Case 1. Itchy Dogs.
Demodectic mange. In search of the anti-demodectic
Case 2. Itchy Dogs. Generalised ringworm
Dr Sing Kong Yuen, BVMS (Glasgow), MRCVS
First written: 01 February, 2013 Date:
06 February, 2013
Case 1. Itchy Dogs.
Demodectic mange. In search of the anti-demodectic
"I don't know
why your vet does not give the old dog an
anti-demodectic mite injection," I said to the
mother who "inherited" the 15-year-old Shih Tzu
from her daughter. The daughter, in her late
30s, had brought her to consult me for a second
opinion on January 30, 2013 was the owner of the
dog but had migrated to Australia.
The mother said: "My daughter in KL asked me to
consult you. My dog had skin diseases for so
many years except for one year 3 years ago. I
feed salmon and other good food. Every time, the
itchiness would recur after some time after my
vet had given a steroid injection. I hear
steroids are not good for my dog."
"I don't know why your vet has not or will not
give the anti-demodectic injection," I said.
"Did you ask him why? Did he do a blood test to
screen the health of this old dog, esp. the
liver and kidney functions? If these organs are
not normal, he might not want to risk giving the
injection. You can ask him to fax to me the
blood test results."
"Do you vets get along well with one another?"
the mother had not asked her regular vet why he
did not give the anti-demodectic injection. She
also did not want to upset her regular vet by
asking for clinical records for me to peruse and
get a bigger picture of the dog's health.
"All vets do fax or email copies of our client
reports to the 2nd-opinion vets when requested
by the owner to do so. There is no problem for
any vet in Singapore to do that as every vet
will have owners who want a 2nd or 3rd opinion
for his pet that does not respond to treatment
by the first vet." As the mother was not
comfortable to making the request, I did not
insist and took her history of what happened to
her dog from the beginning. She had brought some
medication given by her previous vet. These
included antibiotics, anti-mite cream and fatty
acid oil supplements.
"Some skin diseases are not easy to cure unless
the cause is known," I checked that this slim
Shih Tzu did not have hair loss, little scales,
four black paws with big skin warts, clean ears,
teeth with little tartar despite no dental check
up, a broken tail end with grey skin as if it
had partial gangrene and very swollen anal sacs.
"Now the paws are not so itchy," the mother
showed me a "poisonous" white cream that her
regular vet had given her maid who must wear
gloves to apply to the paws. "After applying the
cream, the mites die and so the dog does not
bite his paws so much. He also does not have
that red flush of the skin in the evening
causing him to cry and whine now."
The cream was formulated by her vet and so I
would not be able to tell whether it included a
steroid, hence accounting for the cessation of
"Listen carefully to the client," I said to my
intern from 4th year the Vet University in Kuala
Lumpur. "What she wanted was to get an
anti-demodectic injection." The mother had
said that her vet had done skin scrapings and
showed her "cigar-shaped" mites under the
microscope. "These are demodectic mites," I
referred to a chart drawing of demodex and her
daughter took an image with her hand phone.
The consultation was nearly one hour long as the
mother wavered on whether to get another blood
test done or get her vet to give me his results
and thereby offending this good vet. "I have a
bottle of 100 tablets of Eltroxin tablets," she
showed me and I have given half of the bottle.
My vet said my dog has low thyroid hormones."
She was reluctant to get a thyroxin blood level
"A thyroxin test will show whether the
medication is effective or not and on the status
of the low thyroxin level," I said. "In fact, a
repeat blood test is always advised to monitor
the disease some 4 weeks after the first and the
first blood test was 3 weeks ago." It was
hard knowing what was the situation since the
mother did not want to upset her regular vet.
So, this back and forth conversation took nearly
an hour. "How to cure the demodectic infection?"
the mum asked again and again.
"Demodectic mites are normally present in the
dog's skin," I said. "When its immune system is
below normal or low as in puppies and old dogs
like yours, the mites multiply and cause skin
itchiness and disease. So, increasing the immune
system would have helped considerably."
"How about giving my dog the anti-mite
injection?" she asked me. "A blood test is
necessary to screen the health of your dog
before I give the injection," I am not surprised
that Singapore dog owners nowadays are
sophisticated to know that some vets give
regular anti-mite injections to kill the
demodectic mites. However, this was a very old
dog and the injection might kill him.
"If the owner wants the injection, the vet ought
to give it," I said. "But educating the owner is
difficult. The best way is to boost the immune
system of your dog. Why does your dog lick all
four paws till they are black?" I had explained
that the large skin warts on and above the paws
irritate the dog as he tried to lick them off.
"Continuous licking to get rid of the paw warts,
cause the skin to break, become inflamed,
infected and ulcerated. After some weeks, the
melatonin skin pigments get inside the skin,
causing blackness of the skin of the paws.
Excising the warts would remove a stress for
this old dog and hopefully the demodectic mites
will not cause disease."
"But my dog is so old and will die under the
general anaesthesia," she replied.
