What are Mites?
Mites are tiny arachnids that are closely related to spiders and ticks. There are many different species of mites that can affect dogs. Mites have eight legs and oval-shaped bodies without any obvious segmentation. They range in size from 0.5-2.0 mm long and are often visible to the naked eye, especially when in large numbers.
There are three main types of mites that commonly infest dogs:
- Demodex mites – live in hair follicles and are species-specific to dogs. Demodex canis is the most common species.[1]
- Sarcoptes scabiei mites – burrow into skin and cause intense itching. They are contagious to other dogs and humans.[2]
- Otodectes cynotis mites – live in the ear canal and cause irritation.
The mite life cycle consists of egg, larva, nymph, and adult stages. The adult female mite lays eggs which hatch into larvae. The larvae develop into nymphs which then molt into adults. The entire life cycle can be completed in as little as two weeks for some species. Mites can rapidly reproduce under favorable conditions.
[1] https://www.pethonesty.com/blogs/blog/dog-mites
[2] https://nexgard.com.au/dog-parasites/mites/mites-on-dogs
Mites that Affect Dogs
There are several types of mites that commonly affect dogs:
Sarcoptic Mange Mites
Sarcoptic mange mites (Sarcoptes scabiei) burrow into the skin and cause severe itchiness and skin irritation. These mites are very contagious and can spread between dogs and even to humans. Sarcoptic mange causes hair loss, redness, papules, and crusting of the skin (Rodriguez-Vivas et al., 2003).
Ear Mites
Ear mites (Otodectes cynotis) live in the ear canal and cause itching, head shaking, and crusty/waxy buildup in the ears. Ear mites spread easily between dogs and cats. They can lead to secondary bacterial and yeast infections of the ears if left untreated.
Demodex Mites
Demodex mites (Demodex canis) live in hair follicles and usually don’t cause problems. However, in some dogs, excessive growth of demodex mites leads to hair loss, redness, scabbing, and skin infections, especially in puppies or dogs with weakened immune systems. Demodex mites are not contagious to other animals or humans.
Cheyletiella Mites
Cheyletiella mites (Cheyletiella yasguri) live on the skin surface and cause scaling, itching, and hair loss. These mites are highly contagious between dogs and cats, but don’t affect people. Heavy infestations can cause skin infections.
Transmission of Mites
Mites are easily transmitted between dogs through direct contact. When dogs play together, sleep near each other or groom one another, mites can spread from an infested dog’s skin and hair to a healthy dog (Merckvetmanual, 2023). Mites can also be transferred from a mother dog to her puppies.
While less common, mites can also spread through the environment. Bedding, kennels, grooming tools and other surfaces can harbor mites. If an infected dog has been in the area, mites can linger and then be picked up by another dog (Nexgardc, 2023).
To limit transmission, keeping infected dogs isolated until treated is recommended. Thoroughly washing bedding and disinfecting grooming tools and kennels is also important to remove any lingering mites.
Signs of Mites
The most common signs of mite infestation in dogs include:
- Intense itching – Mites cause severe itching as they feed on the skin, burrow, and lay eggs. Itching can develop even after mites have left the body.
- Hair loss – Mites lead to hair loss that may appear in patches or affect large areas. Hair loss often occurs around the ears, elbows, armpits, and chest.
- Redness and irritation – The skin becomes inflamed and reddened from mites burrowing and feeding. Papules and crusts may also develop.
- Crusting – Crusty sores and scabs can form where mites have fed on or irritated the skin.
- Ear inflammation – Mites like ear mites can cause inflammation and crusting of the outer ear.
The intense itching and discomfort of mange causes dogs to scratch, lick, and bite at their skin continuously. Secondary skin infections can develop from this self-trauma. Seeking prompt veterinary care is essential for treating mites and relieving a dog’s discomfort.
Risk Factors for Mites
Some dogs are at higher risk than others for developing mite infestations. Three major risk factors for mites in dogs are:
Young Dogs – Puppies less than 18-months old seem especially susceptible to mites like demodex [1]. Their immune systems are still developing, leaving them more vulnerable to skin parasites.
Dogs with Weakened Immune Systems – Dogs with health conditions like canine distemper virus, cancer, or autoimmune disorders are prone to mites [2]. Their compromised immune function cannot suppress mite overgrowth.
Shelter/Breeding Facility/Pet Store Dogs – Dogs from crowded living conditions like animal shelters, breeding facilities, and pet stores have increased exposure to mites. Close contact with other dogs facilitates mite transmission [3].
Knowing the risk factors can help identify dogs predisposed to mites for closer monitoring and prevention.
