Wednesday, 13 February 2013

11. Internship. An ossifying fibroma inside an old dog's mouth

tpvets_logo.jpg (2726 bytes)TOA PAYOH VETS

Date:   14 February, 2013  

Focus: Small animals - dogs, cats, hamsters, guinea pigs & rabbits
Trust & Audit: A rare case of a hamburger tumour inside the mouth of an old dog 
Dr Sing Kong Yuen, BVMS (Glasgow), MRCVS
Date:   14 February, 2013 
Be Kind To Pets
Veterinary Education
Project 2013-0131

Blog 1286.

Good dental hygiene is very important for people and dogs as some oral tumours form when the mouth is not clean. Yearly dental check ups will be ideal. In February 2013, I encountered a case of a dog with bleeding in the mouth and face. "Oro-nasal fistula also known as malar abscess or carnaissal abscess," I said to the two interns very confidently as this was a common problem in old dogs that seldom if ever was sent for dental check ups or scaling.

I was 50% correct. There was a large oral tumour shaped like an oval elongated tumour! Veterinary medicine throws surprising oral tumours to me even after 40 years of practice! The dog was eating food under this tumour which expanded to fit the length and width and height of the oral cavity. The length of this tumour was estimated to be 10.5 cm long. I doubt I will ever see another case similar to this.

Dr Daniel operated to remove this "hamburger" tumour using electro-surgery. I was present for a few seconds during surgery as this was his case and I had confidence he would be able to perform this surgery.

"There was a lot of bleeding," he told me when I audited this case on Feb 12, 2013 (yesterday) and phoned the owner as well. He packed the back of the mouth with gauze swabs to prevent inhalation of blood into the lungs. Around 90% of the length of the tumour was excised electrically and then the remnants.  He electro-coagulated the bleeders in the remnants so that there would be no more bleeding.  Electro-cautery was effective in preventing bleeding.

The 50% calculated dosage of domitor and ketamine IV anaesthesia was just sufficient for surgery, with top up of isoflurane gas via the mask. This formula is now used by the vets for IV anaesthesia. It took some time to convince vets that this is a safe and effective formula as all vets have their own judgments and preferences of using various anaesthetics. Stocking a variety of anaesthetics is very costly as they expire and so I don't permit associate vets to order their favourite or their vet professors' choice. A veterinary surgery must be able to sustain its profitability and most associate vets don't bother with this aspect as they are not accountable for the bottom line.    

Histology confirmed it is non-cancerous. It is known as a ossifying fibroma, originating from the soft palate according to the operating vet. There was also oro-nasal fistula which I diagnosed on first visual inspection and the rotten teeth black teeth as you can see from the image, were also extracted.  Blood test had not shown any abnormal findings and so this dog was fit for anaesthesia and survived without any problems.  In this case, the profuse bleeding from the excised tumour could be inhaled into the lungs and cause death by asphyxiation if electro-cautery had not been used to seal all bleeders successfully.

From my phone call, the gentleman owner of this dog is most happy. As far as the dog owner is concerned, his old Chihuahua is OK and eating and that surgical outcome is what matters in the final analysis. "How long has this tumour exist?" I asked him. "I don't know as I don't look inside the mouth," he said. This is a very rare case of a "hamburger" oral tumour.

Yearly dental check up of your dog over 3 years of age with your vet will prevent most oral tumours and rotten loose teeth.

1.  Electro-surgery was the correct choice.
2.  IV anaesthesia with top up IV would be the choice in this case as isoflurane gas use by mask was not practical. However, the IV anaesthesia at 50% had lasted a sufficient amount of time to complete 90% of the surgery and isoflurane gas top up was effective in this case.

IV anaesthesia top up, the drugs would be injected with the IV drip or the syringe with the drugs would be attached to the IV catheter.  

This webpage:
tpvets_logo.jpg (2726 bytes)Toa Payoh Vets
Clinical Research

Wednesday, 6 February 2013

9. Internship. A Terrapin with Swollen Eye Can Go Home

Swollen Eye Terrapin

Owner had bought 2 hatchling terrapins last September. They were fed with pellets, anchovies and shrimp. The water was changed daily however they were not put under the sun often. They had rocks in their tank for resting.

In December, owner started to notice that one of the terrapin wasn’t eating and it had both swollen eyes while the other one was thriving healthily. The sick terrapin was sent to Toa Payoh Vets on 22 January 2013 with the complaint of both swollen eyes.

 So it was treated with daily change of fresh water, sunbathing for 30 minutes, multivitamin supplement and daily antibiotic eye drops on each eye.

