How to Treat Demodectic Mange in Dogs
Treatment for mange (demodex) infection in dogs and cats varies depending upon whether it is a localized or generalized mange infection.
About 90% of young, healthy pets with localized mange infection get better within two months even if they are not treated. These pets may benefit from a topical antibacterial agent such as Be Super Clean. The shampoo doesn't rid pets of demodex mites but it does help prevent bacterial skin infections that are caused by scratching.
In pets with generalized mange infection, those that are less than a year old have a 30-50% likelihood of clearing the infection even though it is widespread. These pets clear the infection because their immune systems kick into gear and they do not necessarily need medical treatment. For pets that do not spontaneously clear an infection, a prescription medication such as sulfurated lime or amitraz (Mitaban Dip for dogs) is used.
A combination of sulfur and lime (sulfurated lime) is used to kill bacteria, parasites and fungal infections on pets including mange demodex mites, sarcoptes scabiei mites, and ringworm. Sulfurated lime also relieves itching caused by parasites and ringworm.
Solutions of sulfur and lime are used as a rinse or dip every 5-7 days to treat mange (demodex) infections. Treatment is repeated for several weeks until skin scrapings have been clear of mites for at least a month. Sulfurated lime is safe to use on dogs, cats, puppies, and kittens at a dilution of four ounces in one gallon of water. If this concentration does not clear the mite infection, the concentration of sulfurated lime can be doubled to eight ounces per gallon of water.
Unfortunately, sulfur causes an offensive odor and the dip should be applied in a well ventilated room. The smell becomes less noticeable after the dip dries. Dip is left on the skin and is not towel dried, and your pet is not washed or allowed to get wet between treatments. Sulfurated lime dips stain jewelry, porous surfaces such as cement, and the white or light-colored coats of pets. The stained coat returns to a normal color over time. Bathing your pet with a benzoyl peroxide shampoo before dipping opens skin follicles and increases mite exposure to the dip.
Amitraz is a chemical (triazapentadiene) that kills insects and spiders on plants and pets. One of the formulations of amitraz is Mitaban Dip (for dogs). In veterinary medicine, amitraz is used to kill ticks, mites, and lice. Amitraz is approved by the FDA to be used weekly in dogs at least four months of age. Amitraz use in cats is "off-label" use. For pets with infections that do not clear with weekly dips, veterinarians may prescribe more frequent dips or may prescribe dips at higher concentrations than normally used. Either of these treatments is considered "off label" use of amitraz. Even with these modifications, up to 20% of adult pets with generalized demodex infection don't improve.
Amitraz dips are done with a veterinarian's guidance because amitraz is mildly toxic. The following recommendations help make the dip effective and safe for you and your pet:
- Don't use on pets with deep, draining bacterial infections. Clean up skin infections first.
- Clip your pet's hair unless it is naturally short.
- Bathe your pet with a benzoyl peroxide shampoo before dipping. This bathing opens skin follicles and increases mite exposure to the dip.
- Put protective eye ointment in your pet's eyes and cotton balls in the ears to avoid getting dip in them. Gently sponge areas around your pet's head and don't get dip in the lips or mouth.
- Cover the entire rest of your pet with dip.
- Leave the dip on and do not towel it off or rinse it off. Don't let your pet swim or become wet between treatments.
- Repeat the dip every 1-2 weeks until skin scrapings have no live or dead mites for at least a month. Skin scrapings are taken from bald areas and from normal-haired areas.
- When applying the dip on your pet, wear protective clothing and remove jewelry, which is discolored by amitraz.
- Work in a well-ventilated place but do not allow your pet to get cold.
For dogs with demodex paw infections, some veterinarians recommend soaking your dog's paws in amitraz mixed with mineral oil. This is "off label" use, but can be highly effective.
Amitraz is a powerful medication and it can cause side effects in dogs. Most dogs become lethargic after being dipped. Amitraz is most likely to be toxic to toy breeds, senior pets, weak pets, cats, and rabbits. Toxic effects include high blood sugar, vomiting, diarrhea, unsteadiness (ataxia), and slow heart rate.
Amitraz should not be handled by people with diabetes or by people taking MAO Inhibitors such as Parnate and selegiline. Amitraz should not be used on dogs taking Anipryl or Selegiline for Cushing's Disease and Canine Cognitive Dysfunction Syndrome (senility). Sulfurated lime is a safer medication for these pets.
If the mange (demodex) infection is not cleared by sulfurated lime or Mitaban Dip, or to increase the speed with which an infection is cleared, efforts are made to:
- Resolve stress, such as pregnancy
- Boost the immune system
- Clear underlying diseases or infections
- Give your pet Heartgard Plus Chewables (ivermectin, for dogs) or other medication prescribed by your veterinarian.
The approved treatments for mange (demodex) are sulfurated lime or amitraz, but when they are not effective, veterinarians may recommend using high doses of the prescription medications, such as Heartgard Plus Chewables (ivermectin).
Heartgard, which is used at 6 micrograms/kg/month to prevent heartworm infections, is given at 100 times the heartworm dose (600 micrograms/kg/day) for 2-3 months to clear demodex infections. Treatment is continued until dogs have skin scrapings with no live or dead mites for at least a month.
Interceptor (0.5-0.9mg/kg/month) is a commonly used medication to prevent heartworm infections. To treat demodex mites, veterinarians prescribe higher doses (0.5 to 2.0 mg/kg) used daily for several weeks. Interceptor is continued until skin scrapings are negative for live or dead mites for at least a month.
Because the high doses of Heartgard or Interceptor necessary to rid pets of demodex are potentially dangerous, two important precautions are taken. First, before treatment, dogs undergo testing to confirm that they do not have heartworms; and, second, they are tested to confirm they do not have the multiple drug resistant (MDR1) gene if they are purebred or mixed breed herding dogs:
- Australian Shepherd
- Border Collie
- English Shepherd
- German Shepherd
- Old English Sheepdog
- Longhaired Whippet
- Silken Windhound
Dogs with MDR1 gene are especially sensitive to certain medications containing ivermectin, such as Heartgard and Iverhart. Many veterinarians like to prescribe milbemycin given at a daily schedule for treatment of mange in dogs with the MDR1 gene. If you have a dog in the collie or herding breed, please contact your veterinarian for an alternative to medications that contain ivermectin.
Dogs that have both heartworms and demodex infections can still be safely treated. These dogs are first treated for heartworm infections with low doses of heartworm medication and then treated with high doses of ivermectin (Heartgard) or milbemycin to control demodex.
The Preventic Amitraz Tick Collar for Dogs contains amitraz and some veterinarians recommend using it "off-label" to help control mange demodex mite infections. The collar is most effective if worn between treatments of sulfurated lime or Mitaban Dip.
Cats are sensitive to amitraz, so your veterinarian may recommend mixing amitraz with mineral oil or propylene glycol (1:3 parts) and treating only the affected areas.
Without specific veterinary instruction, do not give your pet any oral steroids such as Prednisone and Prednisolone to treat mange. Nor should you apply topical medications containing steroids on pets with mange infections.
Pets with mange benefit from being given supplements containing fatty acids and antioxidants that boost the immune system.