Wednesday, January 23, 2019

3405. Debarking of dogs - case studies - Pt 1



Ventriculocordectomy (debarking surgery) and alternatives in the dog
 
Dr Sing Kong Yuen, BVMS (Glasgow)
First written:  1 May 2010
Update:  23 January, 2019
Non-stop barking affects the neighbour's sanity and peace. In Singapore, over 80% of the residents live in HDB (Housing and Development Board) apartments.  Residents who work shifts can't sleep, pregnant mothers and babies don't have peace of mind due to the anti-social noise nuisance of non-stop barking dogs.

After complaints are lodged, the dog owner living in the HDB apartments gets a warning from the HDB to control the barking. If complaints continue, the AVA (Agri-Food Veterinary Authority) may tell the owner that the annual dog licence will not be renewed. Statutory fines of up to $5,000 will be imposed if the dog owner keeps the dog without a licence. The owner has to resolve the problem or euthanase the dog.

This report discusses the debarking surgery and the alternatives to surgery.


PART 1. VENTRICULOCORDECTOMY USING THE VENTRAL APPROACH

In the interest of dogs who will need debarking as an alternative to death by lethal injection, I share knowledge of the devocalisation surgery with new veterinarians who may need to de-bark the dog using the ventral approach.

It is not a common surgery in my practice or in Singapore. Debarking is strongly discouraged as it is deemed cruel. In my over 40 years of practice, I had performed 5 surgeries using the ventral approach. The main problem is the bleeding control. Bleeding obstructs the view of the vocal folds especially in using the less expensive oral approach.

I use the ventral (laryngotomy) approach only. It is more effective but costs more as it takes more time.

Anaesthesia
The surgical area where the vocal folds are located is not accessible if I use isoflurane gas anaesthesia as the endotracheal tube obstructs the view. Tracheostomy with the endotracheal tube has been mentioned in one veterinary book (Small Animal Surgery - T W Fossum). I have never used it.

Nearly 100% of my surgeries is done with isoflurane gas anaesthesia and it is very safe. But in this surgery, injectable anaesthesia is preferred. I am recording one case of debarking using electro-surgery and injectable anaesthesia as some vets may need such information and may be researching the internet for such information.

Case study using injectable anaesthesia
PatientBichon Frise, Male, 6 yearsWeight: 6.5kg
Barking non-stop since he was a puppy. Living in Canada was not a problem, but now, he lives in an apartment in Singapore and there were many complaints about his dog.

Two main challenges in debarking
1. Surgical anaesthesia using isoflurane gas is difficult to attain due to the need to pull out the endotracheal tube to expose the vocal folds in order to perform he surgery. The dog wakes up from the anaesthesia in the midst of surgery and moves. The tube needs to be re-inserted to get the gas back to anaesthesize the dog. Therefore, injectable anaesthesia is preferred but the risk is higher if the doses are not given just sufficient to maintain surgical anaesthesia.

2. Bleeding from surrounding muscles is a main worry as the surgical view will be bloodied. Electro-cautery seals the blood vessels well in this case. Without electro-cautery, there will always be continuous bleeding, obstructing the views and increasing operation time.

The following procedure (ventral approach also known as the laryngotomy approach) has been done successfully for this dog.

I/V drip Hartman.
Xylazine 20 @ 0.2ml + Ketamine 100 @ 0.1 ml in one syringe via the IV catheter

Maintenance of anaesthesia
When there is movement during electro-surgery, Pentobarbital (Nembutal) 6g/100 ml is used to maintain the anaesthesia. I gave 1.0 ml via the IV catheter. A total of 2.0 ml Pentobarbital was given in this dog. There were no adverse effects.

Electro-cautery provided excellent bleeding control. I did not suture the mucosa after excision of the vocal fold as advised in one veterinary book (Small Animal Surgery - T W Fossum). It seems to be an impractical advice as there is not much area to suture. I don't do subcutaneous suture as advised in this book as more sutures mean more irritation. I used absorbable sutures and so I don't get to see the busy owner post-surgery for stitch removal.

Advantages of electro-surgery
Bleeding blood vessels in the neck muscles are cauterised.
A blood-less field.
Vocal folds pulled with forceps - around 5 mm in length is electro-incised. Clear of blood in this case.

Day 1. Tolfedine 4% at 0.5 ml SC and Ciprobay 0.5 ml given via the IV drip post-operation.
Day 2. Reviewed 24 hours after surgery. Dog had eaten and had no fever. When I cleaned the surgical site, the dog did not object as the pain-killer Tolfedine was effective. The dog went home on Day 4.
 

Ventriculocordectomy or euthanasia for nuisance barking in apartment dogs.Toa Payoh Vets
"The Bichon had been barking as a pup," the young man said. "He barks the whole day and the HDB neighbours are not happy." 

"I seldom do this laryngotomy surgery," I informed this owner. "How many surgeries have you done?" he asked. "Around 5 cases done in my 40 years of practice. "I don't do it unless it is in the interest of the dog." In this case, the dog will be evicted or euthanased as an anti-social nuisance if no debarking surgery is done. 
Notes:

Small Animal Surgery - Theresa Welch Fossum advises to be careful to avoid disrupting the blood supply to the larynx and trachea during surgery or necrosis may result during the ventral approach.

