Does Your Dog's Mange Make your Skin Crawl?

                                                                 

                        Adopting a dog is an exciting time for pet owners.  But, what do you do if that new bundle of fur has a skin disorder?  Soon after entering a new home, all dogs should have a veterinary exam to begin immunizations, deworming, and heartworm preventive medication.  This visit also provides an opportunity for veterinarians to conduct a full wellness exam and to diagnose diseases, including skin disorders that may be contagious to humans. 

 

                        A primary health concern for dog owners is “mange,” or mite infestation of the skin.  While there are multiple different mites pets may acquire, two types of mange are most common.  These include demodectic mange or “demodecosis,” and sarcoptic mange, commonly referred to as “scabies.”  Specific diagnosis of each of these infestations is made via microscopic examination of deep scrapings of multiple skin lesions on affected dogs.

 

                        Demodecosis is also referred to as “puppy mange” or “red mange” because it is more commonly diagnosed in puppies and is associated with reddening of the skin. The typical presentation is a young puppy with hair thinning, especially on the forehead or extremities.  This condition is generally not itchy, and when mild, does not require treatment. 

 

                        While demodecosis is usually localized, it can be generalized on the entire body and will be harder to eliminate when it affects the toes. Some short-haired dog breeds are over-represented with this disease, including Boston Terriers, Dobermans, Bulldogs and Pitbulls.  It is important to note demodecosis is not contagious to other pets or to humans!

 

                        The Demodex canis mite spends its entire life cycle on the dog.  Why these “normal inhabitants of the skin” begin to proliferate by the thousands is not known, however, a genetic or immunologic abnormality is the most likely cause.  If five or more areas of hair loss are diagnosed on a patient, the disease may be considered genetic and the dog should not be used for breeding. 

 

                        Treatment of demodecosis when warranted, varies from the use of topical products (rotenone ointments, benzoyl peroxide gels, amitraz dips) to oral anti-parasitic drugs (e.g. milbemycin).  Your veterinarian will likely perform follow-up examinations to insure that your dog’s demodecosis has entirely resolved.  Since this is potentially a genetic and/or immune disorder, recurrences are possible during times of stress.

 

                        Unlike demodectic mange, sarcoptic mange is contagious to other dogs AND humans via direct contact, and will be intensely itchy! Greater than 50% of the dog’s waking hours will be spent scratching due to irritation associated with the mites’ feces.  This mite, Sarcoptes scabiei, actually burrows under the skin but can live off the host in the environment for a few days. Scabies mites will reside in kennels, grooming shops and on pet bedding.  There is not a breed predilection with this mite infestation, but dogs that travel to shows, stay in kennels, or live outdoors are more likely to encounter this mite.

 

                        Lesions seen with scabies are most commonly found on ear edges, elbows and undersides of dogs, but may be anywhere on the body.  While it is easy to find multiple cigar-shaped demodex mites in skin scrapings, locating the globoid sarcoptic mite is much more difficult.  So much so, that scabies is usually diagnosed based on clinical appearance of the skin and response to treatment.

 

                        The onset of symptoms with scabies is usually sudden, and not all dogs in a household will experience the same intensity of itching.  The history for scabies patients often includes that the dog originated from a puppy mill or breeding kennel, traveled to dog shows, was exposed to straw, wood, or mulch, or lives in an environment with scabies infested squirrels or fox. 

 

                        Scabies may be treated either topically (selamectin, amitraz, lime sulfur dips), or orally (ivermectin).  Because the source of scabies mites is often difficult to identify or eliminate, once cured, these patients should be placed on selamectin (Revolution ), a monthly, topical heartworm preventive known to treat and control sarcoptic mites.  The dog’s environment should also be treated by disposing of contaminated bedding and cleaning all surfaces with 10% bleach solution repeatedly.

 

                        Owners of dogs diagnosed with sarcoptic mange are themselves most likely to acquire a self-limiting scabies infection on exposed areas of skin such as the wrists, abdomen, and neck from handling the infested dog.  Contact your physician for treatment advice if you think you might be experiencing a scabies infestation from your dog.

 

                        Pets can harbor other skin diseases besides mange that are contagious to humans so please be certain to consult your veterinarian if your furry family member is itchy or has skin lesions.

 

 

By Dr. Bonnie Jones