After 13 days of treatment, on 6th February the left eye was partially open however the third eyelid was slightly prolapsed. Though the improvement is very slight but persistency in treatment plan will eventually yield results. So it was sent home to continue with the treatment on 7th February.

In conclusion, the terrapin had conjunctivitis and usually for cases like this it takes a long time to heal. The other tank mate at home had grown big and healthy. 

8. Internship. Oro-nasal fistula in an Old Chihuahua

This text describes the processes of how a vet diagnoses & treats a case of oral tumours with tooth root abscess and oronasal fistula in an older Chihuahua. These processes form part of the Standard Operating Procedures at Toa Payoh Vets.

Owner noticed that the dog had swelling on the right side of the cheek for more than two weeks and later brought the dog to Toa Payoh Vets.

The patient: Chihuahua, Male, 10 years old, Singapore

There was swelling on the right side of the cheek however the appetite was still normal. The swelling had been there for more than two weeks. It seems like the old dog had oronasal fistula and tooth root abscess.

Life has not ended for this old dog as it was given a second chance by its owner. He had once been abandoned and later he found home with this kind hearted Singaporean who flew him all the way from Australia. He had journey far to reach his home sweet home.

The dog’s mouth is seldom examined by most dog owners and bad breath is usually tolerated by many Singaporean dog owners. They also seldom pay attention to the mouth part of their pet as long as the dog is eating without a problem.

Dental check up is not usually done and tartar will usually build up and rotten teeth fall off. Many owners are not bothered or are ignorant that dogs also need to have regular dental check up and dental care. However, the younger generation of Singaporeans are better educated and more concerned about the welfare of the old pets.

Back to my case.

One fine day on late January 2013, the owner of a male, 10-year-old Chihuahua noticed a swelling on the right cheek and brought it to Toa Payoh Vets.

At Toa Payoh Vets, Dr Daniel Sing was on duty. I was present.
“This looks like a case of tooth root abscess as you can see that the teeth are rotten and filled with tartar. There may also be oronal fistula. It is an abnormal communication between the oral and nasal cavities involving the soft palate, hard palate, premaxilla, or the lip” said Dr. Daniel.

Is it a case of tooth root abscess and oronasal fistula?
“So what are the treatment options available?” asked the owner.   
“For this case, we would recommend to go through surgery to remove all the affected teeth and clean the abscess” explained Dr. Daniel.
“But then how would my dog eat without teeth” the owner said.
“Don’t worry, the dog can eat soft canned food or even boiled chicken breast and porridge”
The financial costs and risk must be explained fully before any operation is done. But the owner must give his consent and that is where personality and financial conflicts come in. He must also be aware of the risk involve especially in older dogs. 

Blood test

Health screening is strongly advised before anaesthesia and surgery for all patients, esp. in the older dog.

Anaesthetic risks are much higher in old dogs. There is always the possibility that the older dog may die on the operating table. When the owner hears that the dog may die on the operating table, he may decide not to get the surgery done. Some deem the vet incompetent and consulted another vet. A health screening should be suggested by the vet to let the owner knows whether the risks are high or not.

"I advise a blood test to screen the health of the Chihuahua," Dr Daniel said.  The owners must consent to take the anaesthetic risk if they give permission for the surgery as in this case. No surgeon can guarantee zero risk in any anaesthesia, whether in people or animal.    

The total WBC 16.6 (normal 6.0-17.0)
Neutrophils 50.8%, Lymphocytes 19.2%, Monocytes 24.6%, Eosinophils 1.1%, Basophils 4.2%. The platelets count is 520 which is slightly above normal (normal 200-500)
This blood test indicates that the liver and kidneys were functioning normally.
"OK," the owner consented to the surgery.

Antibiotics were given to the dog.
IV anaesthesia without Intubation.   

Anaesthesia. What type? IV, gas or both? IV anaesthesia is shorter acting than gas anaesthesia. Intubation (a breathing tube connects anaesthetic gas and oxygen to the dog) is usually done in dental extraction.

After the dog had been anaesthetised, I discover that there was a big tumour about the size of palm size dough growing from the soft palate. This tumour occupied the whole oral cavity and the plan now had changed. We had to remove the tumour and the teeth as well. Therefore we can’t intubate the dog as the tumour is obstructing the endotracheal tube.

“Call the owner and inform him about the tumour and the plan to remove it and ask for his consent”
The owner gave his permission to proceed and the surgery continued.

Dormitor IV at 25% of calculated dosage for young healthy dog was sufficient for electro-sugical excision. Dental extraction was done after that.

