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INTRODUCTION
Certain breeds (e.g. Siberian Husky), old dogs
and intact (not neutered) males are more prone
to perianal (circum-anal) gland tumours. The
majority of tumours are benign and are called
perianal (circum-anal) adenomas. The malignant
ones are called adenocarcinomas. They can't be
differentiated by visual inspection. A
histopathology of the excised tumour is needed
to check whether it is cancerous.
TREATMENT - 3 OPTIONS
1. Surgical excision. Most perianal gland
tumours are benign but only histopathology can
determine whether they are benign adenomas or
malignant adenocarcinomas. Some vets don't
perform this surgery as there may be worries of
the wound not being able to heal and close. The
client may get very angry as the dog will keep
licking the open wound. Old dogs may die under
general anaesthesia on the operating table
leading to highly emotional scenes and potential
litigation.
These are two main reasons why some vets don't
want to operate. It may be kinder to pets for
such vets to ask the owner to seek a vet who
will operate as the dog licks the infected
tumours to relieve its pain. Blood dripping from
the backside can be quite inconvenient to the
owner. Owners may need to be proactive in
seeking early surgical removal.
2. Neutering. Perianal gland tumours are most
common in male dogs that are not neutered.
Seldom occur in female dogs. In this case, a
female spayed Siberian Husky had one such
tumour.
3. Hormone treatment.
Tardak is an anti-androgenic hormone. Injections
may be effective but need to be given regularly
when tumours occur.
Tardak is for use in male dogs and cats in the
following indications:
3.1 The treatment of hypersexuality (humping,
wanting to stray).
3.2 The relief of prostatic hypertrophy whether
benign, carcinomatous or when due to chronic
inflammatory processes. In inflammation,
antibiotics and anti-inflammatory drugs are used
too.
3.3 For the treatment of circum-anal (perianal)
gland tumours.
3.4 For the treatment of certain forms of
aggressiveness, nervousness, epileptiform
seizures and corticoid-resistant pruritus
(developing into dermatoses and accompanied by
alopecia).
4. Chemotherapy and radiation for cancerous
types. This is not normally available for
Singapore dogs.
INTERESTING CASE STUDY
Female spayed Siberian Husky, 11 years old
suffered from blood dripping from her perianal
tumour for over 4 months. Tumour ulcerates and
become infected. If you see the black spot below
and to the right of the anus, there were early
signs of perianal gland irritation, as the black
spot is due to continual licking over several
weeks.
CHALLENGES
1. High anaesthetic risk as in all old dogs. The
owner did not wish to have a blood test. The vet
must inform the owner of the need for such a
test to screen the health of the dog before
anaesthesia and surgery.
2. Large tumour over 3 cm x 3 cm very close to
the anus. That meant a large wound after removal
of the tumour and difficulty in achieving normal
closure.
3. The dog passes soft stools during surgery,
resulting in possible contamination during
surgery and after.
4. If the dog rubs her backside on the floor
after surgery, the stitches may break down. A
large e-collar prevents licking of the wound.
PLAN AHEAD
I advised the owner to get her vet who did not
want to operate, to do full grooming esp. of the
tail area, ensure no maggot wounds and prescribe
oral Baytril antibiotics for 6 days.
PRE-ANAESTHESIA
On the 6th day, the wound was not infected. The
dog's rectal temperature could not be taken as
the dog struggled and leaked out urine whenever
her tail was to be held up for the insertion of
the thermometer into the rectum. She was in
great pain in the anal area and tried to bite to
defend herself. More urine leaked out as she
struggled. I got her muzzled for the IV drip and
the injection via the IV catheter of Domitor
0.15 ml.
ANAESTHESIA
Dog got shaved. Isoflurane gas was given by
mask. I intubated the dog and isoflurane at 1-2%
ensured surgical anaesthesia. I got a towel to
cover the metallic operating table to prevent
electrical shock when I used electro-surgery to
excise the perianal tumour. A swab with saline
was placed on the indifferent plate and the
dog's belly for the conduct of electricity
during electro-incision and cautery.
ACTUAL SURGERY, JUNE 9, 2010 FROM 2.17 PM -
3.15PM
1. I used electro-incision to cut off the
tumour. The dorsal part has a dark red mass of
0.5 cm x 0.5 cm. The main mass was hard, nodular
and ulcerated. It was 2.5 cm x 2.5 cm. The
shorter the surgery, the better the chances of
survival.
2. A small artery at the ventro-lateral area
nearer and below the anus spurted out red blood.
I ligated 3 times. Coagulated the bleeding
point. Finally, there was not much bleeding.
3. As the elliptical gap was large and under
high tension, I had to reduce the tension in
order to enable good wound healing. I extended
the skin incision to the left at the dorsal and
ventral edges above and below the anus
respectively (see illustration). The wound was
stitched with 3/0 sutures.
4. During closing, this dog kept passing out the
loose stools despite her rectum being plugged by
a 3-ml syringe. I replaced this syringe with a
5-ml syringe but the stools kept pouring out.
This was be possibly due to the minimal
isoflurane gas being used and therefore the
dog's defaecation reflex was present. The dog's
tongue was not a healthy pink and sometimes it
turned cyanotic. Since the owner did not want a
health screening blood test, it would be
difficult to know if this dog had anaemia,
hypercalcaemia, kidney or liver disorders.
POST SURGERY
The dog woke up within 10 minutes as if she had
a good nap of over 30 minutes.
I gave 2.5 ml of anti-spasmogesic IV to prevent
more loose stools coming out to contaminate the
wound. She wore an e-collar. I phoned the owner
to take the dog home. They came to visit her in
the evening.
HISTOPATHOLOGY
The vet must inform the owner that there is
histopathology to verify whether the tumour is
cancerous or benign. In this case, the owner did
not want it.
CONCLUSION
Neutering and surgical excision are recommended.
Tumours are best removed when they are very
small. I advise two anti-androgenic injections
post surgery at 2-weekly intervals. Neutering
your male dogs when they are young and/or weekly
examination of the anal area will ensure that
your dog live longer. This case has a happy
ending. However, vets are not Gods and there
will be deaths of old dogs on the operating
table. It is best that the owner gets the
tumours excised when they are very small in
size.
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TOA
PAYOH VETS
