Mites in dogs

If your dog is constantly scratching, if his skin is flaky or full of sores or scabs and he's losing fur, this may be a sign of mites. These annoying skin parasites can make a dog's life miserable and, if left untreated, cause serious illness. Read here which mites infest dogs, and what to do if your dog has them.

How to tell if your dog has mites

Unlike fleas, most mite species are not visible to the naked eye. One exception are ticks, which are a type of mite.
First of all: no need to panic! Every dog gets mites, and most mites don't cause any problems. There are even some mites that live on human skin. However, certain types of mites are damaging to their host animal, because large populations of them can lead to severe skin lesions. Some mites can also be transmitted from dogs to people.

The signs of a mite infestation vary depending on the species. The most common symptoms are severe itch, hair loss, dandruff, sores, and scabs on the skin. The dog's constant scratching leads to bacterial secondary infections which make the symptoms worse.

A dog that scratches excessively should be examined by a vet to quickly determine if he has mites. The type of mite can be seen through microscopic examination of a skin scraping from an affected area. The sooner the dog is treated for mites, the better!

Where do mites come from?

There are many ways that these parasites can be transmitted, depending on the species.

• They may be passed to a dog from its mother. During nursing, skin contact and body warmth facilitate the transmission of mites from the mother to her pup.
• They can also be passed on when dogs play together, or when they sniff each other.
• Mites can also spread via contaminated brushes, rugs, dog baskets, transport boxes, etc.
• Wild animals, especially foxes, can transmit mites to dogs. There doesn't even have to be direct contact – it's enough if the dog snoops in or around the entrance to a foxhole.
• Certain mites spend their larval stages in grass and then attach themselves to passing dogs.

Mites can severely impair a dog's skin health and well-being. Mites normally pose no problems for healthy dogs. Their immune systems can inhibit the spread of parasites on the skin.
A mite infestation and associated skin problems may indicate a weak immune system!

Which mites can be hazardous for my dog?

Demodex canis

An infestation of Demodex canis (demodectic mange) is one of the ten most common causes of canine skin diseases. Demodex mite species are normally found on skin, including human skin. These cigar-shaped parasites are found in hair follicles and sebaceous glands, feeding off skin waste products. Their activity promotes the production of sebum, thus protecting the skin from outside environmental factors. However, in dogs with compromised immune systems or genetic immunodeficiencies, these mites can multiply unimpeded and cause demodicosis, a skin disease. Because Demodex canis mites are host-specific, humans are not at risk of contracting them.

They are most often transmitted from a mother dog to her pups. Skin lesions start to appear from the stress of weaning, and do not affect every pup. The affected areas are those that come in direct contact with the mother's teats: upper lip, nose, muzzle, ears. In mild infestations, hairless circles may form around the eyes. If the demodicosis remains local, isolated, round, inflamed areas form on the skin. These mostly heal on their own after six to eight weeks. Nevertheless, the dog should be monitored and examined by a veterinary surgeon!

Generalised demodicosis is more severe, with skin lesions spreading from the head to the neck, trunk, and limbs. Hair loss occurs and the skin forms pustules or papules. These skin lesions are accompanied by itching. The inflammation of the skin can cause the dog to have bacterial infections, ulcers, fevers, swollen lymph nodes, and weakness. Generalised demodicosis is often found in dogs between three and eighteen months of age. Although the mites have been present since infancy, the disease usually appears in the dog's second year. Adult-onset demodicosis is quite rare and usually the result of the immune system having been compromised through other illnesses or from certain medications.

Susceptibility to Demodex canis may also be connected with a genetic defect of the immune system. Some dog breeds are more prone to severe cases of demodicosis. A reduced immune response results in excessive mite reproduction. Particularly susceptible breeds include Pugs, American Staffordshire Terriers, Shar Peis, and West Highland White Terriers.

Pododemodicosis is a specific and quite unpleasant form of demodicosis on the dog's front paws. It affects very large breeds such as Great Danes, St. Bernards, Newfoundlands, and Old English Sheepdogs. Dogs with pododemodicosis suffer from intense itching and will lick their paws raw. This inevitably leads the paws to develop bacterial infections and results in lameness.

Sarcoptes scabiei

A Sarcoptes scabiei (itch mite) infestation is especially dangerous for dogs. These mites are contracted from foxes, but also from other dogs and cause the highly contagious sarcoptic mange, sometimes called "fox mange". The mites can survive up to 18 days in fallen flakes of skin without their host animal, which means that it isn't even necessary for the dog to have any direct contact with a fox. Mites can affect dogs of all ages. Hunting dogs are particularly at risk, but so are family pets that like to explore their surroundings or frequently play with other dogs. Even a small mite infestation can cause severe symptoms!

