Glacier

TOA PAYOH VETS
toapayohvets.com
Focus: Small animals - dogs, cats, hamsters, guinea pig & rabbits
Date: 04 October, 2009

Toa Payoh Vets Clinical Research
Making veterinary surgery alive
to a veterinary student studying in Australia
using real case studies and pictures

2009 Case: Dermoid Surgery in a Shih Tzu
Dr Sing Kong Yuen, BVMS (Glasgow), MRCVS
Case written: 04 October, 2009

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 Cornea Shih Tzu 8 months keratectomy Toa Payoh Vets

Dermoid in right eye excised

Cornea protected by 3rd eyelid flap for 4 days. Toa Payoh Vets.

Shih Tzu, 8 months. Right eye. Dermoid in cornea excised 9 days ago. Toa Payoh Vets

Shih Tzu, 8 months. Normal left eye. No dermoid in cornea. Toa Payoh Vets

3rd eyelid flap for 4 days.

Day 9 after excision. Cornea heals well. Healing of the cornea should be completed in another 21 days.

Normal left eye

Education of Vet Technicians from Myanmar and one intern from Temasek Polytechnic in this case by using injectable anaesthestics.

Normally, I give xylazine 20 at 0.2 ml IM, gas mask isoflurane after vomiting in around 10 minutes. Then I intubate and it will be a smooth operation. However, injectable anaesthetics have a place in vet surgery too and were used in this case.

Shih Tzu 5 kg

1. Xylazine 20 at 0.2 ml + ketamine 100 at 0.2 ml in one syringe = 0.4 ml IV. (The guideline is 0.25 + 0.25 = 0.5 ml for a 5 kg dog)

2. Zoletil 50 at 0.1 ml IM after 5 minutes. Proceed to electro-incision.

3. Excellent surgical anaesthesia for <15 minutes. Time taken to set up electro-surgery equipment delayed surgery. Soon the dog's eyes start to blink under electro-incision.

4. In practices with no isoflurane gas anaesthesia, top up with 0.1 ml Zoletil IM regularly is workable.

5. I gave isoflurane gas by mask, intubate and maintain at 2-2.5% without worries of topping up injections. This surgery needs to be done carefully without the dog waking up or blinking his eye as the cornea is around 2 mm thick and any movement may rupture the cornea via electro-incision.

6. Recovery. The dog woke up smoothly as if he had a good sleep. No painful cries or struggle.

7. Advantages: No post-xylazine vomiting. No post-Zoletil stiff neck or salivation in this case though no atropine (usually 0.2 ml IM) was used.

8. Conclusion: In this case, I hope that the mentees can see that the xylazine + ketamine + Zoletil +isoflurane combination takes up more time and is not as efficient as xylazine IM + isoflurane in this surgery. But it has a place in vet surgery in certain situations like field work and the vet must be familiar with this method.

Not all vets will agree with my philosophy - minimal use of drugs for sedation to avoid reactions and shortest time to achieve surgical anaesthesia. That is why I seldom use the xylazine + Zoletil top up combination or xylazine + ketamine + Zoletil top up combination. It may cause respiratory depression. It just takes up too much time to administer top ups when the vet has to focus on a speedy surgery.

In the 2009 case, a 3rd eyelid flap and tarsorrhaphy has been done. The sutures were removed on Day 4 to open the eyelids so as to examine the cornea for infection although antibiotic eye drops were given. The sclera was acutely inflamed. By Day 9, the owner wanted the dog home. 7 more days of nursing would be better for the dog. The domestic worker was taught how to apply the eye drops. E-collar must be worn at all times for 1 month, no exposure of the eye to sunlight and breeze for the next 3-4 weeks. The dog would now enjoy a better quality of life with no irritating Dermoid in his right eye cornea.

See also: 2003 Case: Dermoid in a Shih Tzu

Toa Payoh Vets Clinical Research