Dog World Nov 2008: Page 31. Training Topics. The Bichon Frise has a high-pitched bark that test the owner's nerves and the neighbour's patience. He barks at every new happening in the neighbourhood. Training a Bichon to stop barking on command is advised. The Bichon is not the easiest to housetrain and difficulty in housetraining is the biggest reason it is turned over to the rescue group.

P.S. I strongly discourage devocalisation (debarking) and advise training. I reject debarking using the oral approach as it is not very effective. However, it is a cheaper alternative and some owners opt for this approach.

In this case, using the ventral approach, I have no complaints from the dog owner as regards the recurrence of barking, annoying neighbours and leading to complaints to the veterinary authorities. It is 6 months after the surgery.  

Case study of ventral approach using isoflurane gas anaesthesia
A Beagle barks every few minutes

PART 2. VENTRICULOCORDECTOMY USING THE ORAL APPROACH
For the benefit of the younger vets, I record the following oral approach that has been done.

The oral approach is much less invasive. It is cheaper and faster. However, it is not very effective in many cases and most vets prefer not to use this approach since the dog's barking volume has not been reduced considerably. This leads to complaints about ineffectiveness.  However, this approach is costs less and many dog owners prefer this. Owners must be told that this approach may not be effective and an informed consent and recorded advice must be obtained.  

Jack Russell, Male, Neutered 10 years old.  As last resort, the young girl had to de-bark her dog due to complaints.
I noted a plastic spiked collar (with spikes facing the neck).

1. Blood test done first on Jun 11, 2010.
Normal except that kidney shows in umol/L that urea is 3.9 (4.2 -6.3), creatinine is 61 (89 - 177). Dog was OK for surgery

Jun 17, 2010, 6.5 kg, 39.2C
2 pm Surgery
IV drip
Domitor 0.2 ml IV, Zoeletil 100@ 0.1 ml IV
Atropine 0.5 ml IVAnaesthesia insufficient. Needed to top up Zoletil 100 0.1 ml IV


General Anaesthesia
General anaesthesia using injectable anaesthetic like domitor and ketamine IV at the correct dosage may be used. An i/v catheter may be inserted for topping up of IV anaesthetic when the dog reacts. Or use isoflurane gas to top up.

Surgery
The dog's head is held by an assistant who should not place his hands under the throat. The vet pulls out the tongue to view the vocal cords. There is a sideways movement of the vocal folds. An long curved artery forceps clamp the vocal fold. A curved scissors with sharp tip then snips off the upper and lower edges of the end of the artery forceps as shown in the image below. In the image, the artery forceps had clamped the vocal fold a bit too high up and would be re-clamped again. Alternatively, a biopsy punch can also be used instead of the artery forceps and scissors combination.   


ventriculocordectomy-devocalisation_dog_toapayohvets ventriculocordectomy-devocalisation_dog_toapayohvets
tpvets_logo.jpg (2726 bytes)5390 - 5391. The oral approach
There will be some bleeding depending on the extent and accuracy of the excision of the vocal fold. A forceps with sterile cotton wool is pressed against the cut area to stop the bleeding. Results vary depending on how accurately the amount of vocal fold that can be cut off. 

PART 3.  ALTERNATIVES TO DEBARKING SURGERY
It is easy to advise training when you don't have to face angry neighbours or are told to evict your dog or get slapped with a $5,000 fine for keeping a dog that will not be licensed or that its licence will not be renewed.
"Debarking is a rare operation," I said to the lady on the phone. "We don't encourage it." She had moved to a quiet neighbourhood and her 8-year-old neutered Schnauzer barked shrilly and frequently. "I want to debark my dog to prevent the AVA from coming to see me after neighbours complaint. The alternative is to give up this dog but I do not want to give him away."

Barking seemed to be her only solution and she googled for a vet that will do debarking. "Do you need me to consult you first and be counselled for debarking? My vet is at .... Do you mind that?". She was advised to try training and other alternatives.

"Will scars form after debarking, affecting the dog?" the lady had read somewhere in the internet

"Scars are referred to operations after debarking. As the vocal cords may not be excised by the long forceps 100% unless done by the vet with lots of experience using this approach, the scars will form. Barking sounds will return."


SUMMARY OF THE ALTERNATIVES
1. Get a dog trainer to train the dog not to bark will need some time and patience. It may or may not work. It is expensive. 

2. Electric collars. It works according to feedback from one owner. The use of electric collars may be successful for some owners who have time or inclination to do the training.

3. Citronella spray collars. Bark collars emitting an unpleasant scent when the dog barks are said to be ineffective and expensive. Some dogs get rid of the collars and resume barking. Feedback from some owners are not so positive.

4. Other methods like "Throw cans with coins or pebbles when the dog barks, without him seeing you do it," I advise puppy owners. "Squirt water from a water pistol when he barks."  One successful owner told me, "Grip the dog's muzzle and say 'no barking'". This advice is mentioned in some doggy magazines.

5.  For all puppy owners, spend time during the first 2-4 weeks to train the puppy not to bark at all times. Otherwise, they grow up barking for long periods of time.
Success depends on the age of dog, the personality of the dog, the training and the owner. It is hard to be specific.

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