Wednesday, July 15, 2009

23. Spaying stray cats in Singapore

Caterwauling cats x 2

Cat 1. Around 6 months
Jul 3, 09. Caterwauling. Owner got Ovarid. Gave Ovarid 20 mg x 1. 1/4tab/day x 4 days.
Jul 12, 09. Spayed.
3.2 kg
Xylazine 20 @ 0.1 ml, Ketamine 100 @ 0.4 ml in one syringe IM
Insufficient time, cat growled. Top up isoflurane gas 5% for < 1 minute
Ovaries - Yellow corpus luteum.

Cat 2. Around 6 months
Jul 6, 09. Caterwauling 7 days ago.
Jul 13, 09. Spayed.
3.65 kg
Xylazine 20 @ 0.15 ml, Ketamine 100 @ 0.5 ml in one syringe IM
Excellent anaesthesia. I took note of the time for surgery in this case.

2.40 pm Injection xylazine & ketamine. Clipping after 3 minutes.
2.47 pm Incision started.
3.16 pm Skin suture (horizontal mattress) completed.
Duration: 29 minutes.

Surgery not under pressure as Cat 2 is in excellent anaesthesia.
Ovarian blood vessels large as in Cat 1. Around 3 mm in diameter
Uterine blood vessels around 3 mm in diameter
Ligate ovarian bv. Double ligate uterine body. In Cat 1, I had to transfixed ligature as well as double ligate the uterine body.

Ovaries - One cystic ovary?

Delays are caused by:
1. Too much time is spent in waiting (> 5 minutes in Cat 1 for the cat to be sedated before clipping hair and preparing the site for surgery).
2. Incorrect restraint. Experienced assistant like James Ang tended to forget the proper procedure. The correct restraint here is to hold the cat upwards by the scruff of the neck. I asked him to lift the cat off the table. I injected IM. There was no reaction from the injection unlike Cat 1. In Cat 1, James positioned incorrectly, gripping the cat on the table with his right hand across the shoulder of the cat from the right side of the cat, instead of being on the left side of the cat., so that his grip was not firm. The cat moved as I injected 60% of the anaesthetic. He got scratches on his hand, in earlier case of another cat spayed by Dr Teo.

Fierce stray cats
How to inject such cats?
1. Put cat inside small crate. Put telephone books and other books to push him into corner. Tilt the crate. Inject IM when the cat is distracted. Not really ideal as some cats reacted first during injection. Xyalzine 0.2 ml IM in local Singapore cats would be easy and quick for injection, but not the larger amount in xylazine:ketamine combinations. Isoflurane via gas mask is used in cases where xylazine 0.2 ml is given.
2. Lasso held the cat's pelvic area and back towards side of crate. Inject IM.
3. Do not give 2nd injections if the vet missed or gave insufficient amount as the cat may die of heart failure due to the stress. Postpone surgery to another day.

My assistant James said that I had performed the surgery faster in Cat 2. The dosage of injectable anaesthesia for cats 3.5 - 4 kg kg should be that for Cat 2.

The cat below was not spayed by me.

No comments: