Demodectic mange, often referred to as red mange, is a parasitic skin condition affecting dogs, caused by microscopic mites such as Demodex canis, Demodex injai, or Demodex cornei. These cigar-shaped mites with eight legs are naturally present in a dog’s hair follicles. Normally, a healthy immune system keeps these mites in check, preventing any issues. However, when a dog’s immune system is immature or compromised, these mites can overgrow, leading to clinical signs like hair loss and red, scaly skin lesions.
The mite is typically transmitted from mother to puppy during nursing due to the puppy’s underdeveloped immune system. Direct exposure to a dog with demodectic mange is not a risk for healthy dogs, as the condition requires a weakened immune system to manifest. Importantly, demodectic mange is not contagious between adult dogs, nor can it spread to humans.
Symptoms of Demodectic Mange
Key clinical signs of demodectic mange in dogs include:
- Alopecia: Hair loss, often in patches.
- Skin scaling: Dry, flaky skin.
- Papules: Small, raised bumps on the skin.
- Hyperpigmentation: Darkening of the skin.
- Skin thickening: The skin may become leathery.
- Pruritus: Itching can vary significantly, depending on the presence of secondary skin infections or whether the mange is localized or widespread.
In puppies, lesions frequently appear around the face and head, stemming from contact with the mother’s milk. However, these lesions can develop anywhere on the body. Severe, generalized cases may present with pain, lethargy, fever, oozing wounds, and swelling. If the mites invade the ear canals, ear infections can also occur.
Causes of Demodectic Mange
Demodex mites are normal inhabitants of the skin and usually cause no harm. Mange develops when an overgrowth of these mites occurs within the hair follicles, particularly in dogs with weakened immune systems. This includes puppies with developing immune systems and older dogs suffering from underlying illnesses that suppress immunity. Demodex mites are present on all dogs and even humans, but overgrowth only occurs when the immune system is compromised.
Diagnosis by Veterinarians
Veterinarians typically diagnose demodectic mange through skin scrapings, hair plucking, or cytology. These non-invasive tests involve scraping the skin deeply enough to cause minor irritation or bleeding, as Demodex resides deep within hair follicles, or by collecting hair at the root. The samples are then examined under a microscope, and the presence of any mites confirms a positive diagnosis. In some instances, mites may be detected through fecal flotation or testing, as dogs may ingest them while licking affected areas. Polymerase chain reaction (PCR) testing is also an option, though it can sometimes yield false negatives and is often not required when the diagnosis is clear. Skin biopsies might be necessary for cases that do not respond to treatment or when other diagnostic methods are inconclusive, especially in severe, generalized instances.
Treatment Options
Not all cases of demodectic mange necessitate treatment. Mild, localized infections often resolve spontaneously within one to two months without intervention. For other localized cases, topical medications like moxidectin and imidacloprid may be prescribed.
When mange becomes generalized, medication is usually recommended. Miticidal treatments, administered orally or topically, are the most common therapies. These include medications such as ivermectin, milbemycin, doramectin, amitraz, fluralaner (Bravecto), afoxolaner (Nexgard), sarolaner (Simparica), and lotilaner (Credelio). It is crucial to note that dogs with MDR1 mutations must never receive ivermectin, as this can have severe consequences. This mutation can be identified through genetic testing. The best flea and worm treatment for dogs might be discussed with your vet as part of a broader parasite control plan.
Miticidal therapy continues until two consecutive negative skin scrapings or hair plucking tests are achieved. Special shampoos containing benzoyl peroxide are often recommended to open and cleanse hair follicles, allowing topical treatments to penetrate more effectively. Owners should discuss the risks and benefits of any prescribed medications with their veterinarian. Secondary skin infections, common due to inflammation, may require antibiotic therapy and might need to be treated before the demodectic mange itself can be cleared. It is also advised to avoid breeding dogs diagnosed with generalized demodex infections, as the condition is believed to have a genetic or immune system component contributing to mite overgrowth.
Recovery and Prevention
With appropriate and timely therapy, most dogs recover well from mange. Persistent cases often stem from secondary infections or underlying systemic illnesses that require management. Without proper treatment or if underlying medical conditions are poorly managed, mange can be fatal.
Environmental cleaning is generally not required for demodectic mange, as it does not typically transmit between dogs. However, monthly or tri-monthly miticidal preventatives are still recommended to safeguard against other mite types, fleas, and ticks, unless otherwise advised by a veterinarian. Regular parasite prevention is a key aspect of maintaining a dog’s health. For comprehensive parasite management, exploring the best flea and worm treatment for dogs can be beneficial.
Frequently Asked Questions about Demodectic Mange
Is demodectic mange contagious to humans?
No, demodectic mange is not contagious to humans.
How long does it take for demodectic mange to resolve?
Resolution time varies from weeks to months, depending on whether the infection is localized or generalized, and the presence of secondary infections or underlying health issues. Each dog responds differently to treatment, so there is no exact timeline.
Can mange resolve on its own?
Yes, mild cases of demodectic mange can resolve spontaneously, typically taking one to two months for localized infections.
How long is a dog contagious with demodectic mange?
Dogs with demodectic mange are not contagious to other dogs, pets, or humans. This condition is linked to the dog’s immune system, not external transmission. Understanding mite treatment for dogs pets at home can help manage symptoms if recommended by a vet. For severe infestations, consulting about demodex mites in dogs how to get rid of it is essential.
Featured Image: iStock.com/Todorean Gabriel
