Mite-y Matters: Mange in Dogs
You’ve probably heard the phrase mangy dog. As in your mom saying, “Stay away from that mangy dog!” But what, exactly, does the adjective mangy mean? And, more importantly, could your dog ever be described as mangy?
Mangy means having mange
Mange is a skin disease caused by microscopic mites living on or in a dog’s skin and hair follicles. Some of these mites are normal residents of canine skin, but others aren’t. These common external parasites can produce mild to severe skin infections if their populations are allowed to grow unchecked.
The two most common types of mange in dogs are demodectic mange and sarcoptic mange (also known as scabies), and they’re caused by different species of mites. Demodex canis, the most common cause of demodectic mange, lives deep in hair follicles. In contrast, Sarcoptes scabiei canis, the mite responsible for canine scabies, can be found living just under the surface of the skin. Both the mites and the skin diseases they produce share similar characteristics; however, there are also important differences.
Demodectic mange is more common, especially in young dogs
All healthy dogs have a few Demodex mites living among the bacteria, yeast and other naturally occurring microorganisms on their skin. Nearly every mother dog carries and directly transfers these mites to her pups within the first week of life.
As long as a dog’s immune system is working properly, small numbers of demodectic mites won’t cause problems — the immune system keeps the number of mites in check and no signs of skin disease are seen. But in dogs with compromised immune systems, like puppies who receive poor nutrition or are infected with other parasites, or dogs with chronic disease, the mite population can grow to excessive numbers. Since the mites prefer to live in hair follicles, hair loss is typically the first visible sign of a problem.
There are three types of demodectic mange seen in dogs:
Localized demodectic mange, the most commonly seen form, occurs most often in young dogs (3 months to 1 year of age) whose immune systems are developing. In these cases, mite populations “bloom” in one or two small, confined areas, producing scaly bald patches and creating a polka-dot appearance in the coat. The most frequently affected body areas are the face, around the eyes, mouth and ears. However, demodectic mange can also be found on the front legs and, occasionally, the trunk of the body. Reddened skin is common, but itching is not.
Generalized demodectic mange affects larger areas of skin (more than five spots) or the entire body. A dog with this form of mange often develops secondary bacterial infections, which are very itchy and smelly. Generalized mange could signal an underlying hereditary condition, an impaired immune system, an endocrine system disease (such as Cushing’s syndrome, hypothyroidism or diabetes) or other health issue.
Demodectic pododermatitis is one of the most difficult forms of demodectic mange to diagnose and treat. In these cases, mange is confined to the paw and accompanied by bacterial infection.
Sarcoptic mange is highly contagious
Sarcoptic mange is an extremely itchy skin condition caused by mites that are easily transferred between dogs and even from dogs to people. Unlike demodectic mange, which is seen most frequently in young dogs, scabies can develop in dogs of any age, breed or gender.
The female sarcoptic mite tunnels into the upper layer of skin (the epidermis) where she lays eggs. This burrowing produces intense itching and inflammation of the skin, causing a dog to frantically scratch. Dogs with sarcoptic mange may also have hair loss, reddened skin, sores and scabs, with the most commonly affected areas being the ears, elbows, face and legs. However, if left untreated, scabies can rapidly spread to a dog’s entire body.
If passed to people, sarcoptic mange mites cause a rash of red bumps.
Does nutrition play a role in mange?
Nutrition may help play a role in managing demodectic mange, but not sarcoptic mange. Dogs pick up sarcoptic mites by coming into direct contact with an infested dog — improving a dog’s nutrition won’t change the risk for infestation.
Experts don’t completely understand why some dogs develop demodectic mange while others don’t. They suspect the underlying cause is a defect of the immune system. However, genetics, poor nutrition, stress and breed have been associated with demodectic mange in young dogs. Since a good diet is important to a dog’s overall health, providing a complete and balanced dog food to pregnant dogs throughout their lives — not just before and after whelping a litter — is important to creating a healthy immune system for her and her puppies.
If you have any concerns about your dog’s skin health, or if you’re thinking about breeding your dog, be sure to talk with your veterinarian. Not only can your veterinarian determine if your dog has a skin condition, but he or she can recommend an appropriate diet for your dog, whether you have a puppy or an adult dog.