20 July, 2012
animals - dogs, cats, hamsters, guinea pig & rabbits.
Babesia canis in a Samoyed
Dr Sing Kong Yuen, BVMS
20 July, 2012
Be Kind To Pets
1062. Acute tick
fever in a big white dog in Singapore
July 4, 2012
Deaths of pets are part of my veterinary work since I
graduated in 1974. Yet, after almost 50 years in
practice, I feel much sadness in the death of this
beautiful snow-white big dog that died 4 hours after
arrival in my Surgery yesterday, despite treatment and
fluid therapy. She was middle-aged and quite plump, as
cuddly as a miniature polar bear. Not a brown stain on
her white coat. No skin disease unlike some others.
I had taken a blood sample and did the tick-fever test
for Babesia and Ehrlichia. The cause of death was
babesiosis (identified as Babesia canis by blood
smear), known as tick fever. The Ehrlichia test was
negative. I handed the print-out (left) to the owner.
"Would she have lived if Vet 1 had diagnosed
her with tick fever 8 days ago?" the lady in
her 40s had been referred by her brother to consult me
thinking that her dog had liver failure and no chance
I had told her that liver diseases are not a
death sentence but it may be cured if the liver is
infected, depending on the type of infections and
degree of liver damage. Vet 1 had given her many liver supplements
and doxycycline twice a day for 14 days. So she presumed her dog had liver disease
and had no hope since the dog became extremely
lethargic 8 days after consulting Vet 1.
"It is hard to say whether your dog would have lived
if she was diagnosed as having tick fever instead of
liver disease 8 days ago," I replied. Babesiosis is a
direct and an immune-mediated haemolytic anaemia. The
immune response is said to be more lethal than the
parasites (merozoites or piroplasm) inside the red
"Why didn't you consult Vet 1 if
your dog is not well after 2 days of medication?"
"Vet 1 did not tell me to do that," she replied. "He
gave me 14 days of the green tablets (doxycycline 100
mg/tablet), to give two tablets two times a day and
other medicine. But my dog stops eating and drinks
little yesterday. She was unable to stand up. She
vomited brown stuff and passed black stools and brown
urine. So, my brother asked me to consult you as he
had been to your surgery before."
"The antibiotic you gave is ineffective against
babesiosis," I said. "Your dog needed the anti-tick
fever injection and supportive treatments."
"Why didn't Vet 1 diagnose tick fever?" she asked.
"In his case sheet faxed to me, he did write 3
diseases. They are pyometra, tick fever and liver
"Why didn't he treat for tick fever?" she asked.
"He has written that you did not want the tick fever
test to be done. So, it is your decision."
"Why didn't he tell me that I should do the tick fever
test? Why did he ask me to take the antibiotics for 14
"He did advise you about the test and had written down
in his case sheet that you did not want the test
done," I said. "It is up to the owner to decide as the
owner pays for the test."
"Then why he did the blood test and the blood smear
for? The ultrasound too."
"He did the blood test to screen the health of your
dog esp. the liver and kidney functions. Your dog had
been sick for one week before you saw him. The total
white cell count was high. The platelets, red blood
cells and haemogloin were lower than normal.
"But the values were not excessively high," the
lady said to me. "So, there was not a big worry."
I noted that Vet 1 had written "refractile
inclusion bodies seen in the red blood cells."
This seemed to give a clue that it was possible that
the red blood cells had Babesia parasites. However, a
blood smear with the stains would reveal the
parasites. According to Dr Daniel, the blood smear
under Gram stain showed lots of red blood cells with
But the owner had not wanted the "tick-vector test"
and so the dog went home with liver medication,
anti-abdominal fluid swelling (ultrasound had detected
abundant fluid which was sucked out and examined by
Vet 1) and vitamins.
"My dog could hop into the car when I brought her to
see Vet 1," the lady said. "Now she just lay on her
chest and refused to stand up."
"What is her normal sleeping position?" I asked.