"A blood test will show whether this dog is fit
for anaesthesia," I said. "The electro-surgery
the skin warts off the paws takes less than 5
minutes and I can say that the dog has a very
high rate of survival since anaesthesia is so
The daughter seemed to know what I was talking
about. The mother was pre-occupied with the
possibility of recurrence of the red skin flush
and loud whining in the evening, probably
stressing her so much. So we were at different
ends of the world. The dog was much better now
due to the variety of medications, the skin
cream and the fatty acid oil supplements but
this skin flush and whining might recur. Her
daughter would be going home to Australia in a
few days' time.
It needed a lot of patience. What the mother
wanted was a treatment to cure the disease once
and for all as she had spent a lot of money with
so many treatments by her regular vet.
What I proposed was to remove the stress factors
as treatment involved steroids and anti-mite
cream and/or injections which could harm this
"I will pay for the blood tests," the daughter
suddenly volunteered. Chronic skin diseases are
costly to treat and in this case, it was not
only the recurrence of itchiness and whining but
also money matters. Unless the cause can be
identified and can be easily treated, skin
diseases are hard to cure in some dogs. In this
dog, the ventral groin area is no long black,
due to previous steroid jabs. But the paws were
still black. On detailed examination, I would
say the big skin warts on the four paws would be
due to the spread of these viral warts by the
dog licking as the body seemed free of the warts
unlike other old dogs. The dog's anal sac was
voluminous with dark brown thick viscous oil. I
asked my intern to express the glands and she
managed to get 5% out. I showed her how to do it
and expressed over 3 ml of the oil while another
intern videoed the procedure. The broken tail
needed to be amputated. This was another advice
I gave and the mother said: "Earlier the tail
was black. I massaged it till the colour
returned." That meant the tail had become
gangrenous and is now half alive. The hairless
tip and broken angle of the tip would be an
irritant to this dog, decreasing the immune
system and encouraging the demodectic mites to
overwhelm his body causing red flush and pain of
whining. If only dogs can talk.
So, the first advice would be to remove the
warts and in most cases, the dog would become
much happier and no longer need to get rid of
these "dangling" tumours. Simple solution if the
dog was young and not an anaesthetic risk.
"Warts seldom appear in young dogs," I said to
the mother. "I had an old pug in which I removed
50 skin warts."
"Is the pug OK?" the mother asked.
"Yes," I said. Skin warts do irritate the older
dog but many owners are oblivious to this
discomfort of the old companion.
UPDATE ON FEB 6, 2013
A blood test to screen the dog's health and
thyroxin levels were permitted by the owner. The
test revealed a high level of liver enzymes. As
there is a high risk of death on the operating
table, the owner did not want any anaesthesia to
remove the paw
warts and the broken tail. The anal sacs were
expressed (videoed by an intern) and its
voluminous greyish oil disposed. As for the
anti-demodectic mite injection, this dog would
best not take this injection. What the
mother had sought in visiting me would best not
be given by the vet.
Case 2. Itchy Dogs.
A CASE OF GENERALISED
RINGWORM IN A SIBERIAN
HUSKY. The cure is permanent
if the dog is given the
correct medication for a
duration of time and unless
re-infected, it is usually a
very satisfactory clinical
outcome for the owner. No
need to see the vet many
In this case, the owner's
brother came to me seeking
some injections and
medication as the dog was
scratching and scratching
non-stop every day for the
I checked the hairs under
the microscope and showed
him the ringworm on the hair
strands. An intern from
Melbourne University is
tasked with making a video
on this microscopic
examination slides for the
benefit of pet owners and
- 5920. An injection & some tablets will not be
sufficient to cure generalised ringworm in a very itchy
Siberian Husky. Intern to produce video on microscopic
days after treatment - no
The dog stopped being itchy
7 days after treatment for
generalised ringworm and for
the next 30 days. However
the owner asked me why the
ringworm lesions become
black 30 days after
treatment. The hairs also
did not grow back. "The
pigmentation would be due to
the dog scratching and the
application of your
medication for some weeks
before consulting me," I
said. "The hairs should grow
back but it takes a long
time for some dogs."
Many small breeds grow their
full coat within 1-2 months. In his case, the
hairs seem not to grow at
all except for some fine
hairs near the upper neck!
ADVICES & TIPS
Seek veterinary advice
promptly if your dog or pet
keeps scratching for more
than 2 days. Ringworm can
infect people. Therefore,
early treatment is important
as it is a disease that can
- DERMAPHYTOSIS - PRODUCED
BY TOA PAYOH VETS INTERNS. A
very well researched piece
useful for vet students and
commissioned by me,
has been done by 4th year
Melbourne Univ veterinary
student, Vanessa Sim and
Raffles Institution JC
student Gina Ng. Many
of the fungal spore and
hyphae images are taken from
the Siberian Husky (above)
and photographed in my
microscope installed with
imaging software. It took a long
time to produce this video
but it is very well done.