& Management / Disease
Investigation & Management / Techniques:
||Based predominantly on the description
given by Mehler (2006). (B601.17.w17)
- Anaesthetise the rabbit. See: Treatment and Care
- Anaesthesia and Chemical Restraint - Lagomorph Anaesthesia
- Shave and aseptically prepare the area around the base of the ear.
- Transparent drapes may be placed around the surgical site.
- Place the rabbit in dorsal recumbency with support under the neck so
the neck can be extended.
- Use palpation to identify the angle of the caudal mandible, the
wings of the atlas, and the tympanic bulla.
- The tympanic bulla is found below the cartilaginous floor of the
external canal of the ear. (B615.8.w8)
- Make a skin incision from just caudal to the angle of the mandible
to just cranial to the wing of the atlas.
- Continue the incision through the subcutaneous tissue.
- Identify the digastricus muscle, hypoglossal muscle and hypoglossal
- Gently retract the hypoglossal nerve away from the surgical
- Bluntly dissect down to the ventral wall of the tympanic bulla.
- Keep directly over the bulla during the blunt dissection.
- Identify the tendon crossing over the ventral surface of the
bulla - entry into the bulla should take place medial to the
- Make a hole in the ventromedial aspect of the bulla using a
pneumatic burr or a small Steinmann pin. (B601.17.w17,
- Use small rongeurs to enlarge the hole on the ventromedial
aspect of the bulla.
- Take samples for bacterial culture, cytology and histopathology,
- Gently lavage the bulla using copious quantities of sterile fluid.
- Remove the inner epithelial lining of the bulla by careful scraping
with a bone curette.
- Removal of all the lining is important to avoid recurrence of
- Avoid the dorsomedial compartment of the bulla, to ensure
that the inner ear is not damaged during this process.
- Lavage the bulla.
- If required, implant a ventrally draining silicone tube drain. (B615.8.w8)
- Flush the drain daily for 3-5 days, then remove the tube. (B615.8.w8)
- An Elizabethan collar may be needed to avoid the rabbit
scratching out the tube. (B615.8.w8)
- Close the subcutaneous tissue.
- Close the skin.
- See: Treatment and Care
- Surgery - Post-operative care
- Initiate or continue analgesia, antibiotic treatment, anti-nausea
treatment and medical management of ileus. (B601.17.w17)
- Monitor for signs of: (B601.17.w17)
- Horner's syndrome
- Hypoglossal nerve defects.
- Increased head tilt.
- Progressive ileus.
|Appropriate Use (?)
- Otitis media associated with signs such as head tilt, opisthotonus,
horizontal nystagmus and anorexia (B600.12.w12)
which is not improving with medical treatment. (B601.17.w17)
- Neoplasia affecting the bulla. (B601.17.w17)
|Complications/ Limitations / Risk
- There is a high risk of post-operative complications. (J15.28.w1)
These may include:
- Horner's syndrome. (J15.28.w1)
- Hypoglossal nerve defects. (J15.28.w1)
- Increased head tilt. (J15.28.w1)
- Torticollis. (J15.28.w1)
- Progressive ileus. (J15.28.w1)
- Self-mutilation. (B601.17.w17)
- Cellulitis. (B601.17.w17)
|Equipment / Chemicals required and Suppliers
Standard anaesthetic equipment
Surgical equipment, including a pneumatic burr or a
small Steinmann pin, small rongeurs and a bone curette of appropriate
|Expertise level / Ease of Use
- This procedure should only be
carried out by an individual with appropriate clinical training and practical
|Cost / Availability
- Availability of an appropriately trained veterinary surgeon.
- Costs of anaesthesia and surgery.
The costs of a surgical operation include those associated with: (J15.30.w1)
- Pre-operative diagnostics (e.g. radiography, ultrasonography, blood
- Perioperative medication (e.g. analgesics, antibiotics, fluids).
- Surgical preparation (of the operating theatre and the patient,
including staff time).
- Consumables and equipment.
- Time of the surgeon and assistant(s).
- Post-operative hospitalisation.
|Legal and Ethical Considerations
In some countries there may be
legislation restricting the use of this type of technique to licensed veterinarians. For
example in the UK: "The Veterinary Surgeons Act 1966 (Section 19) provides,
subject to a number of exceptions, that only registered members of the Royal College of
Veterinary Surgeons may practice veterinary surgery." (See: LCofC1
- RCVS Guide to Professional Conduct 2000 - Treatment of
Animals by Non-Veterinary Surgeons).
||Debra Bourne MA VetMB PhD
Frances Harcourt-Brown BVSc