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Focus:
 Small animals - dogs, cats, hamsters, guinea pig & rabbits
Date:   29 December, 2014  

Corneal Dermoid cases in the Shih Tzu in
2003, 2009 and 2014

2003 Case: A Case Of A Mis-diagnosis. The Shih Tzu had a Dermoid, Not a Pterygium
Dr Sing Kong Yuen, BVMS (Glasgow), MRCVS
Case first written in 2003. Case updated:
29 December, 2014


"Have you snipped off the Shih Tzu's hairs growing from the white tissue covering the left side of its cornea at 9 o'clock?" I asked the pet shop girl for the fifth time over several days. 

The thick white tissue was snow white and looked like a wing. Hence its medical term is  dermoid.  People like sun lovers do suffer from dermoid which is said to be caused by excessive exposure to ultraviolet light but this puppy was born with a dermoid.
Singapore 2-month-old Shih Tzu puppy with pterygium in the right eye
The dermoid had grown from the conjunctiva which is the tissue covering the sclera (eye white) and advanced to cover the left side of the cornea of the right eye.

When the pet shop girl wiped the eye discharge during one of my visits, I saw hairs growing from the dermoid which is unusual as a pterygium should not have hairs. (THE EYE CONDITION IS A DERMOID, NOT A PTERYGIUM - see e-mails below).

These hairs irritated the eye and cause inflammation and eye discharge overnight.

It was uncomfortable for this puppy and I could only pester the pet shop girl to snip off the hairs as veterinary surgery was not advised in such a young age.

"No," the pet shop girl apologised. "I have been busy with my work." She needed to be careful not to puncture the cornea and that might be the reason she had procrastinated. 

The pet shop girl loved animals and usually swiped off the sticky yellow eye discharge with a piece of tissue paper before showing me the puppy. I saw the hairs clump together and stand out vertically during one such visit.

The discharge was seen the next day when I visited the pet shop to vaccinate the other puppies. The puppy would feel uncomfortable and rub the eye. Soon, it would get infected sore eyes. 

This three-month-old Shih Tzu pup was amongst ten imported from Australia.

"Can the dermoid be removed by surgery?" the pet shop proprietor asked as I vaccinated the puppies.

He would not be able to sell it as fast as the other puppies. Who would want to buy a defective puppy for nine hundred and fifty dollars?

"It happens to other pet importers too," I said. "Some Australian pet exporters will throw in a healthy puppy with a defect occasionally and this means extra veterinary costs for treatment or a loss for you as nobody wants to buy the puppy." 

I examined this very cuddly  Shih Tzu. "The surgery will not remove this dermoid completely as there are chances of recurrence. There will be a scarred tissue over the cornea where the dermoid had been removed."

I elaborated: "A very young puppy is a high anaesthestic risk and it may die on the operation table."  This means a total loss to the pet shop proprietor.

"Furthermore, there will be a scarred cornea after removal of the dermoid and therefore the defect would still be obvious."

What the pet shop proprietor wanted was a clear cornea and if I could not give him what he wanted, I should not advise surgery as this would cost him money.  The anaesthesia and surgery would cost him at least two hundred dollars.

Singapore shop rentals are very high as demand is greater than supply and it is best to save him money if the cosmetic surgery would not guarantee a perfect clear cornea.

"It will be better to inform the prospective buyer of the eye defect, sell it much cheaper and let the new owner seek veterinary treatment." 

The pet shop proprietor decided to sell the puppy at a lower price but there were no buyers for the next two weeks. The older the puppy grows, the harder it will be to sell to most Singaporeans as they buy the youngest puppies available.

I remember this Shih Tzu very well as dermoids are rarely encountered by veterinarians.

Snipping off the hairs would help and it was best done by the pet shop girl.
I guessed there was too much harassment from me.  On the sixth phone call, the pet shop girl who was also a very experienced and fast dog groomer finally took up her scissors to trim the hairs. 

Singapore 2-month-old Shih Tzu puppy with pterygium in the right eye "Are there any more eye discharge the next day?" I asked her.

"Much less," she said and continued with her work.

"Was there anybody interested in buying this puppy?" I asked as three weeks had passed.

"No," she replied. "The right owner had not presented himself yet." She believed in fate. Fate brings people and circumstances together. 

I doubt anybody will buy this Shih Tzu. What will happen to this Shih Tzu if there are no buyers? I don't really know.

When it grows older, surgical removal of the dermoid will be needed as it affects the vision. My concern was the inflammation of the eye as the dog may feel that it has a foreign body and keeps rubbing its eye, leading to blindness later in life.  