The old dog survived the anaesthesia and that was what mattered most for the owner. It is not always possible for every old dog to survive anaesthesia during surgery. Therefore it is wiser to remove the tumour when it is smaller and when the dog is younger.


“Is the soft palate tumour cancerous or not?” the owner asked.
“Nobody can tell from the physical appearance,” I said. “The tumour needs to be analysed by the laboratory and the tumour cells can be seen under the microscope if there are any. This is the process of histology. Do you wish to get the tumour sent for histology?”
It is best to get the owner’s permission to send the tumour for histology to determine its state, as some owners may have budget constrain or do not wish to spend more money.


It is unprofessional to give medication to the owner to treat the oral tumour as some owners may insist on having them as an alternative to the high risk of anaesthesia during surgery as it will not disappear.
Electro-surgical excision of the soft palate tumour including extraction of molar teeth.
“The tumour can be removed from its stalk by using electro-cauterizer to avoid losing too much blood,” said Dr. Daniel. Then after removing the tumour, the dog started to wake up from anaesthesia, so it had to be gassed with Isoflurane. When it was down, Dr. Daniel proceeded with dental extraction of the molar and drainage of the pus.

Histology Lab Result

The result of the histology came out and the nodule is covered by squamous epithelium with overlying parakeratosis. At the centre, there were irregularly-shaped trabeculae of woven and lamellar bone. There is no evidence of malignancy. So this is good news for the owner is it was not cancerous.


The final diagnosis from the histology is ossifying fibroma mass, with tooth root abscess and oronasal fistula. The dog was put on antibiotic and two days after surgery it was allowed home.


Tips & Advices:

Post surgical management.

1.      Owner need to come back for review every 3 months for the next 12 months. Owner needs to be advised and reminded by the vet but this is seldom done by me.
2.      The mouth of older dogs must be checked by the owner daily and any mouth tumour can be removed when it is small. In this case, the whole oral cavity had been filled with the tumour. It could have existed for some months without the owner seeing it.
3.      TIPS: old and unhealthy dogs (>5 years) must be given 25-50% of the calculated dosage of IV anaesthesia for younger dogs to lessen risks of heart failure.

Prepared by,
 Erica Chai Hui Ling

Monday, 4 February 2013

7. Internship. Eye Infection in Red Ear Slider

video prepared by
Gina Ng and Erica Chai

6. Internship. Painful Squeak When passing motion in a guinea pig

video prepared by
Gina Ng and Erica Chai

5. Internship. “An Ounce of Prevention is Worth a Pound of Cure”

As the saying goes, this is applicable to all kinds of disease and especially to the ones that recur. Urolithisis or urinary calculi are the formation of mineral stones within the urinary tract especially the lower urinary tract such as the bladder and the urethra.

There are many factors that can cause urolithisis in dogs such as urinary tract infection such as cystitis or urethritis, breed disposition, diet, exercise, amount of water drank, age and sex. The formation of different types of stones depends on various factors such as pH of the urine, metabolic or anatomic abnormalities, and types of diet or genetic predisposition. Small breed dogs such as Miniature Schnauzer, Lhasa Apso, terrier, Shih Tzu and Miniature Poodle are predispose to stone formation as compare to large breed dog. Besides that, there is a high incidence of struvite uroliths in Miniature Schnauzer due to its genetic predisposition. Often diets high in certain nutrient such as calcium, protein, oxalates will also increase the risk of stones formation. Dogs fed solely on dry biscuits will make the urine concentrated which will cause the crystals to precipitate and favours the formation of stones.

There is no 100% cure to this disease as it had 30-40% chance of recurrence. This will not only pose problem on the animal but the owner as well. Animal that suffer from urolithiasis may have severe discomfort and pain and may even face death if the kidney is damage or if there is complete obstruction to the urinary tract. This will not only be inhumane but this also involves a large sum of money for the treatment as this may require emergency surgery. Surgery alone may range from $500-1500, and that will be followed by warding fees, medicine, pre-operation blood test, catheterisation, urinalysis, x-ray and many more. The total sum may reach a whooping of $1500-2000. Besides that, how many surgeries can the animal endure within few years of the episodes? Whereas prevention which consist of change of diet, exercise, monthly urinalysis which range from $30-50 and x-ray every 3 months which range from $50-70 will definitely be cheaper and more economically wise. This will not only put your pet out of misery but also save the life of your beloved ones.

Here’s a summary of treatment cost compare to its prevention:

Urine test
Prescription diet
Blood test

Urine test

Iv drip

Suture material

Stone analysis


Post-op nursing


In conclusion, many people may not want to follow and won’t bother to consider this regime. However from economic point of view this would be the best and not to forget other considerations like time, emotion, pain and life of your pet.

