Dogs itch for a lot of reasons, but no other skin problem causes as much itching as sarcoptic mange. Also known as “dog scabies,” sarcoptic mange is a common skin disease in dogs worldwide in every climate. It can occur in dogs of all ages and breeds, as well as humans and other animals.
The symptoms of sarcoptic mange are caused by an allergic reaction to the scabies mite burrowing into the skin and laying eggs. Infections cause a severely itchy skin rash with oozing yellowish crusts, fur loss, pustules and other health problems. Many dogs develop skin infections as a result of constantly licking or scratching themselves.
The good news is that there are many stories of people who have rescued severely mangy dogs and nursed them back to full health. If your dog is suffering from irritated, itchy skin, it is a good idea to make an appointment with your veterinarian right away. Early diagnosis of these symptoms will give you a head start on a cure for your dog.
What is Sarcoptic Mange?
Sarcoptic mange (“canine scabies”) is an intensely itchy skin condition in dogs that is caused by parasitic mites called Sarcoptes scabiei. These mites spread from dog-to-dog by physical contact. Sarcoptic mange is highly contagious, but it is easily treatable and rarely fatal.
Early Signs of Sarcoptic Mange in Dogs
Scabies mites prefer areas of skin with less fur, so the first place to look for symptoms will be the dog’s elbows, hocks, armpits, ears, chest, belly or groin. Look for hair loss in dogs, red skin and yellowish crusts, and pay close attention to ear tips and elbows where mange is usually worst.
How to Check Your Dog for Scabies Mites
Unfortunately, it is not always easy to tell if a dog has sarcoptic mange. You can part the fur and check for pin-point bite marks on a patch of bare skin, but you probably will not notice any mites. The mites are only 0.3 millimeters long and can barely be seen.
The females are larger, but they burrow very deep into the skin. Dog scabies is usually diagnosed when a veterinarian takes a skin scraping and looks at it under a microscope, but even a veterinarian may not find an actual mite. Less than a dozen mites can cause severe itching in some dogs, although major infestations can involve over one million scabies mites.
Symptoms of Sarcoptic Mange in Dogs
The incubation period for canine scabies is 8-10 days after exposure, but dogs who are infected may not show symptoms for 3-4 weeks. This is a big reason why mange is so contagious – dog owners may not realize their dog is infected, so they continue going about their normal routine while the mites spread.
Dog owners can get scabies too, so if you think your dog has scabies and you are checking him for symptoms, wear disposable gloves to avoid being bitten by the mites.
Pimples & S-Shaped Burrows
Male scabies mites stay on the surface of the skin, but female scabies mites create short zig-zag or S-shaped burrows down into the skin, often accompanied by small bug-bite pimples. You may see a pearly pimple at the end of the burrow that can be removed by a doctor and examined under a microscope to diagnose sarcoptic mange. However, burrows and pustules may be hidden by scratch-marks left by the dog.
Intense itching is the most common sign of sarcoptic mange in dogs. The itching becomes more constant over time as the mites reproduce. Dogs with scabies will frantically and relentlessly scratch, chew and bite their skin. They may be too uncomfortable to eat, drink, play or sleep normally.
The itching is usually worst at night when the mites are more aggressively burrowing deeper into the skin. Dogs who have never had mange before may not start itching for 3-4 weeks. Other dogs will start itching within hours of picking up their first mite — especially if they have previously had mange, because their immune system is already trained to respond with an allergic reaction.
Just a few scabies mites can cause severe itching in any dog, but it takes longer for symptoms to appear in dogs who have never had mange because they are not allergic to the mite’s droppings yet.
Symptoms in Non-Infested Body Parts
Sarcoptic mange is an inflammatory skin reaction that is caused by the dog having an allergic reaction to mite feces. Because the rash is due to an immune response to mite feces rather than the mites themselves, symptoms may occur in parts of the body that are not actually infested with any mites. Some dogs react more severely than others, depending on if they have had sarcoptic mange before or not.
Symptoms of a Scabies Skin Rash
The skin becomes itchy, erupts into red wart-like growths called papules, and oozes a substance that dries and forms crusty scabs. Scabies can spread all over the body if left untreated. Over time, small bumps become crusty yellow-gray sores on the dog’s abdomen, legs, ears, chest, or elbows. The skin may also thicken or darken as a result of scar-tissue buildup.
The symptoms of sarcoptic mange resemble the symptoms of other skin diseases in dogs — such as food allergies, chiggers, flea bites, bacterial skin infections (folliculitis), ear infections, or skin reactions caused by another type of mite called Demodex canis. Sarcoptic mange is easy to misdiagnose, even with a skin scraping by a veterinarian. But if scabies is misdiagnosed as an allergic reaction, anti-inflammatory cortisone shots will only relieve itching for 2-3 days.
What’s That Smell?
Dogs with sarcoptic mange often smell bad — not because of the mites themselves, but because bacteria and yeast take advantage of the situation. Mangy dogs will develop a strong, musty, unpleasant odor – with a particularly foul smell coming from their ears.
This symptom is canine seborrhea and it occurs when irritated skin over-produces a fatty substance called sebum. Bacteria and yeast feed on this substance and grow excessively, resulting in a pungent smell.
