Head Tilt in Dogs (Vestibular Signs)

Overview of Head Tilt in Dogs (Vestibular Signs)

A head tilt is a persistent tilt or turn of the head along the animal’s central axis to one side or the other and is usually described according to the side of the head that turns down. A head tilt usually indicates vestibular signs that may be a problem in the animal’s middle or inner ear.

There are many causes for head tilt. Some of these include:

• Ear infections or mites
• Idiopathic (unknown cause)
• Foreign bodies such as grass seeds
• Head trauma
• Ototoxic drugs (drugs that are toxic to the ear)
• Punctured ear drum
• Hypothyroidism (underactive thyroid)
• Encephalitis (inflammation of the brain)
• Cancer

What to Watch For

• A tilt of your pet’s head to one side or the other
• Redness or pain associated with the ear
• Falling, circling, or rolling (usually toward the direction of the head tilt)
• Nausea due to vertigo
• Vomiting
• Lack of appetite
• Pain associated with chewing or opening the mouth.

Diagnosis of Head Tilts in Dogs

A head tilt is a symptom of a potentially serious medical condition. The cause of the head tilt should be investigated thoroughly by your veterinarian. Your veterinarian may investigate your pet’s head with a variety of means, which may include:

• A complete medical history
• A complete physical examination
• Neurologic evaluation
• Blood and urine tests
• X-rays of the head
• CT scan or MRI of the head
• Brainstem auditory evoked response (BAER) test
• Spinal (or cerebrospinal) tap

Treatment of Head Tilt in Dogs

Treatment of a head tilt is primarily supportive until a definitive cause can be identified. Supportive treatment can include:

• Intravenous fluids, especially if the pet is vomiting from nausea
• Antiemetics
• Antivertigo medications
• Topical ear medications
• Injectable or oral antibiotics

Home Care

If your pet is falling or rolling, protect him from objects such as furniture and stairs. Your pet may need assistance with walking or require being carried. Always support your pet, especially the head. If your pet has a head tilt, be careful and assist with descending and ascending stairs.

In-depth Information on Canine Head Tilts

Vestibular signs, a disturbance of our sense of balance, can be seen as a head tilt as well as other alarming signs such as falling, rolling, continuous circling and nystagmus (rhythmical, jerky movements of the eyes). Other signs of vestibular disease include nausea, vomiting and lack of appetite.

The vestibular apparatus in the inner ear maintains our sense of balance. It is a delicate sense organ that is completely surrounded by an extremely hard bone (petrous temporal bone) at the base of the skull. The inner ear has intimate connection with the brain via the auditory and vestibular nerves. The inner ear is also associated with the middle and external ear.

Since the inner ear is intimately associated with the middle and external ear, signs associated with ear infections such as malodorous discharge from the ear, scratching or shaking the ear and pain or redness of the ear may be seen.

A head tilt is usually described according to the side of the animal’s head that turns down. Animals typically fall or roll towards the same direction as the head tilt. Nystagmus (an involuntary rhythmic movement of the eye) is only a symptom of vestibular disease and does not indicate severity of the disease.

Since the middle and inner ear are located close to the temporal mandibular joint (jaw), there may be pain associated with chewing or opening the mouth. These animals may even yelp out in pain while they are yawning.

Causes of Head Tilts in Dogs

The most common cause of vestibular signs is ear infections. Damage to the inner ear structures or the brain itself may cause vestibular signs. Vestibular signs indicate either a problem in your pet’s inner ear or brain. It is very important for your veterinarian to determine quickly whether the cause of your pet’s vestibular signs are due to disease of the inner ear (peripheral vestibular disease) or to disease of the brain (central vestibular disease). The choice of different diagnostic tools and the prognosis depend on the suspected location of the problem. In general, peripheral vestibular disease has a better prognosis than central vestibular disease.

There are many causes for head tilt. Some of these include:

• Otitis media-interna. Infection of the middle or inner ear caused by bacteria, mites or even foreign bodies such as grass seeds is the most common cause for vestibular signs. Infections may initially affect only the outer ear, but if this inflammation ascends into the middle and inner ear, vestibular signs may be seen.
• Idiopathic (unknown cause). In older dogs this is the second most common cause of peripheral vestibular signs. This disease (Geriatric Canine Idiopathic Vestibular Syndrome) can cause catastrophic vestibular signs acutely. The dog may have problems walking and standing, and may also experience nystagmus and vomiting. Pets can improve with little treatment, although other causes such as ear infections and brain tumors should be ruled out.
• Ototoxic drugs can damage the ear resulting in vestibular disease. Not all animals have trouble with these particular drugs and medications; some of the most common ear medications contain some of these drugs. If your animal is being treated with one of these medications, it may be due to the administration of the drug. To determine if your pet’s symptoms are caused by the drugs, contact your veterinarian and discuss this possibility. The list of potential ototoxic agents include:

Antibiotics such as gentamycin, streptomycin, amikacin, neomycin, kanamycin, erythromycin, chloramphinocol, polymyxin B or metronidazole.

Some ear cleaners including ethanol (alcohol), chlorhexidine, idodine containing medications, centrimide and benalkonium chloride.