[1] https://www.pethonesty.com/blogs/blog/dog-mites
[2] https://bondvet.com/b/what-are-dog-mites
[3] https://www.merckvetmanual.com/dog-owners/skin-disorders-of-dogs/mite-infestation-mange,-acariasis,-scabies-in-dogs
Diagnosing Mites
To diagnose mites, veterinarians will perform a thorough physical exam of the dog. They will look closely at the skin for any abnormalities like redness, bumps, scabs, or hair loss that may indicate mites.
One of the main diagnostic tests for mites is skin scraping or tape prep. The veterinarian will use a scalpel or blade to gently scrape the affected areas of skin and collect skin cells and debris. This sample is placed on a slide and examined under a microscope to look for mites, eggs, or mite fecal material (Mite Infestation in Dogs – Merck Veterinary Manual).
Tape prep involves pressing a strip of clear tape to the affected skin, then sticking the tape to a slide for microscopic examination. This picks up any mites or eggs present on the skin surface (Spotting and Treating Dog Mites – Purina).
Skin scrapings and tape preps allow veterinarians to definitively diagnose mites by directly visualizing the mites, eggs, or fecal material under the microscope. This is the most accurate way to diagnose a mite infestation.
Treating Mites
There are several treatment options available for mites in dogs:
Medicated dips and shampoos containing ingredients like pyrethrins, permethrin, or amitraz can help kill mites on contact. These topical treatments often require repeat applications over several weeks to fully clear an infestation (Mites on dogs – Symptoms, Prevention & Treatment).
Oral medications like ivermectin, milbemycin, or moxidectin can systemically kill mites from the inside out. These medications are given daily or monthly, and treatment may need to continue for several months to eliminate mites (Mite Infestation (Mange, Acariasis, Scabies) in Dogs).
Topical medications like selamectin, fipronil, and amitraz are applied to the skin monthly to kill mites on contact and continue working over time. Repeat applications are often needed to fully clear an infestation.
Because mites can be difficult to completely eliminate, repeat treatments are often required over a span of weeks or months to ensure all life stages are killed and reinfestation does not occur.
Preventing Mites
There are several steps you can take to help prevent your dog from getting mites:
Avoid contact with infected dogs. Mites are very contagious, so limiting your dog’s exposure to dogs with mites can reduce their risk of infection (https://nexgard.com.au/dog-parasites/mites/mites-on-dogs). This includes keeping them away from stray dogs and not sharing brushes or bedding with infected dogs.
Promptly treat infected dogs. If your dog does get mites, treating them quickly can help prevent the mites from spreading and infecting other pets (https://wagwalking.com/wellness/how-to-prevent-your-dog-from-getting-mites). Follow your vet’s treatment recommendations diligently.
Clean your dog’s environment and bedding regularly. Mites can survive in bedding, carpets and kennels. Frequently wash your dog’s bedding and vacuum to remove mites and eggs (https://www.wondercide.com/blogs/news/mites-on-dogs).
Prognosis for Dogs with Mites
With prompt and proper treatment, the prognosis for dogs with mites is usually excellent.[1] Most dogs fully recover with no long-term effects once the mites have been eliminated and any secondary skin infections have been cleared up.
However, if mites go undiagnosed and untreated, they can spread and cause serious skin irritation, hair loss, infections, and other complications. Left untreated, certain mites like demodex can become very challenging to eliminate and may require aggressive treatment. This is why it’s important to have your dog examined and obtain an accurate diagnosis if you suspect mites.
Puppies and dogs with weakened immune systems may be prone to recurrent infections even after treatment. Your vet will advise on any necessary follow-up care and precautions to prevent reinfestation.
Overall, with veterinary guidance and proper at-home care, most dogs fully recover from mites and do not have any lasting effects if addressed promptly.
When to See a Vet
If you notice any signs of a potential mite infestation in your dog, it’s important to have them examined by a veterinarian. Some key signs that warrant a vet visit include:
- Skin irritation or inflammation – Mites can cause red, irritated skin that may appear scaly or have scabs.
- Hair loss – Certain mites like demodectic mange mites can cause patchy hair loss.
- Ear inflammation – Ear mites often lead to red, inflamed ears that may have a dark crumbly discharge.
- Itching or scratching – The presence of mites and their bites leads to intense itchiness. You may notice your dog scratching or biting at their skin constantly.
Since mites can spread quickly between animals, make an appointment with your vet as soon as you notice any symptoms. Leaving mite infestations untreated allows the parasites to multiply rapidly. Your vet can diagnose the presence of mites and recommend the best treatment to eliminate them and relieve your dog’s discomfort.