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Guide to the Diagnosis and Treatment of Vestibular Dysfunction in Dogs and Cats

Written by Debra Primovic | Aug 3, 2017 1:01:44 PM

Guide to the Diagnosis and Treatment of Vestibular Dysfunction in Dogs and Cats

Disorders of the vestibular system are commonly encountered in domestic species of dogs and cats.  Proper diagnosis is key to successful treatment, with most forms of vestibular disease being treatable.   Diagnosis can be aided by the history obtained from the client, as well as careful examination of the vestibular system. Diagnostic testing may further support and/or confirm a diagnosis, leading to definitive treatment options.

The ultimate goals of the clinician regarding vestibular dysfunction is to recognize the presence of a vestibular problem and attempt to classify the lesion as peripheral or central.

The following are signs seen with vestibular dysfunction:

Signs of Vestibular Disease in Dogs and Cats

Generic vestibular signs:

  • Ataxia
  • Head tilt
  • Pathologic nystagmus
  • Strabismus

Other signs:

  • Tachycardia
  • Ptyalism
  • Vomiting
  • Inappropriate urination/defecation

The following signs are typically seen with peripheral disease:

Peripheral – Unilateral:

  • Head tilt toward lesion
  • Pathologic jerk nystagmus
    • Positional or sustained – make sure to place patient on their back
    • Fast phase - directed away from the lesion
  • Asymmetric ataxia
  • Ipsilateral facial weakness
  • Strength preserved
  • Normal proprioception – Only in patients able to stand; you may have to wait 24 hours, then reassess

Peripheral – Bilateral:

  • Bilaterally wide head excursions (serpentine head movements)
  • Head tilt may be absent
  • +/- Nystagmus
  • Crouching posture
  • Bilateral facial weakness
  • Strength preserved
  • Normal proprioception – Only in patients able to stand; you may have to wait 24 hours, then reassess

Central disorders are those which involve vestibular structures located within the caudal fossa.  The most reliable indicator of central vestibular dysfunction are other neurologic deficits.

Central:

  • Delayed/absent postural reactions
  • Other cranial nerve deficits
  • Weakness
    • Not to be confused with imbalance

Paradoxical vestibular disease:

  • A unique central disorder
  • Head tilt and loss of balance opposite side of lesion
  • Nystagmus toward lesion
  • Side of lesion is determined by side of postural deficits, other CN deficits and/or hemiparesis

Table 1.  Comparison of peripheral and central vestibular signs/symptoms

Table 2.  Differential diagnoses for vestibular disease in dogs and cats

Congenital Disorders:

  • Vestibular disease
    • Clinical signs present at birth or when patient first walks
    • May improve/recover
  • Congenital Nystagmus:
    • Pendular
    • No fast phase: equal velocity to both sides
    • Benign
    • May spontaneously resolve

Additional Notes:

  • With time general proprioception and vision will compensate for balance
  • At night patients may be more vertiginous – leave a light on!
  • With acute onset, severe disease can be debilitating, but very often recoverable

Diagnosis of Vestibular Disease in Dogs and Cats

Clinical Approach to Diagnosis:

  • Is the patient displaying symptoms of vestibular dysfunction (seizures)?
  • Severely vertiginous patients may need sedation and time before examination
  • History is key! - Duration, progression, degree of imbalance

Diagnostics (as indicated):

  • Otoscopic examination – if possible
  • Oral examination – especially in cats
  • CBC
  • Biochemistry panel
  • T4/fT4
  • Clotting times
  • Urinalysis
  • Thoracic radiographs
  • Abdominal radiographs

Treatment of Vestibular Disease in Dogs and Cats

Therapeutic Options:

Sedation PRN:

Diazepam: 0.25-0.5 mg/kg  (q30 min x 2 doses, then CRI at 0.25 mg/kg/min)

Acepromazine: 0.01-0.2 mg/kg q4-6H prn (3 mg total dose)

Additional medications:

Maropitant: 1 mg/kg SQ q24h or 2 mg/kg PO q24h

Meclizine:

Dogs:   0 - 5kg       6.25 mg PO q8-24h

6 - 20kg  12.5 mg PO q8-24h

20kg+       25 mg PO q8-24h

Cats:                         6.25 mg PO q8-24h

Supportive care:

Hospitalization is always recommended for patients who are not drinking, as dehydration from sensible/insensible loss can be profound. Additional care may include:

  • Padded cage
  • IV Fluids
  • Music – “Through a dog’s ear”/quiet environment

Prognosis for Vestibular Disease

The severity of signs does not correlate to prognosis.Many patients will be significantly improved within 48 hours regardless of etiology (improvement may not be sustained).

  • Quite favorable as many causes are treatable/manageable
  • Recurrence is possible and dependent upon etiology
  • If a tumor is suspected, prognosis for 1-year survivability with good quality of life is fair
  • Central disease ≠ bad prognosis

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