Lesions from Mite Activity

Knemidocoptes mutans is a burrowing mite, the female burrows down into the keratin of the skin and underneath the scales of the bird to give birth, the nymphs also burrow to create pockets in which to shed their skin. I am not totally clear on whether additional burrows are also due to them gnawing their way through the keratin to consume it. In all I have read, I am not sure if, like their cousins Knemidocoptes pilae, parasites of caged psittacines and in particular budgerigars, the latter exude the enzyme keratinase in order to help them breakdown and absorb the keratin. This enzyme in itself seems to have irritant properties but once the holes are made, there is a possibility that fluid and cells, combined with powdery debris from the mite causes further problems. It is also important to note that if the bird is not preening, is stressed, deficient in nutrient and thus has low immune system function, then there is a possibility for secondary infection from these wounds. It is true that the more the mite creates these lesions and builds up debris the more likely the bird, if untreated, will lose toenails and sadly even toes to this infestation. 

Feathered Feet and Scaly Face

From my observations there is a direct link between birds with feathered feet and the ability of the mite to transfer to the face. This is because the only cases of scaly face I have experienced have been in Cochins, where I've had scaly leg mites remain untreated. This due to the fact the mites have had so many hiding places in and amongst the feather shafts of the feet. Despite the fact that I was painting the oil mix onto individual toes carefully with a brush. In the past I was loath to dip a Cochin's complete foot and leg into an olive and essential oils mix, as I have done with my other smooth-legged birds (i.e. the one and only Bungle left). Now I use a warm water bath with the essential oil 'swished in'.  I realise that without total submersion of the feet, I was allowing some of the mites to escape, reform and more importantly reproduce. However, not all my Cochins get scaly face. Once again it seems to be only those who exhibit stress behaviours and therefore do not forage as much, both factors due to being serial broodies!

Our sweet and patient Pingu, a serial broody Cochin with a recurrence of scaly face

In the next part I will look at the treatment of scaly leg and scaly face, plus the importance of Vitamin D3 synthesis in its prevention.

If you enjoyed this post and found it useful then think about sharing it using the icons below and please feel free to ask questions, comment or share your own experiences of treating your flock.

Thanks for dropping by and all the best,

Illustration of scaly leg mites with thanks to the Pinterest boards of and


Scaly Leg Mite Infestations What To Do Part 2

I look at the options both medicinal and nutritional for dealing with this microscopic mite more

Scaly  Face Mite Infestations Treatment Part 3

If you haven't this miraculous substance already in your pantry then I advise you to get some, both for your own and your poultry's more

Stress - When? Why? Whom? Identification, causes and those most at risk

Stress comes for all sorts of reasons to an organic flock and if not treated within 24 hours, if it's a bad attack, it can be more


Common Poultry Lice  identification, life cycle and major infestation periods

Menacanthus stramineusare ectoparasites, thus living on the skin...with a short life span, which in adult form, is from 2 to 3 weeks read more

Common Poultry Lice - Treatment and Prevention

When you apply any sort of viscous carrier oil to a louse, the spiracles, pores through which it breathes, become blocked, however, read more

Ticks - Identification, life cycle and lifestyle 

I have to say right from the start the more I read about ticks the more confused I get. There is a volume of information floating more

Ticks - Treatment and Removal from a pigeon's face

The idea of using Essential oil of Tea Tree is several-fold in that it has the properties of an anaesthetic, antibacterial, antiviral, antiseptic and more

© 2016 Sue Cross


  1. Looking forward to Part 2... specifically treatment. I suspect I am seeing this manifest as a white flaking skin on combs and faces.

    1. Hi there, I should be writing this up shortly. We have an abundance of chicks and quail at the moment so they are all keeping us pretty busy! All the very best from sunny Normandie, Sue

  2. Thanks for sharing this information on your blog. It is very useful to me. I got good information on your blog.
    vitamin a deficiency symptoms

  3. Hi Sue, woe is me, I have a situation with my quail Tigresse - she's limping, the bad foot and leg hot to the touch and she pecked the tip of a toe raw and bleeding. She also has a bald patch on her tummy. Could this be scaly leg mites? Her scales seem normal to me, but what do I know? It's not bumblefoot and it's not Marek, because she obviously has feeling in her foot, it bothers her so much because she pecked her toe until it bled. This is the dominant hen and a hero layer, started at 8wo
    and laid for two months and a half every day unfailingly (maybe missed once). She continued for the last few weeks, just not every day. Poor thing depleted her body. I'm making liver pate tonight and the birds are gonna get their share of cooked liver. Nobody else has suspected scaly leg mites.
    So what do you think this is? Thank you so much for your time.

    1. Hi Anna I am so sorry that it is only now, a year on, that I finally found your comment. This is because Blogger changed everything about commenting and being advised of comments and I only recently sorted it out and because of that and a comment today, I finally saw yours. I hope you sorted out your quail Tigresse, it does seem like scaly leg - I have a friend in Honduras who had the same and the treatment worked. Until she wrote to me, I had no idea that quail were susceptible to scaly leg but there is no reason why not. I am really sorry because on YouTube and here I always make a point of replying to people asap but Blogger so messed things up with the comment section, it was something to do with the European ruling on privacy so you had to reapply to have notification from your own blog?!? Of course I just ignored it as I presumed it was spam. Hope Tigresse is OK and all the very best from Normandie, Sue

  4. Hi, thanks for your advice, I'm following it with great results so far. Question however: I have one hen with 8 chicks (2 weeks old), I want to treat her too but I'm worried the oil will mess with the babies. Advice appreciated!

    1. Hi there what I would do in the case of a mother hen is to give her a foot bath using water with the essential oils dispersed as well as possible on the top. You do this by swishing the water around and the essential oil will break up and then form into many little 'blobs' on top of the water. You can then dunk the chicken's legs in and out of the foot bath and she will get a good coating on her legs and feet which will go into the skin and then dry off and not get oil over the chicks. I've done this before and it has worked, you just have to keep the chicks busy eating whilst you are giving the mother the treatment and let her legs dry before she sits down with them again. If it's on the face do the same, put the oil in water and swish to break it up and then dab it on with a cotton bud. Interestingly enough the mark of a good essential oil is that it leaves no residue once dry! Hope this helps and all the very best from Normandie, Sue

  5. Legend, thank you. I will try today.