Itch mites burrow down to 1 cm in the skin and lay their eggs there. Changes to the skin will begin to appear on the head, mostly at the ends of the ears, the snout, and around the eyes. Mites also tend to prefer lightly haired areas like the underbelly, elbows, hocks and inside legs.
The mites' activity causes reactions which include scaling, nodules, pustules, and massive itching which worsens in warm environments. The dog's scratching and rubbing encourages further skin damage and bacterial secondary infections. In advanced stages the dog will have hair loss, scabs, and wrinkly skin. The skin lesions and itching cause constant stress for the dog, resulting in reduced performance, reduced food intake, and behavioural disorders. 

Itch mites can be easily transferred from dogs to humans. Humans can also become infected with mites from being in the contaminated environment of a dog. Humans will experience sores and itching on hands or other body parts that have come in direct contact with the dog, its bed, blanket, etc. Because humans are not viable hosts for Sarcoptes scabiei, these "pseudoscabies" symptoms disappear on their own after two or three weeks. 

Harvest mites

In some years, a massive appearance of larvae of the underground-dwelling harvest mite or chigger (Neotrombicula autumnalis) will occur in late summer and autumn. The larvae climb up plants in gardens, parks, and meadows and attach themselves to dogs, cats, horses, and even humans. They are predominantly active in late afternoons at temperatures above 16°C. The parasites suck on the tissue and blood of their hosts and fall away when they are full. They may be observed as tiny red dots on thin areas of the dog's skin, such as the paws, legs, nose, belly, between the toes, and around the eyes and lips. They cause severe itching, pustules, wheals and scabs, and major infestations can cause mange-like symptoms. Repeated infestations can cause the dog to have hypersensitivity reactions. In humans, harvest mites cause the severely itchy "chigger bites" – however, dog-to-human transmission does not occur.
Tip: Harvest mites can be easily identified by using a strip of clear adhesive tape. Gently press the strip to the affected area; the mite larvae will stick to the tape.

Ear mites

Otodectes cynotis colonise the external ear canal of one or both ears of the dog. Ear mites can be seen by the naked eye as moving white dots. They cause ear infections (Otitis externa) which are characterised by a very typical brown, greasy, curd-like secretion. Dogs can contract ear mites from other dogs, from cats, or from infested areas. The parasites can survive without a host for several weeks in humid conditions. Pups are more susceptible than adult dogs. Afflicted dogs suffer from severe itching and will frequently scratch their ears.

Cheyletiella yasguri
Cheyletiella yasguri (also known as walking dandruff) are actually a type of predator mite, which feeds on other arachnids. Some species of predator mite, however, also infest mammals and live from skin tissue and tissue fluid. Cheyletiella yasguri primarily spread in dog kennels and affect young or weak animals. The mites can be seen with the naked eye as "walking" flakes, especially on the dog's back, croup, and head. While some dogs can tolerate an infestation and hardly show any symptoms, others experience massive flaking and itching that worsens at night or in warm environments. Dogs with hypersensitivity to Cheyletiella yasguri develop scabs and lose fur. The mites are easily transmissible through direct contact or from infested dog brushes or combs. They can also be transmitted to humans but will not remain on human skin for more than short periods. 

Canine nasal mites, or Pneumonyssoides (Pneumonyssus) caninum are primarily found in Scandinavian countries and live only on dogs. Transmission likely occurs from dog to dog, or indirectly from rugs and transport boxes. Canine nasal mites are quite resilient and can survive for long periods in the dog's environment. The parasites take hold in the dog's nose and sinuses and can cause sneezing, nasal itching, breathing difficulties and impaired sense of smell. The dog will have sneezing fits; these and the subsequent intake of air can sound dangerous, as if the dog is unable to breathe. Diagnosis is difficult and there is no known treatment.

Mites in the dog's environment

Mites not living on or in the dog's skin can also cause problems, including house dust mites, which are primarily found in living areas. More and more dogs are developing allergic reactions to the excretions of over 200 mite species that live in house dust and feed on dander. Symptoms vary and range from constant itching to allergic skin inflammations.
Storage mites live in nutrient-rich environments, for example in grains or feeds. They require a humidity of over 55%, otherwise they become desiccated. They can be recognised as mite dust on the bottom of the dog food packaging. Infested dog food will sometimes have a minty smell. Storage mites often appear when the food is stored for too long, or they may also be found in house dust. A dog with an allergy to storage mite excretions will show severe itching.

What should I do if my dog has mites?

A dog that is constantly itching must be examined by a vet! If an examination and/or a skin scraping determine a mite infestation, there are chemical preparations – spot-on treatments, collars, tablets – that will kill off the mites and bring quick relief to your dog.

