The young couple consulted me as to why the 13-year-old Shih Tzu had a "white" spot in the right eye. The spot had appeared recently.   

Just give some eye-drops and send the old Shih Tzu home with antibiotics? This would probably be the path taken by some vets. This case needed more detailed examination of the eye under general anaesthesia.

"Will the old dog die under general anaesthesia?" the couple was worried as they must have heard stories of dogs dying on the operating table. The risks are higher in old dogs. Old dogs in poor health as in this case.

So, just give some eye-drops and send the oldie home with antibiotics? This will not result in a satisfactory outcome.

Surprisingly, this old dog does not have heart disease. I gave isoflurane general anaesthesia by mask and intubate.  It was not possible to have a short anaesthesia to minimise the risk of death as the dog had bad teeth. My hypothesis is that the bacterial from the upper premolar teeth had broken through the sinus to the right eye ball causing a bacterial infection of the eyeball. The dog rubs its eye and a white patch appeared in the centre of the eye. As it rubs frequently, the white patch which used to be a pigmented black area gets injured. A hole of 2 mm in diameter due to corneal rupture appeared. From this hole, the pus leaks out from inside the eyeball. So, the young couple sees a "white" spot appearing every day. A leaking tap of pus which is yellowish white.

In theory, the eyeball should be enucleated or removed. But this is a drastic surgery and terribly emotional for the couple. So, I removed pus from the upper eyelid by excision and draining the pus. Antibiotic eye ointment and oral antibiotics were given in addition to 3rd eyelid surgery. I had the poor dog's coat clipped short so that it would feel comfortable. Will this work?

3 days later, the couple came to say that the dog was shivering. "Is it eating and drinking normally?" I asked. "No problem."  I palpated the right eyeball.  No pain. "Clipped dogs may shiver," I said. "Most likely, it is the pain inside the eye." Hard to tell what causes this shivering. Could it be the effects of the antibiotics?

I checked the mouth. "Very clean," the young lady in her mid 20s was quite happy with the dental work.  This would probably be her companion when she was growing up. I did not ask her. And the man must be her boyfriend or significant other accompanying her to the vet? I am glad that the butterfly of love had not flitted away from her as there are so many single ladies in Singapore.  I must be equivalent to her old dog in human age. Time had flown by so fast for me since I graduated.  

I prescribed a brown sugar multivitamin. 24 hours later, I phoned the couple. There was considerably less shivering. If all goes well, the stitch in the right eyelid would dissolve in 14-28 days and we would know whether the right eyeball is OK. This dog will live to old age of 15-20 years if it does not have any infections.  It probably has grown up with the young lady who probably has been too busy studying.

On Dec 6, 2009, the dog came in for stitch removal. The eyeball looked all right. No more pus. No more shivering except when the dog came into the surgery. The dog was as good as gold and the couple was quite happy with the outcome.  

P.S.
An assistant must watch the anaesthesia like a hawk especially in an old dog surgery. In this case, the dog's tongue turned purplish during dental work even though anaesthesia was at 1% instead of the usual 2.0%. When the tongue turns purplish, just disconnect the tube from the anaesthetic machine rather than decreasing dose and waiting.

This is the best method as the old heart may be failing. When the dog moves a bit and the tongue turns pinkish, re-connect.

Standby for cardiac massage. Blow air into the lungs via the tube after 3 massages. Repeat till the dog breathes on its own. Simple observations and precautions prevent many anaesthetic deaths in senior dogs. Obviously, it was not possible to just do the eye operation and then the teeth later to minimise the risk. Sometimes, the owner just does not return and the poor dog still harbours the infectious bacteria from gum and tooth diseases in the mouth.