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Date: Sunday, Jun 13,
2010
Case on a Sunday: Maltese X, Female, Not
Spayed, Weight 5.5 kg. 37.9 deg C. Active and eating.
Complaint: Pus below right eye. Rubs right side
of face onto bed sometimes.
3 Owners: 2 young men and a lady all around late 20s.
History: Had
consulted Vet 1 who prescribed oral Baytril 50 mg
antibiotics 1/2 tablet two times a day from May 16,
2010. But the owners gave the dog 1/2 tablet one time a
day as they deemed that the dog would be overdosed. The
pus in the facial wound disappeared after 2 days.
However the medication finished after 20 days and pus
re-appeared in the wound below right eye during last 2
days.
Diagnosis: Owners
knew the diagnosis of oro-nasal fistula as they had
researched the internet.
Prognosis: "It is
very high risk and the dog may die on the operating
table," I advised the owners to get a blood test done to
screen her health. The vet must inform the owner and the
owner is free to reject the advice. Since the owners did
not want a blood test, it was hard to estimate the
anaesthetic risk. In any case, such an old dog would be
very high risk.
I checked the dog's heart. It was OK. The dog was in
good bodily condition and had good body weight. So I
gave a 50:50 chance of success. Usually the chances are
less than 50%.
Pre-op:
1. Antibiotics IV with the drip or return after 5 days
of antibiotics for surgery.
The owners chose the IV drip.
Anaesthesia:
1. Isoflurane gas by mask. Intubate. This dog was not
able to sleep fully. When a loose tooth was extracted,
he would wake up partially and moved. So, I took out the
endotracheal tube, put on gas by mask and repeat the
intubation. After 3 episodes, I decided just to give
isoflurane by gas mask. 6 teeth extracted including the
right and left premolars. Dental scaling done. If the
dog had been sedated, he would have a smoother
anaesthesia. However, sedation may cause low blood
pressure or kill the dog and so in this case, I used
isoflurane gas only as it is much safer for an old dog.
This would also take a longer time to anaesthesize the
dog.
Surgery:
1. IV drip with antibiotics baytril was given before
surgery. The dog bit off the drip line before surgery.
2. Loose teeth were extracted. I was surprised to see
thick pus actually lodged in the roots of the right
upper pre-molar. Like a wallet full of cheese. I used
the forceps to scrape out the light yellowish pus.
Post-Surgery :
1. Two hours later, the owners came to bring her home.
2. No solid food for the next 3 days so that the big
holes from the extracted teeth would close . Just give
soup, milk or honey water for 3 days.
3. Antibiotics for 20 days.
This dog should live to a ripe old age of 20 years. "No
more white coat," the young man said. "As she grows
older, her coat colour became brown." I asked: "Did you
use yellowish shampoo?" "Yes," the owner said. "The
shampoo colours the coat over the years," I explained.
"If you use a "white-dog shampoo", the coat will not
become stained yellowish brown for a white coated dog."
All ended well for this well loved dog. I asked the
young man to sit on a chair and hold the dog and opened
her mouth. The dog kept moving her head. After 15
minutes, he could open the mouth and was surprised to
see a bleeding hole over 1 cm in size where the right
upper premolar was extracted. "I thought the pus come
from the front teeth or the fangs," the young man was
indeed surprised that the source was from the root of
the premolar 4. Fortunately, he could open the dog's
mouth so that he could see the hole and I could snap a
picture to educate readers.
This must be one of the oldest dogs in Singapore to have
an oro-nasal fistula. At this age, most teeth had
dropped off.
UPDATE ON JUNE 14, 2010
The owner phoned to say that the dog was coughing. "This
coughing was due to the irritation of the throat during
the many times of intubation, " I said. "It should clear
up within 2 days. Continue giving the antibiotics."
No further news from the owner after this.
VET PHARMACOLOGY
FOR VET STUDENTS
Baytril 50 mg (5mg enrofloxacin/kg bodyweight) is
advised by the manufacturer to be 1 tablet per 10
kg bodyweight once daily or as a divided dose
twice daily for 3 to
10 days with or without food.
For this dog weighing 5.5 kg, the dosage should be
1/2 tablet once daily or 1/4 tablet 2x/day. It
seems that Vet 1 advised double dosage at 1/2
tablet 2x/day.
In any case, the owners felt that the dog did not
need so much antibiotics. So they gave 1/2 tablet
1x/day (which is what the manufacturer
recommended) from May 16 for
20 days
till Jun 4, 2010.
Baytril was effective as the pus discharge
occurred only on Jun 11, 2010 (2 days ago). "What
did Vet 1 advised?" I asked the owner. "Vet 1 said
that the wound would not be going to heal and
would come back again. She advised dental work
after the antibiotics."
In this case, the owner was informed about the
need for "dental
work" and that the wound would return
again. They were also informed about the high risk
of anaesthetics and had cancelled a dental scaling
one year ago. However, in the case of oro-nasal
fistula, they had no choice. They were fortunate
that the old fawn coloured Maltese X survived. |
What is an oro-nasal
fistula?
It seems that the internet had much information for the
young owners, and so I did not need to elaborate.
Basically, it is a "canal" connecting the opening
(mucous membranes) in the sinus of the face to the roots
of the pre-molar 4 tooth. Bacterial infection in the
root of the pre-molar 4 form pus and destroys the sinus
creating a canal to below the eye. This pus leaks out
through the opening below the eye. It is also known as
carnaissal tooth abscess.
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