Ear Mites in Dogs - Otodectes Cynotis

Have you noticed your dog is scratching his ears? Is he kicking at them vigorously with his back feet or trying to shake his head constantly? Yes? If this is accompanied by a thick black/brownish discharge in the ear, generally dry and forming crusts, then it is possible your dog is suffering from ear mites.

Learning to identify the signs of ear mites and understanding the lifecycle of the mite will allow you to quickly treat your dog to prevent further discomfort and prevent secondary infections occurring in addition to preventing this irritating condition spreading to other animals which your dog comes in to contact with.

What are ear mites?

Otodectes cynotis or the common ear mite is a parasite which lives in the ear canal of dogs , cats and other animals , they can migrate through the fur from ear to ear and may be found anywhere on the dogs body. Unlike other parasites they do not bite or suck blood instead they live off dead tissue and secretions from the skin. They live, walk and lay their eggs on the walls of the ear canal and in many cases are found in huge numbers hence the extreme irritation seen in the animals affected by these parasites. Ear mites are highly contagious; if you own more than one dog, or cats, then it is almost certain it will spread quickly between them.

Although not life threatening, Ear mites should never be left untreated. Excessive shaking of the ear can result in complications such as aural hematomas while some cases where infestations have been left or there is a large mite burden, otitis (inflammation of the ear) can develop. If not properly treated otitis can cause complications to the inner and middle ear and as such mites should be treated as soon as they are suspected.

The ear mite has a 21 day life cycle, this is important for the timing of treatment of the mites to ensure they are successfully eradicated.

Fig.1 Lifecycle of Otodectes cynotis – 21 days

Signs of ear mites:

The first sign that will usually alert you to the presence of ear mites is uncharacteristic irritation and scratching in your dog. The mites move around constantly within the ear canals though they are not limited to the ears and can migrate throughout the dog’s body. Your dog may not look unwell in himself but the sensation of the mites moving is extremely irritating and can result in any of these listed signs.

Signs may include:

• Generally agitated demeanour
• Scratching in and around the ears
• Thick, black/ brown crusty ear discharge
• Discharge may have an abnormal unpleasant odour
• Dragging the ears along carpets and floors or against furniture
• Shaking his head
• Restless
• Scratching base of tail, back and around neck and chest
• In severe cases you may notice hairloss around the ears and on the body
• Very occasionally they any become snappy due to the extreme irritation.

Diagnosing ear mites

If you suspect that your dog has ear mites, it is advisable to take him to your veterinary surgeon as soon as you can. The condition is extremely uncomfortable - imagine how it feels if a spider runs across your skin – well your dog has thousands of these mites running around in each ear! Using an otoscope – an instrument to view inside the ear canal – the mites can easily by seen by the naked eye of the vet or veterinary nurse as they will move towards the direction of the light on the otoscope. They appear as moving creamy coloured flecks and are usually seen in such large numbers they are unlikely to be missed. In the rare cases when they can’t be seen on initial examination, the diagnosis can be confirmed by viewing a swab from the ear under a microscope. It is vital that mites are diagnosed correctly as certain ear infections and conditions can show similar signs and it is important that the right treatment is prescribed for the right condition.

Treatment of ear mites

The type of treatment prescribed by your vet is dependent upon the severity of the infestation. If there is a secondary infection present then antibiotics will likely be prescribed alongside topical treatment. The treatment regime will normally consist of firstly cleaning the ear followed by application of a medicated agent to kill the mites. If the mites have spread to the rest of the body the dog will also require a flea product to be applied which is licensed for treating mites. Both cleaning the ears and applying medication will be necessary several times a day for the duration of the treatment period. The cleaning stage is vital as the ear canal must be free of any wax and debris as this will prevent penetration of the medication if left in the ear. Treatment usually lasts beyond the 21 day lifecycle which ensures all stages of hatching adults are caught and no further eggs are laid.

Prevention of ear mites

Maintaining good hygiene in your dog and its surroundings can help to prevent future infestations. Regularly washing your dog’s bedding and treating both this and any carpets and furnishings he sleeps on with a reputable flea treatment will kill any adult mites. It is advisable to ensure your dog’s ears are dried after bathing, going out in the rain or damp and regularly cleaned with a preparatory animal ear cleaner removing any excess wax. If you notice any usual discharge or any foreign objects in or around your dog’s ear then do not hesitate to consult your veterinary practice, it is not recommended that you attempt to treat ear mites without veterinary supervision particularly given the sensitivity of the aural canal.

Can ear mites be transmitted to humans?

Rarely. There are cases of ear mites infesting humans however these are few and far between.