Mange is a skin problem in dogs that is especially common among strays, and those that are neglected or abused. The condition is caused by several species of mites, the most common of which are sarcoptic and demodectic mites.
Mange is more than just an ordinary dog rash. Affected dogs suffer from pain and discomfort as intense itching causes them to engage in a frenzy of scratching, biting, and chewing all over their bodies. Persistent scratching can eventually cause hair loss and breaks in the skin surface, paving a way for secondary dog skin infection caused by bacteria.
Sarcoptic mange is caused by the mite Sarcoptes scabei. It’s the same mite that is associated with scabies in humans. As mites burrow under the skin, they cause extreme itching. The persistent scratching and chewing can eventually lead to hair loss particularly on the dog’s legs and belly. Without prompt medical intervention, the dog’s skin becomes thick and dark in color. Though the mites are unable to complete their life cycle when they infest humans, they will, however, cause severe itching until they die.
The mites are very prolific. They burrow underneath the surface of the skin and lay eggs. In 3-10 days, the eggs hatch into larvae that eventually develop into adults.
How do dogs get sarcoptic mange?
Dogs can get infected by sarcoptic mange through direct contact and from contaminated surfaces, such as shared bedding or even the carpet.
Signs of Sarcoptic Mange in Dogs
Sarcoptic mites prefer parts of the skin that are hairless, so the most likely areas that are infected first are the dog’s ears, armpits, and belly. The persistent scratching, chewing, licking, and biting cause the skin to become red and inflamed as it becomes more irritated, eventually causing hair loss. There may also be the formation of scabs and crusts. Open sores provide easy access to secondary infections. Without proper treatment, lymph nodes can become swollen.
The good news is, sarcoptic mange can be treated. But it is extremely contagious and can easily be transmitted to humans and other pets in the household, making it an important zoonotic disease. Dogs with sarcoptic mange need to be separated from the rest of the household. Quarantine is necessary to avoid mite transmission. It will also give enough time for the decontamination of the dog’s immediate environment.
In dogs, demodectic mange is caused by the mite Demodex canis which usually inhabits the skin and hair follicles of dogs. It’s the most common form of mange affecting dogs. The mite is virtually found in all dogs. Puppies get the mites from their mother a few days after birth. Unlike sarcoptic mange, cases of demodectic mange are usually not as serious. Also, it’s not contagious to other animals or humans. Healthy dogs can have demodex mites without exhibiting any symptoms. But when the dog’s immune system is compromised, the mites can rapidly multiply and start an infection. Puppies, with their still-developing immature immune system, also tend to be more prone to skin mite infestation. Demodectic mange is also more common in older dogs because of the age-related decline in their immune system function and integrity. Certain medications can also increase a dog’s risk of demodectic mange.
Signs of Demodectic Mange in Dogs
Dogs with demodectic mange often have skin that appears very red and inflamed, thus the condition is also called ‘red mange’. Unlike sarcoptic mange, dogs with demodectic mange don’t suffer from severe bouts of itching. But there will be hair loss that usually occurs in patches. Hair loss usually starts on the dog’s face, especially around the eyes.
Forms of Demodectic Mange in Dogs
Localized – Demodectic mange in dogs is said to be ‘localized’ when there are only several patches of hair loss.
Generalized – When the loss of hair affects many areas of the body. The majority of generalized cases occur in dogs under 18 months of age, most of which have an immune problem.
Demodectic Pododermatitis – When only the paws are affected and secondary bacterial infections are common. Shar Peis and Old English sheepdogs have been observed to be more prone to this form.
How Mange is Diagnosed
After a thorough physical examination, your veterinarian will get deep skin scrapings which will be examined under the microscope for any signs of the mites. Demodex mites are cigar-shaped mites with eight legs. There have been cases when demodectic mange is an incidental finding when a skin biopsy is performed in dogs suffering from chronic skin problems that fail to respond appropriately to treatment. On the other hand, sarcoptic mites look like very small spiders.
