||This procedure is described
for the treatment of bears which have been on bear bile farms and have had
surgery for the collection of bile by a surgically implanted catheter or
"free-dripping" fistula. This description has been provided by
Animals Asia Foundation veterinarians, based on their extensive experience
with this operation in bears rescued from bear bile farms.
NOTE: Although the procedure is described
below as accurately as possible, this is NOT a substitute for learning the
procedure by watching and assisting a veterinarian who is already
experienced in the technique.
Anaesthesia, analgesia and maintenance
[Editor's note: the following anaesthesia and analgesia regime
is the one followed at Animals Asia Foundation, where this operation has
been carried out on hundreds of bears.]
- Anaesthetise the bear using an initial dose (for non-stressed bears)
1 mg/kg Zoletil (tiletamine-zolazepam)
plus 0.01 mg/kg medetomidine (reconstitute Zoletil-100 with 5 mL medetomidine 1 mg/mL
to give 100 mg/mL tiletamine/zolazepam and 1 mg/mL medetomidine).
- With stress or disturbance the dose needs to be increased.
- If necessary, given an additional dose, based on the bear's
state of sedation, to a maximum of 3 mL/100 kg of the medetomidine/tiletamine/zolazepam
- Do not remove the bear from its cage until the palpebral
reflexes and tongue withdrawal reflexes are absent.
- Maintain on isoflurane at a flow rate of 1-2% (or higher if
required). Halothane has been used also.
- Give carprofen, 3.2 mg/kg subcutaneously as soon as the bear has
- Give enrofloxacin, 5.0 mg/kg subcutaneously before starting the
- Give butorphanol, 0.075 mg/kg intramuscularly into the pectoral
muscles 20 minutes before the onset of surgery then hourly during
surgery. Or give morphine, 0.1 - 0.5 mg/kg intramuscularly or
intravenously every 2-4 hours.
- An apparent excitatory response to morphine has been seen in one
- Place an intravenous catheter into a cephalic or saphenous vein.
- During anaesthesia, give warmed lactated Ringer's solution at a rate to maintain PCV. PCV and urine specific gravity are measured every hour; PCV is generally between 40% and 50%. Roughly, a 3 or 4 hour surgery requires about 4 liters of fluids in an average (100 to 150 kg) bear.
- In cold ambient temperatures, keep the bear warm, e.g. with an
electric heater beneath the operating table and hot water bottles
along the bear's flanks (also useful for maintaining the bear's
- In warm ambient temperatures, place cold water bottles along the
bear's flanks (also useful for maintaining the bear's position).
- Clip and shave the bear's abdomen around the surgical site.
- Monitor and record the bear's rectal temperature every 30 minutes
- Monitor and record the bear's heart rate, respiratory rate, pCO2
and oxygen saturation every five minutes.
- Monitor and record the bear's blood pressure every 10 minutes.
- Further information on anaesthesia and monitoring are provided in
Treatment and Care -
- Make an elliptical incision in the skin around the bile duct
- The length and width of the incision is determined from the size
of the mass palpated beneath the fistula and visualised
- There is often a large mass of fibrotic tissue and old abscesses
surrounding the gall bladder.
- If there is an associated hernia, the incision must be sufficiently
large to allow repair of the hernia,
- Bluntly dissect through the subcutaneous tissues to the abdominal
- Depending on the degree of inflammation and infection, the
tissues may be extremely vascular.
- Control bleeding with radio cautery and by ligation of vessels.
- Note there are often abscesses in the subcutaneous tissues,
commonly associated with old suture material.
- Enter the peritoneal cavity at a point caudal to the fistula.
- Note that in bears with a fistula the gall bladder is just below
the abdominal surface, attached to the fistula.
- Take care to avoid both the gall bladder and its surrounding
mass of tissue while entering the abdominal cavity.
- Make the opening large enough for the surgeon to insert a hand into
the abdomen and locate the gall bladder manually.
