Head tilt in rabbits is common and can be caused by a variety of diseases. The correct medical term is vestibular disease. Another term that is often used is “torticollis” which means that the neck muscles are contracted. This does not occur in all rabbits with vestibular disease. Therefore, the term “torticollis” is not the best term to use for the cause of head tilt because it is a potential consequence of the disease. These rabbits can fall over, circle, have difficulties standing and develop eye injuries because the prominent eye globe is prone to trauma. The classic signs of true vestibular disease are a persistent head tilt and a loss of balance.
Diseases Resulting In Head Tilt
A major differentiation that has to be made when diagnosing the cause of head tilts is whether it is peripheral or central. Once this differentiation is made, the veterinarian can then proceed along a further course of diagnostics and treatment. In general, the prognosis for full recovery is better for peripheral disease than for central disease, but each rabbit is unique and treatment must be determined on an individual basis.
OTITIS INTERNA (Inflammation of the inner ear)
This is the most common cause of head tilt in the house rabbit. Causes of inflammation of the inner ear can include the following:
- Infectious disease
- Foreign bodies
The most accurate way to diagnose otitis interna is via a CT scan or MRI.
Treatment for otitis interna depends on the primary cause, but since the majority of head tilts in rabbits are likely caused by bacterial otitis interna, it is advantageous to use a long term course of antibiotics (3 to 6 weeks and up to several months)
OTITIS MEDIA (Inflammation of the middle ear)
This is also a common disease of rabbits and may occur along with or even be the cause of otitis interna. However, disease in this area alone does not cause a persistent head tilt.
Diagnosis and treatment are generally the same as listed for otitis interna. If the middle ear is affected, then significant pain may be present and may interfere with appetite. A pain medication with anti-inflammatory properties should be used.
BRAIN STEM DISEASE
- Infectious disease
- Protozoal disease
- Parasitic disease
- Cerebrovascular accident (stroke)
- Metabolic disease – This would be any disease, such as liver or kidney disease or gastrointestinal disease that leads to a buildup of toxins in the body due to malfunctioning of that particular organ. The toxins eventually affect brain function and may lead to some of the signs of weakness, loss of balance, etc.
- Heat Stroke
Diagnostic Approach to Head Tilt
- PHYSICAL EXAM
- BLOOD TESTS
- Complete Blood Cell Count
- Serum biochemistries
- Serology for E. cuniculi
These tests are of limited use in definitively diagnosing active disease. Most rabbits will be positive for E. cuniculi antibodies in the complete absence of any clinical infection by this organism. For this reason, interpreting a positive test is often difficult and complicated by the lack of credible scientific research into the organism and its relationship to the normal and the sick rabbit.
- BACTERIAL CULTURES
- RADIOGRAPHS (X-rays) CSF (Cerebrospinal fluid) Analysis – This may be useful if central disease such as encephalitis is suspected.
- BIOPSY – If it is possible to obtain a sample of the affected tissue, then a microscopic analysis can be extremely helpful in making a diagnosis.
- CT SCAN OR MRI
Treatment and Nursing Care
This will be determined once a diagnosis or rule out list has been developed.
The prognosis for recovery from vestibular disease is variable, depending on the cause. For most rabbits with peripheral disease, the prognosis is good to guarded and the vast majority will recover most of their normal head position and lead normal lives. This process may take weeks to months, however.