Treatment of Mange in Dogs
The usual treatment regimen for the localized form of demodex in dogs involves administering topical medication. But more aggressive treatment is required when dealing with generalized cases. It involves the use of specially formulated medicated shampoos and dips, coupled with oral medication. A shampoo that contains benzoyl peroxide is applied to the affected dog to open the hair follicles before dipping.
There are also newer medications for demodectic mange treatment in dogs. These include spot-on or topical medications that contain imidacloprid and moxidectin as active ingredients. Take note, however, these medications are used ‘off-label’ for demodicosis treatment. This means that the medication is being used for conditions other than what it was indicated or approved for. Another medication that is used for off-label treatment of canine demodicosis is an injectable preparation of doramectin. It is a good idea to talk to your veterinarian about the benefits and risks of treatment options that are available for your dog.
Secondary skin infections are very common in generalized cases of demodectic mange. When present, the dog will require a round of antibiotics.
More severe cases of demodectic mange in dogs will require long-term treatment. Regular skin scrapings will also have to be performed to monitor the dog’s response to treatment.
Since the development of demodectic mange is a red flag indicating a compromised immune system, your veterinarian may also take measures to identify any underlying illnesses that may be responsible for compromising your pet’s immunity so the appropriate treatment can be given.
When treating mange on dogs, make sure that you follow the instructions of your veterinarian regarding the dosage and administration. And it’s very important to complete the full course unless your vet instructs you to stop or switch to another treatment option.
The treatment regimen of sarcoptic mange in dogs include the following:
Dips — The most common dips for dogs with mange are amitraz and lime-sulfur dip. In severe cases, dipping may have to be repeated every 4-6 weeks. Take note that mites can develop resistance to certain treatments, thus there may be a need to experiment to find the most effective medication or formula.
Topical medication — Common topical medications prescribed for sarcoptic mange in dogs contain selamectin, fipronil, imidacloprid, or moxidectin as the active ingredients.
Oral medications — May be in the form of liquid, tablet, or flavored chew. Most oral medications for mange in dogs are used ‘off-label’. The most common oral medications for sarcoptic mange include milbemycin, afoxolaner, fluralaner, and sarolaner.
Steroids may also be prescribed to reduce skin inflammation. These are available as creams for topical use or as oral medications (tablets).
While your dog is undergoing treatment, he will need to be quarantined to protect the other members of the pack — humans and animals alike. However, your veterinarian will likely recommend treating all the dogs in the household even if only one is exhibiting signs of infection.
Make sure that your dog is comfortable and stress-free while undergoing treatment because anxiety and stress can weaken his immune system and defeat the purpose of the treatment.
When handling your dog, be sure to wear gloves and wash your hands thoroughly with soap and water after. Everything that your dog has come into contact with — his bedding, your bedding, furniture, curtains, carpets, surfaces, etc– should be washed.
Potential Problems Associated with Topical Mange Treatment
Amitraz is the most common medication that is used for dipping in dogs with mange. It’s a strong insecticide that can cause serious adverse effects for dogs and humans alike if not properly used. A dog suffering from the side effects may vomit and appear sedated for 24-36 hours following dipping. Fortunately, these signs tend to resolve without medical intervention. If dipping your dog cause these side effects, try diluting the next dip by adding 25% more water.
Sometimes, a dog will lick at the spot-on medication that has been applied causing him to drool.
How can you protect your pet against dog mange?
Keep your dog away from areas where infected dogs or foxes frequent.
Discard bedding that your dog uses or wash it frequently in a solution that contains diluted bleach (1 oz bleach mixed with 1-gallon water).
Keep your dog healthy at all times to promote good immune system function and integrity. This can be achieved by feeding a complete and balanced diet, regular exercise, supplements, up-to-date vaccinations and preventatives, and avoiding exposing your dog to stressful situations.