Why Is My Dog Shaking His Head?
Head shaking- what does it mean?
Head shaking in dogs is a common presenting problem for veterinarians. Most dogs will shake their heads in response to pain or irritation affecting one or both ears. There are several potential causes which can affect either the external ear flap (pinna) or the internal canals of the ears. It is important to identify and correct whatever the problem happens to be, as untreated ear disease will cause irreversible changes to the anatomy of the ear, making future problems more likely and more severe.
Parasites of the dog's ear
There are a range of common parasites which may cause inflammation of your dog's ears. The two most commonly encountered are ear mites (Otodectes), which infest the ear canals, and fleas (Ctenocephalides canis/felis), which irritate the pinnae or ear flaps. While ear mites are unlikely to cause any skin problems elsewhere, dogs with flea infestations will usually demonstrate more widespread itching, and potentially scaling and crusting of the skin along the back. Fleas will also be visible on a flea com or against light coloured hair coats.
Ear mite infestation may be diagnosed by your veterinarian on otoscopic examination of the ears. These parasites are tiny, and not usually visible to the naked eye. However, they cause an accumulation of characteristic dry, flakey wax in the dog's ears which may be obvious when you yourself examine them.
Less commonly, pet dogs may be affected by sarcoptic mange. The early stages of the infestation may be most severe around the pinnae, although the problem very quickly spreads to the rest of the body, causing diffuse itching, hair loss, and scabbing.
All of these infestations can potentially cause skin disease in pet owners, but are usually self limiting in individuals in good health.
Appearance of fleas on a dog
Foreign bodies in the ear
Occasionally, a foreign body such as a grass awn may become lodged in a dog's ear. The irritation this causes is usually severe, and begins very suddenly. It is not uncommon for a dog with a foreign body to require sedation or anaesthesia to allow a veterinarian to identify and remove the problem. Dogs with 'floppy' ears and those that run through thick undergrowth are most at risk of developing this problem.
Allergic ear problems in dogs
Allergic skin disease is an incredibly common cause of ear disease in pets, particularly dogs. In much the same way as in human medicine, allergies in pets are becoming an ever more common complaint in veterinary practice. This presents difficulties both in diagnosis and management of these patients. Allergic ear disease is likely at best to be recurrent, and at worst may require lifelong medication. Your dog's head shaking may or may not be part of more generalised itch and skin irritation.
The range of potential allergy-causing agents is endless, and the pet may often be allergic to more than one allergen. For example, many dogs with an allergy to house dust mites may also be allergic to fleas. Of all the types of allergies we identify, food allergy is the 'easiest' to deal with, because we do at least have control of most of what our pets eat, and by identifying and eliminating the culprit from the diet (commonly proteins such as chicken/beef/gluten) we can hope to control the pet's symptoms.
If your dog has a skin allergy, the head-shaking will usually have gradually worsened to the point where you realise there is a problem, although sudden flare-ups can occur (see below) with particular types of bacteria colonising the damaged ear canal.
Ear infections in dogs
Ear infections in dogs are rarely a primary problem. They usually occur as a result of inflammation or damage to the ear canal caused by parasites, foreign bodies or skin allergies as descried above. Anatomical defects such as may occur with scarring from previous ear problems may impair ventilation and drainage of the ear and can also predispose to infection.
Infection may be due to yeasts, most often Malessezia species, or bacteria such as Staphylococcus pseudointermedius. Both of these groups are normal inhabitants of the dogs's ear canal which proliferate when the skin's normal defenses are damaged. More severe infections with coliform (faecal) bacteria or Pseudomonas species results in more severe signs, may be more sudden in onset, and are commonly resistant to many first-line antibiotics. In these cases laboratory culture and sensitivity testing is an important step in the veterinary diagnostic investigation to ensure the correct treatment is chosen.
Treatments for ear problems in dogs
The choice of treatment for your dog's ear condition will obviously depend on his underlying problem. Many readily available over the counter products are available for treating parasitic infestations. Consultation with a veterinarian competent or specialising in dermatology is essential for managing many of the other conditions discussed above, as incorrect or inappropriate treatments can genuinely cause harm to the sensitive ear canal. In my daily practice I commonly encounter animals which have become permanently deaf as a result of owners administrating ear drops to ears with perforated ear drums. Only otoscopic examination of your dog's ears can confirm the presence of an intact eardrum, and the safety of administrating topical treatments. Otoscopy is simply the process of inserting a light source with a small 'nozzle' into the ear to allow magnification of the ear canal and any ojects such as ear mites within it. It is usually quite painless, although if your dog has a severely inflamed and painful ear, he may need to be sedated for the procedure.
What your veterinarian sees with the otoscope
Complications of ear disease
If not managed correctly, ear infection and inflammation can lead on to a number of problems. In the short term an aural haematoma may develop. This occurs when severe head shaking or scratching of the pinna causes rupture of a blood vessel under the skin of the ear flap. Blood then accumulates under the skin, causing the pinna to swell dramatically. This accumulation of blood needs to be drained by your vet to relieve pain and discomfort. Recurrent haematomas or those that are not drained will cause a 'cauliflower ear' to develop as a result of scarring.
Rupture of the tympanic membrane (ear drum) is commonly seen in infected ears. The membrane will regrow quickly in the ear once the inciting problem is settled, but as long as it is not intact it makes a middle ear infection more likely, and makes it unsafe to use topical medications within the ear itself.
Middle ear infection involves the bony area at the base of the ear normally protected by the ear drum. Signs of middle ear disease may be similar to those involving the ear canals, but also include a loss of balance, deafness, and possibly facial nerve paralysis. Successful treatment of middle ear infection may be challenging, and can require months of antibiotic treatment.
Regular ear cleaning helps prevent infections and parasite infestations
Epi-otic is a good quality antiseptic cleansing solution suitable for routine cleaning of your dog's ear.