At some point in our lives, most of us have come across the trope of the “mangy dog” in a cartoon, book, or movie. Maybe some of us have even seen one in our travels or in photographs. The picture usually isn’t pretty.
The dog is often missing most or all of its hair, is covered in crusts and scabs, and is itching incessantly. Such a sight can look alarming, and the situation can seem almost hopeless. But is it? What you might not know is that mange is caused by not one, but two different mites. They are called Sarcoptes mites and Demodex mites and are a type of arachnid. This means that they have eight legs, just like ticks and spiders, but unlike spiders, mites can only be seen with a microscope. Today, we are going to take a closer look at these parasites, how they differ, and how we can successfully treat them.
The first form of mange is called sarcoptic mange and is caused by a mite called Sarcoptes scabei. It causes the form of mange called scabies. Scabies mites are considered transmissible – they can be passed from one dog to another. Sometimes, they can even be passed to other animals, like cats, or even to humans.
The good news for cats and people, however, is that these mites cannot live on any species other than dogs for very long and will quickly die. The bad news is that they can still cause us to break out in a rash. In dogs, infection usually starts at the elbows, belly, and ear margins before progressing to the rest of the body.
If a dog is seen for a skin condition, one of the first recommended tests is a skin scrape to look for mites. In this test, the surface of the skin is scraped to remove some skin cells and debris and is then examined under the microscope. Unfortunately, scabies mites are very difficult to find with this test and even if the test is negative, a treatment trial will usually be recommended.
The second form of mange is called demodectic mange and is caused by a mite called Demodex canis. Demodex mites are generally considered “normal flora” – or organisms that are usually found on or within the skin. In fact, we all, dogs and humans, have bacteria, fungi, and even mites that live in harmony with us.
But sometimes, this harmony is broken, and the mites can start to take over and may cause three different types of skin issues. Most commonly, demodex mites will cause localized infections. These commonly occur in puppies and may look like small rings of redness or hair loss around the eyes or on the face. About 90% of these cases resolve without treatment. Demodex mites can also cause generalized infections in which large portions of the skin are affected. This most commonly occurs in dogs under 1.5 years of age and usually resolves once their immune system matures. Usually, treatment is recommended to help alleviate symptoms, but most symptoms will begin to resolve without treatment once the dog is over 1 year of age.
If this occurs in an older dog, it is usually considered a sign of a more serious underlying health condition like cancer or immune system dysfunction. These dogs will require a full medical examination and labwork before undergoing treatment. Finally, some dogs, like Shar Pei and Old English Sheepdogs, can have infections that only affect their feet between their paw pads. Unlike the other forms of demodex infections which can be easily diagnosed with a skin scrape, this form often requires a biopsy to diagnose.
Treatment for both types of mites used to be much more challenging than it is today. Previously, topical dips such as foul-smelling lime sulfur dips were the mainstays of treatment. Some people would even dip dogs in motor oil to kill the mites, which could be quite toxic for the dog. Fortunately, we have much better treatment options available today.
Oral flea and tick medications in the Isoxazoline category will readily kill both types of mites and are safe and effective for all breeds of dogs. Injectable medications, like Ivermectin, may also be recommended. Your veterinarian will counsel you on the best treatment options for your dog. For older dogs that develop generalized demodex mange, treatment can be more challenging, and they may need to be on treatment long-term to keep symptoms under control.
The most important part of treatment is to always discuss with your veterinarian any treatments you plan to perform at home before administering them. In the past, it was popular to treat mites by dipping the pet in motor oil. However, this can be extremely dangerous and toxic to your dog as the motor oil can be absorbed through your pet’s skin leading to kidney damage, liver damage, and dangerous drops in blood pressure.
Additionally, severe and even fatal pneumonia can occur if your pet inhales any of the oil. Always ask your veterinarian before trying at home treatments for mites.
Mange in dogs is both a startlingly severe and highly treatable skin condition. Unfortunately, it is often visually indistinguishable from many other skin conditions including flea allergies, food allergies, environmental allergies, and even autoimmune conditions.
At the first sign of a skin issue, it is important to see your veterinarian to help determine what is causing the issue. Sometimes, it is even possible for there to be more than one problem at the same time and these can be difficult to work out. Fortunately, many of these conditions, including mange, can be successfully cured or managed allowing pets to live happy, comfortable lives.
Elizabeth Collins, VMD is a veterinarian at Karing for Kreatures Veterinary Hospital in Lemoore.