0122Singapore pet health and welfare educational for animal lovers, excerpts from The Glamorous Vets, Singapore, sponsored by  AsiaHomes Internet.

"Vomiting during anaesthesia"

It was past eleven o'clock on a fine Sunday morning. A male eleven-year old, trim and in excellent bodily condition crossbred brown dog with the  and snow white teeth of a two-year old was brought in for consultation.

"Doc, is there any injection to remove his nose lump?" asked Mr Kurth.   "I would be travelling for the next 3 weeks and my dog is irritated at some growth on his nose."

"No injection would remove this tumour," I replied.  An ulcerated strawberry-like tumour (see excised tumour on triangular piece of paper) on the right bridge of the nose, around 2.5 cm diameter has grown over past few months and the owner thought some injections might vanquish the growth. 

"Your dog will need to be anaesthetized so that the lump can be surgically cut out.   Has your dog been eating or drinking during the past twelve hours?"

The dog had dinner at 7 p.m yesterday and it was already sixteen hours ago.  The food in the stomach should have been digested.  At least, the food should have left the stomach.  

Sunday was a busy day.  It was a minor operation and not an emergency. However, the dog had been rubbing his right eye and I could see tearing stains where the upper and lower eyelids meet near the nose.  The similar area was clear of stains in the left eye. 

If he was not operated, he could scratch his eyeball and become blind.  That would be worse.  In any case, his owner had no time for another day as he was a regional expatriate manager travelling 3 weeks out of four in a month. 

I tranquilized him with the xylazine drug injecting into his back muscles.  The maximal effect would be fifteen minutes.  Then, he would be put on the operating table and given the general anaesthetic.  The growth would be cut out and three nylon stitches would close the surgical wound.

There was a loud sound from the doped dog ten minutes after tranquilisation.  He had vomited the chicken meat and gizzard. According to the text books, his stomach should be empty.

Nurse Ann cleaned up the mouth.  We put him on the operating table.  The endotracheal tube was put into his throat and into his windpipe. It was then connected to the anaesthetic machine and halothane gas was given to make him fully unaware of the pain of surgery.

"Stage four reached," said Nurse Ann.  Stage four meant that the dog was in deep surgical anaesthesia and I could commence surgery.  Nurse Ann reduced the halothane gas from 5% to 1.5%.  At seventy-seven human equivalent years, this dog was an anaesthetic risk.  He had heart murmurs and we minimized risk by giving as low a maintenance dose of gas as possible.  

Just as the scalpel blade incised the base of the tumour, a copious amount of yellow watery fluid gushed out from the dog's mouth and into the drainage channel of the operating table.  The owner had said that he had not drunk water since last evening.  

The operating area was now contaminated with gastric juices and water from the vomitus.  

"The dog is waking up," shouted Nurse Ann.  The 1.5% halothane was just low but would have been all right if the surgery had proceeded. The surgery would take only five minutes, but now twenty minutes had lapsed in cleaning up. The dog's eye lids were blinking.  His legs were paddling. He was out of the deep stage and was not happy with the endotracheal tube which had prevented the vomitus from entering his lungs.   If there was no entrotracheal tube, he might catch a fatal inhalation pneumonia if he had inhaled the vomitus.

The reason for fasting the dog for twelve hours was to ensure that there would be no vomiting.

For an old dog, the shorter the anaesthetic time, the less likely he would die from heart failure and other complications.  Now, the time had been prolonged.

The endotracheal tube was removed and a pentobarbiturate injection was injected into his leg vein to knock him out for the next five minutes.

I cut off his tumour and stitched up the wound quickly with two nylon stitches. Was the dog starved for over twelve hours?  In very rare cases, it was possible that the food could remain in the stomach for more than twelve hours, although the text book on digestion mentions four hours. There are always exceptions to the rule.

This case emphasizes the importance of the early removal of small skin tumours and a yearly veterinary examination if you want your dog to live longer.  The skin tumour on the nose could have been quickly and easily removed in less than 5 minutes of general anaesthesia when it was just a small nodule of less than 2 mm.