Thursday, October 31, 2013

Demodex, The Bug That Digs Deep.

Few diseases in veterinary medicine have the ability to conjure up sympathy and open wallets faster than Demodex does. 

A Demodex dog typically has huge areas of exposed, dry, leathery skin often with a few scarce patches of islands of dull hair. These dogs are pitiful to look at, heartbreaking to see, and conjure feelings of desperation and despair.

For the young juvenile Demodex dogs I see it is often a simple fix that includes;
  • Proper nutrition.
  • Proper housing.
  • Proper veterinary care.
  • Spaying/neutering.
With these few simple steps most of the juvenile Demodex dogs will look like a million bucks in a few months. I know it sounds non-sensical but if you are walking through the pound and you see a small sad bald puppy I would encourage you to try to look past the pathetic exterior. Don't walk by them and choose the "NO" box because they look like they are going to cost you a fortune. Adopt your pet based on their personality and how they will integrate into your household, and not whether the face seen in the reflection of the mirror on the wall would answer "You, my dear," back at them.

Think I'm wrong? Well, let me tempt your doubt. Almost every single juvenile Demodex pup will be a pit bull. Why? Well, in my part of the world they are horribly over bred by people who can't even begin to take care of their most basic needs. So they end up dumped at a shelter. You add the stress of being placed there, to malnutrition, intestinal worms, and unspayed/neutered and 'poof' you get the unmasking of Demodex.

But under that neglected pigskin exterior you will often find a sweet, gentle, love bug simply waiting to be uncovered. They may look awful initially, but remember beauty is only skin deep. A little exfoliation, medication, and TLC and you will find your own miracle.

Here are some important points to remember about Demodex. 
Demodex is a type of mange. 

Simplified mange mites come in two forms: 
  1. The deep (Demodex) dwelling mange mite, and,
  2. The superficial (scabies) dwelling, itchy ones. 

Demodex; In a nut shell;
  • Causes severe and progressive hair loss.
  • These critters live deep in the hair follicle. So as they chew away in the hair shaft the hair starts to fall out.
  • Is most often seen in very young OR older dogs.
  • There is usually something else going on if you see Demodex. Go look for it, and treat for both.

Scabies (Sarcoptes scabei);
  • Is itchy!
  • Can affect multiple dogs.
  • Can be confused more easily as a normal skin infection.
  • Diagnose by response to treatment or superficial skin scrape (but beware these buggers are hard to find, so I treat if I suspect them anyway).
  • You can swap this little critter with your pet, so if everyone is itching tell you Dr and DVM.
Why do I think that Demodex is an easy win-win?

Well, because Demodex is a natural resident of the skin. In normal healthy dogs the Demodex is kept at bay by the healthy immune system. Rock the boat to hard (or have an unhealthy immune system because of stress, hormones, poor diet, etc.), and those little resident once-before harmless bugs start to take over.

Demodex is usually fairly easy to diagnose. Does your dog look mangey? If so, do a skin scrape and look under the microscope. See a bunch of Michelin men looking worms waving their many arms at you? Then, there you have it, you have Demodex.

Age determines whether or not the Demodex is juvenile (less than one year old), or adult onset. Demodex is further classified as localized or generalized. My usual advice for a puppy (juvenile form) is if the lesions are localized (I say less than 5 small areas) then I take care of every other problem the puppy has and monitor the Demodex. If it is generalized I recommend t start bathing, spell out the complete problem list and see how they respond initially.  I usually save the most aggressive treatment plan for a few weeks down the road, because in almost all cases if you get them out of the stressful environment, feed them, bathe them, spay/neuter, de-worm, and start to treat the secondary skin infection the immune system kicks the buggers to the curb. (Disclaimer time: do all of this under the advisement of your vet. This battle is best won with a team approach).


Here's where todays story starts.
I have seen two cases of adult onset Demodex over the last few weeks. Odd, because it has been years since I have seen one. 

Lilly, at her initial visit. Red skin and patchy hair loss.
The bloody spot above her wrist is from her skin scrape.

Lilly was the first case. She is an eleven year old spayed yellow lab. She has a life of love, a devoted family, and every need is met by a soft hand, and a smile. She has never been left alone. Literally. She has a fellow lab to keep her company, should her family all be called out together. But on almost every instance one member stays home with them to keep them company.

Lilly on her first visit had very red inflamed skin, generalized hair loss and the moment I saw her I thought, "Huh, she looks mangey." A skin scrape later it was confirmed. She was literally crawling!

We started talking about her overall health to try to uncover what had caused her to become susceptible to her infliction.

Lilly's constant companion, her moms mother had been ill for about a month and had recently passed away. Over that month the family had to leave her for much longer than normal periods of time.

She had also been with us boarding for a week. Lilly was stressed out! Demodex saw a crack in the normal unpenetrable exterior and took hold.

Her mom and I went on a hunt for any other hidden illnesses. A full blood work, urinalysis, and physical exam lead to no leads. We started her on Lyme sulfur dips, (not pleasant) and discussed a thorough treatment plan.

