Hi there XXXXXXXXXX,
Welcome to Just Answer! I would like to help you and your rescue dog with this question, but need a bit more information in order to better assist you.
Does the dog have any crusting and hair loss at the edges of her ear flaps?
Does she have any patches of hair loss around her eyes?
Do you have other pets in your home?
Is this dog on medications?
Who did the skin scrape (was it a vet?)?
Fiona
I noticed crusting on the ears. Hair loss was obvious on her body but not on her ears or face. I have 3 dogs in my home and 4 cats. We noticed the dogs scratching their bellies and ears and treated them with Revolution. One cat began biting between his toes, so we treated all of the cats with Revolution as well.
A vet did an initial skin scrape before the dog was placed in my home. The results were negative, but he did proceed to treat the dog with Ivermectin. She had her first Ivermectin injection about an hour before she came to me. After I returned the dog, the rescue owner took her to a second vet where another skin scrape was done, but it was also negative. This didn't really surprise me, however, because the dog had been treated with Ivermectin and the mites are difficult to find anyway, based on my research.
Thanks for that additional information!
I am going to go take a few minutes more to finish writing out a detailed answer for you... be right back!
Hi again XXXXXXXXXX,
There are 2 main kinds of mange that we deal with in dogs. They are demodectic mange and sarcoptic mange. Without examing a dog, I cannot diagnose what he or she has... but I can tell you what I would be leaning towards! Let me explain a bit more about them.
•1. Demodex.
This is a type of mange mite that is fairly common in pups and young dogs. Usually one just sees little areas of hair loss, the skin doesn't look angry or ulcerated. It is not particularly itchy. Often, the hair loss starts around the eyes, or on the lower legs, as little bald circles about the size of a dime or up to a quarter.
Here are some links:
http://www.peteducation.com/article.cfm?cls=1&cat=1352&articleid=729
http://www.petplace.com/dogs/demodicosis-red-mange-in-dogs/page1.aspx
http://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=630
You mentioned that your crew is itchy, which is not a big issue with Demodex.
With Demodex, it is easy to find mites on a skin scraping. Often, dozens of mites are found with a single scraping! Basically, if I do a few skin scrapings on a dog and do NOT find Demodex, then the dog does not have Demodex.
The treatment is fairly straight forward. Nowadays, most vets just use ivermectin by mouth or by injection daily. Or if this is just isolated to one spot, in just one animal, it is possible that your vet may suggest applying Lindane cream to the area three times daily to see if there is improvement. This is not nearly as effective, however.
•2. Sarcoptes
This is a type of mange caused by a mite called Sarcoptes Scabei, and it is also known as Scabies. It makes animals ITCHY!! I rarely see it here in Ontario, but saw it almost daily when I worked in California. (What a great learning opportunity for me!) Dogs with Scabies come in because they are so itchy. This type of mange causes itchiness long before it causes hair loss. The mite lives under the skin, and the itchiness seems to come from an allergic reaction to the mite. The classic symptom for Scabies is that the edges of the pinnae get crusty and ulcerated, and dogs scratch with a back foot when you rub the pinna, as you have described.
The good news is that this mange mite does not live long off the animal, and normal vacuuming and cleaning should get rid of them in the environment. Scabies is hard to diagnose, as skin scrapings are usually negative. It's just hard to find the mite because there can be so few causing so much itching. However, the good news is that they are fairly easy to get rid of by using Ivermectin every 1-2 weeks for 3 or 4 treatments total. Usually the dog is feeling MUCH better by 2 weeks into treatment which confirms the diagnosis.
I'll give you links to more information:
http://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=616
http://www.petplace.com/dogs/sarcoptic-mange-in-dogs/page2.aspx
http://www.peteducation.com/article.cfm?cls=2&cat=1589&articleid=764
http://www.canismajor.com/dog/mange1.html
And about sarcoptic mange in cats (which I have never diagnosed, as it is much less common):
http://www.petplace.com/cats/sarcoptic-mange-in-cats/page1.aspx
So, from what you are describing, Sarcoptic mange would be pretty high on my list of possibilities. If your dogs were my patients, I would treat them all with Ivermectin at 0.3 mg/kg by mouth once a week for a month. If they were not greatly improved by the 2 week mark, I would want to do further diagnostics to figure out what was going on.
If this has been helpful, please accept my answer and leave feedback. I will still be here to provide more information if you need it!
The above is given for information only. Although I am a licensed veterinarian, I cannot legally prescribe medicines or diagnose your pet's condition without performing a physical exam. If you have concerns about your pet I would strongly advise contacting your regular veterinarian.
Dog Veterinarian
15 years experience as a companion animal veterinarian in British Columbia, California and Ontario