Many Singaporean pet owners tend to get advice from the pet shop girls who will usually suggest eye drops for eye problems in their pets to save on veterinary consultation costs.

Many will use the potent eye drops prescribed for members of their family. No amount of eye drops will dissolve a dermoid.  This Shih Tzu would need surgery when it is older to get the dermoid removed by the vet.

2003 Case: A Case Of A Mis-diagnosis. The Shih Tzu had a Dermoid, Not a Pterygium. Amendments made.

Correction: Puppy has a dermoid, not a pterygium in the eye. Toa Payoh Vets
 
E-mail on April 11, 2008

Dear Judy
I am an eye surgeon in UK and by chance came across an article (see
link: 031803Shih_Tzu_pterygium_Singapore.htm
(above report), which I believed originated from your practice. I know it has been a while since it was written but I just wanted to inform the vet that treated the dog's eye that it is a dermoid and not a pterygium. It has hair as the lesion is a teratoma. It can be removed by superficial keratectomy but it is much more difficult than removal of a pterygium and may be a patch graft (not sure if this is available for dogs?). Hope this helps
b/w
Say Aun Quah

 

E-mail reply on April 20, 2008

Hi

I am Dr Sing from Toa Payoh Vets. I am very grateful to you for taking the time to write to us. We could not find the article to correct the mistake earlier. 5 years have passed quickly as the pictures were taken in 2003 . It is good that you have found the article in the internet and informed us. The puppy's eye condition is a dermoid, not a pterygium.  Thank you for writing to us. Amended pictures are presented as follows:

 

Dermoid in a Shih Tzu's eye seen by Dr Sing in 2003. Toa Payoh Vets Dermoid in a Shih Tzu's eye seen by Dr Sing in 2003. Toa Payoh Vets
Dermoid in a Shih Tzu's eye seen by Dr Sing in 2003. Toa Payoh Vets Amendments in the above pictures. The Shih Tzu puppy's right eye condition is a dermoid, not a pterygium as labelled in 2003 pictures in the report above
   
2014: A Case Of A Dermoid in a Shih Tzu videoed at Toa Payoh Vets
   
Video: Dermoid in a Shih Tzu's eye  
   

CORNEAL DERMOID SURGERY IN DOGS


It seems that corneal dermoids are rare in young dogs in Singapore. These few cases I am aware of, occur in Shih Tzu puppies. Shih Tzu breeders may see more cases than vets. A quick internet check - one case in a Shih Tzu in another country. See the internet posting reproduced below:

2005 website posting from the internet of a dermoid in a Shih Tzu

Hello, I just purchased a shih tzu from a breeder. Two days before I picked him up, I was told that during the vet visit, it was found that the puppy has a lateral corneal dermoid cyst on its left eye and must be removed. I was a bit hesitant but the opthalmologist assured me that this has no long term effect on the shih tzu and that it will live a normal life with no visual impairments. I took the precious puppy home after the surgery and he seems to be doing fine. I have been applying antibiotic drops three times a day to the affected eye. However, there is a white film that is visible on the operated eye. Has anyone had this experience before? Is that normal? I am just worried.

   
   
2009 Case: Corneal Dermoid Surgery in a Shih Tzu at Toa Payoh Vets
Dr Sing Kong Yuen, BVMS (Glasgow), MRCVS
Case written:
29 December, 2014

The owner requested surgery to remove the corneal dermoid as it was impairing the dog's vision. In 2009, I had not started using videos. The surgery was recorded using images.
Dermoid cyst, eye, Shih Tzu, 8 months. Toa Payoh Vets, Singapore Dermoid cyst, eye, Shih Tzu, 8 months. Superificial keratectomy. Toa Payoh Vets, Singapore
Dermoid cyst, eye, Shih Tzu, 8 months. Superificial keratectomy. Toa Payoh Vets, Singapore Dermoid cyst, eye, Shih Tzu, 8 months. Superificial keratectomy. Toa Payoh Vets, Singapore
Dermoid cyst, eye, Shih Tzu, 8 months. Superificial keratectomy. Toa Payoh Vets, Singapore Dermoid cyst, eye, Shih Tzu, 8 months. Superificial keratectomy. Toa Payoh Vets, Singapore
Dermoid Cornea Shih Tzu 8 months keratectomy Toa Payoh VetsMore information about the anaesthesia in the 2009 case is at:
Dermoid Excision Using Electro-surgery

 

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