Prepared by 
Erica Chai Hui Ling

4. Internship. Enucleation of Winter White Dwarf Hamster

Surgical procedure:
1.       The hamster was gassed with Isoflurane in a small container for approximately 10 seconds until its body was limp.
2.       First we must incise 4mm of the lateral canthus so that we can have adequate exposure of the internal structure of the eye
3.       Then we can clamp the optic nerve stalk with the smallest forceps, however it is not possible to ligate the stalk because it is way too small.
4.       Next, is to incise the optic nerve stalk. Some bleeding may be expected after the incision however it will clot soon because the vessels are tiny.
5.       Then, we have to trim the upper and lower eyelids so that the skin will heal when opposed together. If these eyelids were not cut then the skin will not close even when stitched together.
6.       Lastly is to close up the wound using 6/0 absorbable suture.
7.       The whole eye enucleation procedure should take less than 1 minute because the anaesthetic effect wears off very fast in small animals especially when using gas anaesthesia.
8.       Clean the external of the wound and the surrounding fur that is stained.
9.       It is not possible to put E-collar on a hamster. So the best way to avoid self inflicted injury is to administer analgesic drug.
10.   This is because analgesic will provide comfort and the animal won’t feel irritated and pain. Thus, it will not scratch its eye.

NB: There is a simplified illustration of the procedure below.

1.       No 360˚ paralimbal incision to remove eyeball from its socket.
2.       There is no ligation of the optic stalk below the clamp.
3.       Lots of bleeding controlled by stitching of eyelid.
4.       Excision of upper and lower eyelid to create fresh wound.
5.       Excision of extraocular muscle attachment.
6.   Removal of the third eyelid or nictitans membrane

Prepared by
Erica chai Hui Ling

Sunday, 3 February 2013

3. Internship. A Golden Retriever With Two Big Lumps Below the Sternum


Ace is a 10 year old, male, Golden Retriever that came in with subcutaneous tumour and ruptured abcess (10”x5”x5”) below the sternum. He had been inappetance and had trouble walking for 10 days. During examination, he was down with slight pyrexia (T: 40.7˚C), deep ear infection, abscess, tumour and ulcerated foot pad of the right forelimb.

Possible treatment option:
1.       The dog required surgery to remove both the abscess and subcutaneous tumour.
2.       Excise about 1cm from the margin of the tumour to ensure complete removal.
3.       Then surgically debride the affected area and remove pus by flushing the abscess.
4.       Use hydrogen peroxide followed by chlorhexidine, diluted povidone iodine and then smear mixture of antibiotic cream and dermapred on the wound.
5.       Depending on the size, the gaping wound can be stitch up or left open for second intention healing and that would need daily wound cleaning.
6.       If the wound is big, we need to stitch up and reduce the dead space to avoid fluid accumulation. We also need to insert drainage such as Penrose drain to allow daily flushing of the wound.
7.       If the wound is small then second intention healing is intended. 
8.       The animal also needed systemic antibiotic, analgesic and anti-inflammatory medicine.
9.       If there is swelling, then apply warm compression twice daily.
10.   The dog had to wear a e-collar to avoid self trauma.
Prepared by
Intern: Erica Chai Hui Ling

Wednesday, 16 January 2013

2. Internship. Swollen right fore paw in a 12 year old shih tzu cross

Swollen right fore paw in a 12 year old shih tzu cross

Shih tzu cross, Male, 12 years old, not sterilised
Active: 5.8kg, in good condition
è Heart and lungs are okay
è No history of panting/ breathing difficulty
è No medical history
è Low risk
Problem: Foreign body under paw. Right front paw is swelling. Big scab/wound about 6mm in diameter. Might have stepped on something.

Treatment: Surgery to remove foreign body (found out to be a tumour)
History: Went for grooming about 2 weeks ago
Owner worried about effects of anaesthesia
Owner does not want dog to undergo histology (old age)

1. Internship. False pregnancy in a very old dog

False pregnancy in a very old dog 

Active, in good condition
è Food: Caesar can, Dog food (soaked in water) A & F dog food for old dogs, 1 egg everyday
è Drink: when asked to do so
è Pee: ??
è Poo: Once/ twice a day
Menses: Red, dark brown discharge, colour gets lighter towards the end,
Duration: 2 – 2.5 weeks (since young)
è Last menses: start of October
Has a breast tumour
Problem: False pregnancy
è Signs: Milk in breast
Problem: Itchy paw
è May be due to allergy to Dettol
Conclusion: Should have sterilised it 

- Toh Ming Hui