Ask a Vet: Is Puppy Mange Contagious to Dogs and Humans?
My inbox has been awash with questions about the contagiousness of puppy mange. Here are two representative queries.
Is puppy mange contagious to other dogs? My son's 8-month-old Boxer has it, and she has been around my daughter's dog.
In your article about puppy mange, you said it's contagious. ... I have another puppy who does not seem affected ... but is it contagious to me? Should I stop him from sleeping on the bed?
I look forward to your answer.
Puppy mange (as it is known colloquially) is caused by mites from the genus Demodex. It also is known as demodectic mange, demodicosis, and red mange.
Demodex organisms are skin parasites. They are mobile. This means they can spread from one dog to another. However, in practice puppy mange is not contagious. There is a simple reason for this: virtually every dog on earth (except for newborn puppies) is already infested with the organism. You can't catch something you already have. And what about those newborns? Demodex mites from their mothers infest them when they nurse.
Demodex mites cause no problems in the overwhelming majority of dogs. However, they can cause hair loss or, less commonly, skin inflammation that leads to secondary skin infections in individuals whose immune systems can't keep the mites in check. Susceptible individuals include those with immature immune systems (puppies -- hence the term puppy mange) and some dogs who take immunosuppressive drugs or are malnourished or stressed.
Symptomatic demodectic mange comes in two varieties: a mild, or localized form and a severe, or generalized form. Dogs with mild Demodex symptoms exhibit patchy hair loss over small areas of the body (most frequently on the face and on the sides of chest, abdomen, and legs). The areas usually aren't itchy, red, or irritated. Existing patches often heal while new ones form, and the process of patch formation and healing may take several months to run its course. I generally do not recommend treatment for localized demodectic mange. (And I put my money where my mouth is: my pal Buster suffered from the localized form of Demodex for several months and I did not treat it. The symptoms resolved over time.)
The severe or generalized form of demodicosis leads to hair loss over large portions of the body. The skin may become inflamed, leading to itching and malodorous bacterial and yeast infections in the skin. Generalized demodectic mange often requires treatment with parasiticides such as amitraz or ivermectin, as well as treatment with antibiotics (for skin infections) and antifungal medications (for yeast infections). Be aware that amitraz and ivermectin should be used only under the supervision of a veterinarian.
Dogs that develop symptomatic demodectic mange most often are between four and 18 months old. Some dogs (such as my pal Buster) exhibit intermittent mild symptoms up to three years of age.
Canine demodicosis is not considered transmissible to humans. However, we do have our own species of Demodex. Like their canine brethren, our Demodex mites usually don't cause any skin problems, which is a good thing -- like their canine brethren, our Demodex mites are ubiquitous.
Go to my website to read more about Demodex in dogs: http://drbarchas.com/demodex