What Is Sarcoptic Mange in Dogs?
Sarcoptic mange, also referred to as scabies, is a communicable skin ailment caused by mites that reside within the hair follicles. This condition can be transmitted from animals to humans and poses a significant threat to affected dogs, occasionally resulting in fatality.
The underlying culprit behind sarcoptic mange is Sarcoptes scabiei, a microscopic parasite characterized by its small, circular, white appearance under the microscope. Adult mites possess eight legs, while juveniles have six. Notably, terminal suckers on their legs aid in feeding on the host’s skin. Despite their tiny size ranging from 0.2 to 0.4 millimeters, these mites cannot be discerned without magnification.
Transmission of these parasitic mites occurs readily among animals and can also affect humans. Foxes serve as primary carriers, making them a significant source of infestation for domestic dogs. Dogs exhibit allergic reactions to these mites, with even a few being sufficient to trigger severe clinical manifestations.
The reproductive cycle of sarcoptic mange mites involves adult mating on the skin surface, followed by females burrowing into deeper skin layers to lay eggs. Upon hatching, the larvae migrate towards the skin’s surface, initiating feeding on the skin. As they mature into nymphs and eventually adults, the entire life cycle spans approximately three weeks.
Typically, scabies inflicts dogs enduring starvation, neglect, or those with compromised immune systems. It is less commonly observed in healthy dogs living in nurturing environments.
Symptoms
Sarcoptic mange manifests through various clinical signs, including:
- Intense itching
- Alopecia (hair loss)
- Excoriations, which are self-inflicted wounds ranging from superficial to deep
Papules, raised bumps, are often observed on the chest or throughout the body. The mite’s preference for hairless skin leads to thick crusted areas, commonly found on the edges of the ears, ankles (hocks), armpits, and elbows. However, sarcoptic mange can affect the entire body.
Secondary skin infections frequently arise due to the presence of skin lesions, manifesting as crusted lesions (collarettes) or weeping wounds. Dogs may exhibit depression, decreased appetite, and lethargy due to the discomfort caused by severe itching. Weight loss may occur due to the energy expended during persistent scratching. Generalized infections can lead to enlarged lymph nodes.
Localized scabies infection may occur when symptoms such as lesions, hair loss, and itching are confined to a specific region of the body. It’s crucial to note that sudden and severe itching, particularly in younger dogs, warrants investigation and treatment for scabies to prevent symptom exacerbation.
Causes
Sarcoptic mange spreads primarily through direct contact with an infected animal or human. These minuscule mites rely on a host for sustenance and do not persist in the environment for extended periods, remaining infective for up to 36 hours.
Transmission of scabies often occurs through close interactions between dogs, especially in areas frequented by infected dogs and foxes. Locations such as daycares, dog parks, shelters, and certain breeding facilities serve as breeding grounds for the spread of scabies among dogs.
It’s important to note that while scabies is not caused by poor hygiene, neglect or a weakened immune system can exacerbate its effects. Animals with compromised or developing immune systems, as well as those with underlying medical conditions, face a heightened risk of mange infestation.
Diagnosis
Veterinarians typically suspect sarcoptic mange in dogs experiencing a sudden onset of intense itching, hair loss, or scaling lesions, particularly in puppies and older, unwell dogs.
The most common method for diagnosing sarcoptic mange involves skin scraping and cytology. This non-invasive procedure entails using a scalpel blade to gently scrape the skin, causing mild irritation. The collected sample is then examined under a microscope, where the presence of mites confirms the diagnosis.
Identifying sarcoptic mites can be challenging, and multiple skin areas may require sampling for accurate identification. In cases where mites are not detected but clinical signs are severe, treatment may commence based on age and physical examination findings, with close monitoring of treatment response.
In some instances, mites may be detected through fecal flotation or fecal testing, as dogs may ingest them while licking or chewing their skin. Polymerase chain reaction (PCR) tests are available but may yield false negative results and are generally unnecessary when clinical signs and treatment response suffice for diagnosis.
When dogs do not respond to therapy or when other diagnostic methods prove inconclusive, veterinarians may consider performing a skin biopsy. Biopsy may be warranted in cases of draining wounds, skin swelling, or papules to rule out other potential causes and to confirm or exclude mite infestation.
Treatment
During the treatment of sarcoptic mange, it’s imperative to isolate your dog from other pets and limit contact with humans as much as possible to prevent both the spread of infection and potential reinfection. This isolation should persist until your veterinarian confirms that your pet is free of scabies.
Addressing any underlying systemic diseases or weakened immune system issues, as well as secondary skin infections, is crucial for dogs affected by scabies. Treatment failures often stem from neglecting to address secondary infections or ceasing medical therapy prematurely.
All cases of sarcoptic mange necessitate medical intervention. Several treatment options are available, including selamectin (Revolution), ivermectin, milbemycin (Interceptor), moxidectin, imidacloprid/moxidectin (Advantage Multi), lime-sulfur dips, doramectin, amitraz, fipronil (Frontline), fluralaner (Bravecto), afoxolaner (NexGard), and sarolaner (Simparica). If one treatment proves ineffective in resolving clinical signs, veterinarians may switch to another product to expedite recovery.
It’s essential to note that ivermectin should never be administered to collies, collie-crosses, Shetland Sheepdogs, Australian Shepherds, Old English Sheepdogs, and other dogs carrying the MDR1 gene, as they may experience severe and potentially fatal side effects. Safer alternatives should be utilized in these breeds.
Antibiotics may be prescribed to address skin infections, and anti-itch medications can provide relief from itching during miticidal therapy. Your veterinarian may recommend an Elizabethan collar (pet cone) if your dog is causing self-injury to the skin.
Environmental disinfection plays a crucial role in managing scabies cases. While the mites can perish in the environment, they can quickly reinfest hosts. Dogs diagnosed with or suspected of having scabies should have their collars, harnesses, bedding, crates, toys, and bowls washed with diluted bleach or replaced entirely. Infected items should be disposed of in sealed garbage bags away from animals and humans to prevent further infestation.
Recovery and Prevention
The recovery process from sarcoptic mange varies depending on the severity of the infection. Dogs with mild infestations typically experience quicker resolution compared to those with severe cases. In severe instances, it may take weeks to months for itching to subside completely and for the skin to commence healing.
To prevent re-infection with sarcoptic mange, it’s advisable to administer monthly or tri-monthly oral or topical flea/tick/mite preventatives. Additionally, maintaining a clean household environment is crucial in controlling scabies. Mange occurrences are less frequent in dogs that receive proper care, regular baths, and a balanced diet, and who sleep in clean bedding and crates that are cleaned frequently.
Sarcoptic Mange in Dogs FAQs
Is sarcoptic mange transmissible to humans?
Sarcoptic mange can be transmitted to humans. However, this form of scabies differs from human scabies. It often results in intensely itchy bumps within 24 hours of exposure, which may persist for up to 3 weeks. Since sarcoptic mites cannot complete their life cycle on human skin, they will eventually perish.
How can I determine if my dog has sarcoptic mange?
If your dog exhibits sudden and severe symptoms such as itching, hair loss, or scaling/crusted lesions, it’s crucial to promptly seek veterinary assistance for testing to confirm the presence of sarcoptic mange. During treatment, it’s important to limit their contact with other pets and humans until they have received appropriate treatment and the environment has been thoroughly disinfected.
How long is a dog contagious with sarcoptic mange?
A dog remains contagious with sarcoptic mange until 36 hours after initiating appropriate therapy and completing thorough environmental disinfection.