This is what the same area looked like a week later.

A little less red, but still significant hair loss.
A blood test was sent to Washington State to check for ivermectin sensitivity. This is can either be by blood or mucosa swab. I conferred with my local veterinary dermatologist about this and he recommended blood. It is a bit more expensive to ship, and the test takes a few days to be returned, but I have lost one German Shepherd to ivermectin (not for this disease, and not prescribed by me, but none the less a sad terrible loss), so, I check almost all of the dogs before I start treatment.

Update; Buddy and Lilly came in last week (4 months of treatment so far for Lilly). She looks perfect! I almost couldn't tell them apart her skin looks so good. She still needs two more negative scrapes, but I'm sure she will pass those with flying colors!

July 2014. Lilly's mom came to see me after she found a few areas of red skin and thinning hair. She feared that the Demodex was back. A skin scrape later I confirmed her suspicion. It seems that the Demodex appeared again this year after a week at the beach, just as it had done the year before. Lilly's mom was afraid that she was "catching the Demodex" at the beach.

There is some difference in opinion as to the exact origin of Demodex. Most of us believe that Demodex is always there, lurking, waiting, and emerges in an explosion after a stressful episode. So even though Lilly loves the beach, for her body the sun, surf, and change in environment causes her older immune system to be challenged enough to let the bugs proliferate.

I called my good friend, and Dermatology expert Dr. Vaughn, who told me that every once in a while they see a dog who seems to need to stay on ivermectin indefinitely. She also reminded me that you cannot stop treatment until you get two consecutive monthly negative (no evidence of mites at all) skin scrapes. She also places these stubborn cases on Advantage Multi monthly year around indefinitely.

This is Mac. He is an older German Shepherd. He came to me for a second opinion because his skin was worsening in spite of being to his regular vet three times. Every time he went for a re-check he was given the same antibiotic and ear ointment. 

When I first walked into his exam room I almost cried. He was one of the most pitiful desperate cases. It was so overwhelming (and his dad was on a pretty tight budget), that I called the dermatologist and asked for an emergency transfer. I did not want to miss anything on his treatment plan. Mac had not a second to spare. He was a bag of bones, infection from head to toe, and severely depressed.

I wanted to give you some idea of how long it takes to treat this disease, but also how rewarding it is!

This is Lilly two weeks after she has started her ivermectin treatment. The skin is less red, but the patchy  diffuse hair loss is still generalized and noticeable.

Lilly's ivermectin screen came back normal. Even with the tox screen done we started her daily oral ivermectin treatments at a very low dose. The dose was gradually increased daily to get to the treatment dose. It took almost three weeks to get her at the effective treatment amount. During that time she was watched very closely for any adverse side effects.

To try to arrest the progression of her mange assault we started her on weekly lime sulfur dips. It was largely ineffective, but it is a relatively safe option while you wait for the sensitivity screen.

This is Mac about a month after he started his treatment.

His feet are no longer bleeding, and he has put on 15 much needed pounds.

Here again is Lilly, about 5 weeks into her ivermectin treatment.

Her hair is growing back, her skin is not as red, and she is so much happier.

Mac again, about 6 weeks into his treatment.

He has put on another 3 pounds, (primarily because he isn't draining blood, serum and feeling so rotten). He can walk better, (it is physically terribly painful to try to walk on feet with open wounds that are swollen).

Both Mac and Lilly return monthly for skin scrapes. We are looking for those little Michelin men at each visit. We do not stop treating until there are three consecutive (month apart) scrapes. I would guess that both of these guys will be visiting monthly for about 4 to 6 more months..

If you have any pet questions you can find me at or on Twitter @FreePetAdvice.

Have you hugged your pet today? I hope so! Life is a fleeting precious thing. Remember to take a moment and tell them that you love them. They can hear you.

Always be kind.


  1. Thanks for hopping on to TNT Thursday. Oh no, demodex looks terrifying. I have a missing patch of skin on my R elbow that my sapiens just discovered. Makes me worried that this could be related.

  2. Kei, the most recent addition to my pack, was a demodex puppy. She was rescue from a remote regions of our province where there is virtually no access to veterinary care - she had been found in a dumpster, suffering from a severe case of demodectic mange. After several months of treatment, as well as plenty of TLC from an awesome Foster Momma, she now looks amazing!

    Her journey to health is shown in my profile picture. She is now a happy, healthy little girl, whose greatest joy in life is the hours spent wrestling and playing with her new BFF, my collie rescue (Laddie).

    1. thank you for reading!! Here's wishing you many happy healthy years to come for you both!

  3. What are the potential causes of Demodex? My Boston Terrier has had one cast every year from 2012 until today. My vet thinks there may be an underlying cause, wants to to charge a ridiculous amount of fees to test him. He's 9 and each time we treat this, it goes away just to return in a year's time. I don't trust my current vet to give me to the full story and feel that, perhaps, they are more concerned with funding their facility than helping my dog,

    1. Hello,
      In older dogs there can be many possible underlying causes, and yes these should be explored. Also discuss what you need to do for life long therapy. Good Luck!