"Belly up, like people," she said. "She
would clean the Chow Chow's eye discharge every day
but now does not do it."
Eight days had passed. My blood test showed kidney
failure, elevated liver enzymes, a very high total
white cell count of 46 as compared to 20 when tested
by Vet 1. The normal range is 5-17. The platelets
were 26 as compared to 166 earlier (200 - 500). Red
blood cells were much lower.
"What are the purplish spots on her belly?" the owner
asked me when she came to see the dog at 9 pm
yesterday. The dog had passed away at around 7 pm.
"Those are areas of skin bleeding as the platelets
are very low," I said. "Your dog had difficulty
breathing and vomited blood before she passed away
The dog first showed lethargy 15 days ago. The
owner said that the dog had never gone downstairs and
had never got any ticks for the past 6 years. Since
this dog was so well groomed and never went
downstairs, I could believe her that the dog had no
exposure to ticks.
"Did the dog go to the groomer?" I asked.
"Yes, 2 months ago," she said. "I brought her to a new
groomer. But she had no ticks on her body when she
came back from the groomer."
"Why didn't you go to the old groomer?" I asked.
"He has stopped grooming since his groomer left."
"It is a strange case as a dog must be bitten by an
infected tick to get tick fever. Since you were so
sure that your dog never had ticks, Vet 1 might have
ruled out a high possibility of tick fever infection
and went for liver failure diagnosis."
In many cases, owners do not want laboratory tests.
However, the vet must be forceful in warning the owner
of the fatal consequences of tick fever if the dog is
not treated early. Refractile inclusion bodies in the
red blood cells were the clue as blood parasites like
Babesia can cause refractile inclusion bodies to be
It might be wise to treat as if the dog had tick fever
rather than following the protocol of confirming tick
fever, if economic reasons prevail. The interest of
the dog is paramount and if the owner cannot afford
the test, it may be advisable to strongly advise it
Did the vet phoned the owner 3 days after
consultation? I believe he had done so and he had
recorded in the case file. However, he wanted to speak
to the owner on the day he faxed the medical records
to me as the owner was with me. He told the owner that
he had tried to phone her 3 days after consultation,
but her phone was not responding.
"He could have added this
in after I asked for the medical report," the lady
owner had a very difficult time getting the report to
be released to me and therefore had her suspicions.
was the cause of death in this dog? Only an autopsy
would find the answer but the owner would not want
one. The dog was sent for cremation by her relative.
As to the possible cause of death, one experienced vet
said it was kidney failure rather than liver failure,
Dr Daniel told me. As for me, I would say that the
immune-mediated haemolytic anaemia reactions of
Babesia canis was the primary cause of the dog's quick
death rather than the destruction of the red blood
cells. Kidney and liver failures were the
My hypothesis is that the reaction caused platelets to
be extremely low and the dog would bleed internally to
death. In the evening when the owner came, she pointed
to several bruised like spots on the shaved abdomen
where the first vet had done his "abdominal tap" to
take out the peritoneal fluid. "These are bleeding
spots caused by the tick fever parasite reactions," I
said to the wife. The dog had coughed up some blood
It was one of those unusual cases as the dog was said
not to have been exposed to any ticks over the past
years as she lived in the apartment and never went
done for walks. If there was definitely no exposure to
ticks, the first vet was distracted and went for liver
failure diagnosis, disregarding the clue of the
presence of refractile inclusion bodies in the red
Singapore pet owners are getting more sophisticated
and demanding and therefore, evidence-based medicine
and defensive medicine must be practised nowadays. All
advices and client's objections to tests and advices
must be recorded properly in the case file as a good
habit. In this case, medical negligence would not
stand in court, I believe, as the vet did advise an
anti-tick vector test and the owner had been informed
and had objected to it. The burden of proof is on the
owner when negligence is alleged and the proof was not
there in this case.
All rights reserved. Revised: July 20, 2012
Toa Payoh Vets