Diuretics such as furosemide, ethancrynic acid and bumetanide.

Antineoplastic (cancer fighting) medications such as nitrosoureas (CCNU and BCNU) and cisplatin.

Some of these drugs can also cause deafness.

Other causes of head tilt include:

• Head trauma can cause vestibular signs that may resolve with time.
• Endocrine diseases such as hypothyoidism can cause vestibular signs.
• Encephalitis affecting the area of the brain responsible for maintaining the sense of balance can cause vestibular signs. Some of the inflammatory causes for vestibular signs include canine distemper virus, Rocky Mountain spotted fever, ehrlichiosis, cryptococcosis, blastomycosis, coccidiomycosis, toxoplasmosis, neosporosis and granulomatous meningoencephalomyelitis.
• Neoplasia (cancer or tumors) in older pets affecting either the ear or brain can cause vestibular signs. Some tumors can be removed successfully after diagnosis using CT or MRI.

Diagnosis In-depth

A head tilt is a symptom of a potentially serious medical condition. The cause of the head tilt should be investigated thoroughly by your veterinarian. Diagnostic tests are needed to determine the presence of an underlying disease or cause for the head tilt. Your veterinarian may investigate your pet’s head with a variety of means, including a complete medical history. Be able to answer the following questions:

• When did the symptoms first occur?
• Was it a gradual onset or did your pet suddenly have the head tilt?
• Has a similar episode occurred?
• Does your pet have a disease that could be contributing to the symptom such as long-standing ear infections, hearing loss or deafness, or metabolic diseases such as heart disease or diabetes?
• Is your pet on any medicines?
• Is there any potential for exposure to toxic substances?

Additional tests may include:

• A complete physical examination including an otoscopic exam (looking into the ear canal) will help to determine if an ear infection could be causing the head tilt. The ear canal and tympanic membrane can be examined with an otoscope for ear wax accumulation, foreign bodies, infections or inflammation
• Cultures of ear discharge may be taken to help determine the best antibiotic to use in cases of ear infections
• A neurologic evaluation will be needed to determine if the head tilt and any other signs are due to peripheral vestibular disease or central vestibular disease. This evaluation will help guide your veterinarian to the appropriate tests needed to determine quickly what is causing the head tilt, and more importantly, what is the best treatment for the signs
• Laboratory work such as a complete blood count, serum chemistry analysis, and urinalysis will help to detect other conditions your pet may have that can contribute to the disease. As anesthesia is needed for some of the more advanced tests, baseline laboratory work may be needed to assess your pet’s health
• Blood screening tests for endocrine dysfunction such as hypothyroidism
• Measurement of blood pressure

Tests listed below may require general anesthesia. In general, modern veterinary anesthesia is very safe and well tolerated by pets. However, animals with vestibular dysfunction may show worse signs after waking up from anesthesia. The more severe signs usually resolve over 48 to 96 hours.

• Bulla radiograph series (X-rays of the skull) are needed to determine if there is significant disease in the middle ear as well as the inner ear. This test examines the normally fluid filled bulla or middle ear. Middle ear disease is the most common cause of head tilt and severe disease may need to be surgically treated. Anesthesia is required for diagnostic bulla radiograph series.
• CT (computed tomography) scan or MRI (magnetic resonance imaging) of the head are more sensitive tests than bulla series for detecting middle ear disease. Although both CT and MRI tests can detect disease in the brain, MRI is more sensitive than CT. These tests require anesthesia and may require referral to a specialist.
• Brainstem auditory evoked response (BAER) test may be needed to assess associated damage to hearing and the brainstem. Sound is transmitted to your pet’s ears and the brainstem electrical responses are recorded on a special machine called an electrodiagnostic machine. These tests require specialized equipment, which may require referral to a specialist.
• Cerebrospinal (spinal) tap is needed to determine if there is disease within the brain. This test allows examination of the cerebrospinal fluid (fluid that surrounds the brain and spinal cord). Abnormalities detected in the cerebrospinal fluid indicate severe disease that may require special medications. This test requires anesthesia and may require referral to a specialist.

Therapy In-depth

Your veterinarian may recommend one or more of the diagnostic tests described above. In the meantime, treatment of the symptoms might be needed, especially if the problem is severe. The following symptomatic treatments may be applicable to some but not all pets with vestibular signs. These treatments may reduce severity of symptoms or provide relief for your pet. However, nonspecific therapy is not a substitute for definitive treatment of the underlying disease responsible for your pet’s condition.

• If nausea is causing your pet to vomit or refuse food, your veterinarian may use intravenous or subcutaneous fluids to prevent dehydration.
• Antiemetic drugs usually act on the area of the brain that is involved in the vomiting reflex. These medications may be given by injection if your pet is vomiting or refusing food.
• Antivertigo medications can decrease the vestibular signs but should not be used long term. One medication commonly used is called Meclizine.
• If otitis is causing your pet’s vestibular signs, your veterinarian may prescribe an oral and topical antibiotic based on clinical judgment while awaiting results of the culture and sensitivity.