- Once the position of the gall bladder is determined, carefully
transect the abdominal muscles around the gall bladder.
- Constantly refer to the underlying mass of the gall bladder and
- An assistant holds the fistula and its surrounding island of
skin and muscle using an Allis tissue forcep.
- NOTE: At the cranial end of the incision, which often abuts
the rib cage, usually off-centre, take care to identify and avoid the
large blood vessels in this area.
- Once the gall bladder and associated mass are isolated in the centre
of the aperture, dissect away the mesentery, omentum and other
connecting tissues away from the mass, deep into the abdominal cavity,
to several centimetres along the cystic duct.
- Carefully examine the gall bladder, particularly at the fundus
end where it is attached to the fistula, for areas of weakness or
- At the cranial end of the incision it is common to find that the
mass of tissue or an abscess has grown into a liver lobe and needs
to be trimmed away.
- The normal band of tissue connecting the small accessory lobe of
the liver to the gall bladder needs to be transected.
- Note: the tissues surrounding the gall bladder are very
vascular. Careful dissection is required, with ligation of the
numerous blood vessels.
- Once the gall bladder and as much as possible of the cystic duct
have been freed, place two bowel clamps across the cystic duct, as
deep as possible, and proximal to another clamp which will be removed
with the gall bladder.
- Place two Allis tissue forceps on either side of the cystic duct,
proximal to the most proximal of the bowel clamps, to provide
additional security to the stump of the duct until it is ready to be
- Have the surgical assistant hold the Allis forceps.
- Transect the cystic duct between the two distal clamps (leaving the two bowel clamps attached to the stump) and the distal section with the gall bladder,
remove the gall bladder and distal duct.
- If gall stones or "sand" has been palpated inside the gall
bladder and duct, flush the duct by inserting a 16-gauge intravenous
catheter into the open end of the cystic duct, carefully loosening one
bowel clamp at a time to let the catheter through, and flush 20-60 mL
of sterile saline through the remaining cystic duct into the duodenum.
- Ligate the blood vessels running along either side of the cystic
duct with 3-0 Vicryl.
- Suture the open end of the cut stump in two layers, using 3-0 Vicryl,
in first a horizontal then a vertical inverting suture pattern.
- Once the surgeon is satisfied with the closure of the stump, release
- Make a tactile exploration of the abdominal cavity to locate any
foreign objects, abscesses or organ abnormalities.
- Flush the abdominal cavity with one litre of warm sterile saline.
- Infuse 1 000 000 IU Penicillin G, suspended in
5 mL of sterile water, into the
- Close the abdominal cavity in three layers:
- Close the muscle layer with a cruciate pattern using 0-0 or 1-0
PDS, placing the sutures at least 3 cm from the margin of the
incision. Oversew with a simple continuous suture of the same
- Close the subcutaneous layer with 0-0 or 2-0 Vicryl (depending
on the quality and thickness of the tissue, in a simple
interrupted or continuous pattern, taking care to close the dead space between the
subcutaneous tissue and the muscle.
- Prior to closing this layer, it may be flushed with dilute (5%)
- Use 2-0 Vicryl for the subcuticular suture.
Reversal of anaesthesia
- With the bear back in its cage, give atipamezole intravenously into
the jugular vein: 1 mL for each mL medetomidine
given within the last
hour, plus 0.5 mL for every 1 mL medetomidine given more than one hour
- For analgesia, carprofen, 1.8 mg/kg orally once daily for 3-4 days
(the dose may be increased to 1.8 mg/kg twice daily if the surgery has
been particularly traumatic).
- Antibiotics: enrofloxacin, 5.0 mg/kg orally
once daily for at least
10 days (tablets can be crushed and given to the bear in a fruit
- Note: bears from Chinese bile farms may have been given a
wide variety of antibiotics and infections may therefore be
resistant to many of the commonly-available antibiotics.
- Alternatively, amoxycillin/clavulanic acid may be given.
- Note: Culture and sensitivity assays are not generally
available for choosing antibiotics.