Dogs with mange frequently develop skin infections in the cuts, sores and wounds from constant scratching. You may notice bleeding, crustiness, hair loss, redness, pus or discharge from the infected skin. Skin infections in dogs can be deadly if they are not treated promptly.
One of the most common opportunistic germs is Staphylococcus, which is becoming increasingly resistant to the antibiotic methicillin. As a result, more dogs – and humans – are dying of infections that spread uncontrollably from their skin to their bloodstream (septicemia).
Sarcoptic mange will cause a dog to lose fur in characteristic patterns. Fur loss usually starts on the ears, elbows, legs or face, and later spreads all over the body. The dog may have mild thinning of the fur, large hairless patches, scattered bald spots, or all of the above.
There are two reasons why dogs lose their fur when they have sarcoptic mange. One is that they are constantly licking or itching irritated skin, which physically rips out the hair follicle. The other reason is that skin inflammation causes the hair to fall out. Matted fur is another problem – especially in dogs with advanced sarcoptic mange. Treatment always involves shaving or clipping off the fur to remove mites attached to the hair follicle. The fur will usually grow back after the dog is cured of sarcoptic mange, but it may be thinner.
Other Health Problems from Sarcoptic Mange
In its advanced stages, sarcoptic mange is a whole-body disease. The dog will show poor body condition, weight loss, fever, enlarged lymph nodes, fatigue, and listlessness. Dogs will have little interest in anything — including eating, drinking or defending themselves.
Even coyotes or wild dogs with sarcoptic mange can become approachable by humans due to a lack of energy, physical weakness, and poor vision and hearing. Untreated infestations will eventually lead to an excruciatingly slow and uncomfortable death. The dog can die of exhaustion, starvation, dehydration, or a bacterial infection if it does not receive medication.
Mite Bites on Humans
Finding mite bites on yourself is a sign that your dog may be infected. Mite bites look like patches of irritated bumps, like mosquito bites. You may notice a scattering of red spots where your clothing is snug, or have an itchy red skin rash on your arms, abdomen or chest.
Be aware that dogs with sarcoptic mange can spread Sarcoptes scabiei mites to people and other pets in your home. If the dog shares a bedroom or sleeps on beds and furniture, everyone in your house will start scratching soon enough. There have been reports where a family dog spread canine scabies to the kids, the kids spread it to their friends, and the friends spread it to their parents and pets. Suffice to say, scabies spread quickly and exponentially.
Luckily, humans are not a normal host species for Sarcoptes scabiei. The mites can burrow into human skin but they do not reproduce, so they will usually die in about 5 days, leaving behind an itchy skin rash for a week or two. Infections in people are not very serious, but they will return until the dog is completely cured of mange.
Life-Cycle of Scabies Mites
Sarcoptes scabiei can spend its whole life on a dog. Pregnant female mites will burrow deep into the dog’s skin and lay 2-3 eggs per day for 1-2 months. The eggs hatch in 3-5 days and the larvae move to the skin surface, spreading to other dogs, objects, animals, or people. The males impregnate the females and repeat the cycle. The whole life-cycle from egg to adult is completed within 2-3 weeks.
By the time a dog shows symptoms of sarcoptic mange, it may be infested with mites in all different stages of their life-cycle. Therefore, the treatment to cure dog scabies must be repeated for a few weeks. Your veterinarian may ask you to bathe your dog every week for 3-6 weeks in an anti-parasitic lime sulfur dip (LymDip). The dog will likely still be contagious during this time. Furthermore, other animals in your home might also need treatment to avoid the risk of re-infestation.
Long-Term Effects of Sarcoptic Mange
Most dogs will not have any long-term effects from sarcoptic mange if they receive treatment. However, ongoing itching is still a possibility because the dog’s body must eliminate the remains of dead parasites, heal a maze of tunnel wounds and necrotic skin, and remove irritating mite feces and debris from deep inside the skin.
How Long Do Symptoms Last?
It normally takes a few months for all the symptoms to go away, but it depends on the general health of the dog. Complications like skin infections, hair loss, or skin thickening will take longer to heal. Frequent medicated baths may be necessary to soothe irritated skin while the dog is recovering.
In severe cases of sarcoptic mange, it is not uncommon for the fur to re-grow very slowly, thinner, or in another color than it was before the dog had mange. Some dogs also suffer permanent scarring due to itching, or abnormal folds due to skin thickening. However, the fur will often eventually re-grow to hide the obvious long-term signs of mange.
Lifelong Sensitivity to Scabies Mites
Dogs who have recovered from sarcoptic mange will be highly allergic to the mites that cause scabies for the rest of their lives. If your dog is ever bitten again, intense itching will likely start within a few hours. Therefore, it is a good idea to keep a close eye on your dog and his playmates and remain vigilant for signs of sarcoptic mange.
If your dog begins scratching uncontrollably, something is wrong – and it’s not always fleas. Sarcoptic mange is a serious issue for homeless and feral dogs, but it has been known to affect pet dogs as well. If your dog starts itching, schedule an appointment with your veterinarian to determine the cause and the course of treatment.