Caution: If there are any other dogs or pets in the same household, these must be treated as well! Never treat cats on your own, as mite applications intended for dogs can be quite harmful for cats! Some miniature dog breeds also have strong reactions to mite-killing substances. Always consult with your vet before treating your animal for mites!   

After a treatment, you can bring your dog's metabolism back on track with herbs so that harmful substances are quickly eliminated. Milk thistle and artichoke promote liver metabolism and support the liver's detoxification function. Goldenrod and dandelion stimulate kidney function. Through their slight diuretic effects, they increase urine production and promote the flushing of contaminant substances.

Natural substances can eliminate mites temporarily, but their effectiveness is limited. Some dog owners swear by ferns placed in their dogs' beds or doghouses to repel parasites. Tee tree oil is often recommended as a cure-all against ectoparasites, but is harmful to dogs in large doses. High-concentrate essential oils like lavender, citronella or mint are said to repel pests but will also bother your dog's sensitive nose! Onion and garlic extracts, which are said to cause perspiration that is unpleasant for parasites, are toxic for dogs!

Caution: Never apply undiluted essential oils to a dog's skin, as these will irritate the skin and mucous membranes! Even when using diluted essential oils, the dog must be prevented from licking the treated areas! Using essential oils should only be done in consultation with your vet or aromatherapist, as there are many essential oils that can be poisonous for animals. Always follow the manufacturer's instructions.

Tip: If you discover harvest mite(chigger) larvae on your dog after a walk, wash your dog with curd soap to kill the mites.
Caution: Rinse well! Soap residue on the skin can cause itching!

Treat dry, flaky, itchy areas with local preparations to promote healing. The anti-inflammatory properties in camomile, calendula and mallow tea have anti-inflammatory properties and soothe irritated skin. Use the lukewarm tea to gently remove flakes and scabs.

Post-treatment with a moisturising, nourishing herbal cream will soothe the dog's irritated skin. Herbs like lavender, pansy and speedwell help to relieve skin inflammation and itching. Oak extracts speed sloughing in minor skin wounds and prevent the skin from being colonised by harmful bacteria.

However, the dog's environment must also be rid of mites: Wash dog rugs, cushions and beds at minimum 60°C! Brushes, collars, harnesses, toys – all objects that regularly have contact with the dog's skin – must be washed in hot water.

Tip: Place non-washable pillows and stuffed animals in the freezer for 48 hours. Temperatures below 12°C will kill off mites.

What can I do to prevent mite infestations?

Mites live all around us. We just don't see them. You can't protect your dog from ever coming into contact with mites!
Not every scratch is a sign of a mite infestation! If your dog has been scratching for longer than usual, consult with your vet as soon as possible. In the meantime, you can do the following:

• Check your dog's skin for the presence of mites and lesions – don't forget the paws and ears!
• Keep your dog's environment clean and wash blankets regularly.
• If your garden has harvest mites, keep grass mowed short and remove grass cuttings.
• If your dog has sensitive skin, there are changes you can make to feed to strengthen the skin barrier. Feed supplements containing vitamin E, such as linseed oil, promote skin regeneration.
• Spot-on treatments from your vet will protect your dog from Sarcoptes scabiei infestations. If your dog comes into contact with wild animals, either directly or indirectly, perhaps from a fox in your garden at night, there are preventive treatments to prevent mite infestations.

The best way to prevent mite infestations and associated skin problems is with a strong immune system! Dogs with weak immune systems – old or very young dogs, dogs with pre-existing conditions or stress – are susceptible to mite infestations! You can strengthen your dog's immune system with a variety of herbs:

• Echinacea stimulates the body's defences and blocks inflammatory messengers. Echinacea can increase the number of T-helper cells which control the function of various immune cells. Echinacea has strong immunostimulant properties and should therefore not be administered to animals with autoimmune diseases or immunodeficiencies.
• Sea-buckthorn and rose hips contain vitamins and trace elements. They are high in vitamin C, which boosts immune system function and protects cells from antioxidant stress.
• Siberian ginseng is a traditional herb used to treat physical weakness. It has antioxidant effects and increases the organism's adaptability to stress.
• Hawthorn fortifies the heart and promotes blood circulation.
• You can also support your dog's immune system by supplementing the feed with microalgae. Spirulina algae improves skin metabolism and helps to alleviate skin irritations.

A strong immune system inhibits the spread and reproduction of mites and can prevent the symptoms of a mite infestation!

Sources

• https://www.vtg-tiergesundheit.de (23.03.2021)
• https://parasitenportal.de (23.03.2021)
• https://www.pestium.de/ (22.03.2021)
• https://www.bft-online.de/kleintiergesundheit/2015/milben/hintergrundinformationen-milben (22.03.2021)