Monday, April 5, 2010

11. Hamster anaesthesia query from South Korea

E-MAIL TO DR SING DATED JAN 5, 2010

Hello Dr Sing Kong Yuen,

Happy new year!
I'm very impressed "be kind to pet" of your homepage and operating small animal clinic in South Korea.
I have poor experience about exotic pets and especially anesthesia of them.
May I(as begginer) ask favor of you about pre-eminent experience at exotic medicine?
I have pyometra patient in hedgehog and scalp laceration at font head in hamster.
Could you recommend anesthesia protocol(inhalant and injectable) each.
Hamster with amputated leg by cage had been experienced irratic and deep breath, and death in anesthetic chamber. Other hamster was not maintained enough to do surgery with ketamine 40-120mg/kg only.
How do you evaluate anesthesia depth and deal with problems.
I have general patient monitor for heart rate with alligator clips and pulse oximeter.
Could I use it in rodent?
Do you usually use absorbable suture at skin and why ?


I appreciate you in advance!
Be happy and wealthy!
Keep Healthy!


Sincerely yours,


Name of Vet


E-MAIL REPLY FROM DR SING DATED JAN 6, 2010

보낸 시간: 2010년 1월 6일 (수), 5:31:38 AM
제목: Re: Hamster and Hedgehog anesthesia in Korea

I am Dr Sing from Singapore, not from South Korea. My surgery is www.toapayohvets.com. I don't have hedgehog patient. The following applies to dwarf hamsters mainly. For Syrian hamsters, the same principles of close observation apply.

For sick dwarf hamsters needing surgery, I use isoflurane gas anaesthesia (plastic container) at 5% for around 1 minute, but close observation of the hamster is the key to success.

In other cases of healthy hamsters for tumour removal, I use Zoletil 50 as little as 0.01 ml IM as sedation. Then I use 5% isoflurane gas for less than 20 seconds and take out the hamster from the gas container to operate. If the hamster moves, I repeat the gas anaesthesia. Then I take it out to operate. Operation room must be warm to prevent hypothermia. If you have a cold operating room, you need to reduce the temperature or switch off the air conditioning during surgery. Hamster should be as dry as possible.



In this way, I maintain the surgical anaesthesia to operate. Most surgeries are less than 10 minutes. I have not used ketamine or other injectable anaesthesia except Zoletil on dwarf hamsters, so, I cannot share my experience with you.

Surgical anaesthesia levels are very difficult to assess in the dwarf hamster unlike in the dog and cat. Close observation of starting eyelid closure, movement and breathing rate is extremely important as there is a very high risk of anasthetic death if the vet does not know what he should observe or being too busy doing surgery.

You may need to have a very good veterinary assistant to help you observe the anaesthesia while you do surgery. But you should be able to know too when the hamster moves.

I don't know whether you can use pulse oximeter on dwarf hamsters. I use absorbable 6/0 or 7/0 sutures to stitch the hamster's skin so that owners don't need to come back for suture removal.

I hope this e-mail answers your questions.


E-MAIL TO DR SING DATED JAN 6, 2010
Subject: 답장: Hamster and Hedgehog anesthesia in Korea
To: "David Sing"


Dear Dr David Sing,

Thank you so much for your help!
How long can you maintain hamster with Zoletil 0.01ml im ?
At recovering anesthesia, how do hamsters act ?
At gas anesthesia, if depth of anesthesia is decreased and hamster could move, you put hamster in plastic container again.
Did you use continously anesthetic machine with nose cone described Saunder's manual of small animal practice?
What's there merit or demerit of continous or intermittent gas anesthesia.
Do you prefer intermittent gas anesthesia because of some reason or not ?
I considered aceromazine sedation, ketamie sedation, ketamine/xylazine anesthesia, zoletil anesthesia, and gas anesthesia
but I didn't successfully experience them.


I'd appreciate once more you in advance!

PS) I added photocopy of Saunder's manual of small animal praqctice and exotic animal formulary.

Best regards,


E-MAIL FROM DR SING DATED MAR 6, 2010

Thank you for your email. Now, I have time to reply to you. See below.


How long can you maintain hamster with Zoletil 0.01ml im ?
LESS THAN 2 MINUTES


At recovering anesthesia, how do hamsters act ?
SMOOTH QUIET RECOVERY AS IF THEY JUST WAKE UP


At gas anesthesia, if depth of anesthesia is decreased and hamster could move, you put hamster in plastic container again.
YES, I PUT INTO PLASTIC CONTAINER AND GIVE ISOFLURANE GAS FOR A FEW SECONDS.


Did you use continously anesthetic machine with nose cone described Saunder's manual of small animal practice?
NO


What's there merit or demerit of continous or intermittent gas anesthesia.
I THINK CONTINUOUS GAS ANAESTHESIA IS TOO RISKY FOR HAMSTER. DEPENDS ON YOUR DOSAGE.

Do you prefer intermittent gas anesthesia because of some reason or not ?
INTERMITTENT PREFERRED FOR ME. NEED CLOSE OBSERVATION OF HAMSTER'S STAGE OF ANAESTHESIA AND SHORT DURATION.


I considered aceromazine sedation, ketamie sedation, ketamine/xylazine anesthesia, zoletil anesthesia, and gas anesthesia
but I didn't successfully experience them.
DO YOU YOU USE ZOLETIL ANAESTHESIA?



I'd appreciate once more you in advance!



E-MAIL TO DR SING DATED MAR 6, 2010
Thanks you very very much !


P.S. Singapore government prohibits exotic pets. So, I don't get hedgehogs or reptiles. 99% of my hamster cases are dwarf hamsters nowadays!

INFO FROM SOUTH KOREA VET
Saunder's manual of small animal practice and exotic animal formulary
INJECTABLE ANAESTHETIC DRUGS FOR POCKET PETS

For hamsters

1. Acepromazine sedation 0.5 to 1.0mg/kg IM
2. Ketamine/xylazine anaesthesia 50-100mg/kg (ketamine) and 10mg/kg (xylazine) IP.
Wide dosage ranges are due to marked individual variations. Use lower dosages first.
3. Zoletil (tiletamine and zolazepam) anaesthesia 20-40mg/kg IM for chinchilla and rats. No mention about use in the hamster.
4. Zoletil/xylazine combination. 30mg/kg (Zoeltil) and 10mg/kg(xylazine) IM or IP
5. Isoflurane. Anaesthesia of choice for all pocket pets. 2.5% induction. 0.25% - 4% for maintenance.


I don't have experience using the above in my dwarf hamster anaesthesia and therefore am unable to comment except for isolfurane. All these formulae about 2.5% induction and maintenance are not much help. The vet has to go back to the fundamentals of the stages of anaesthesia and that is quite difficult for the hamster unlike the dog and cat. Be vigilant and be very careful even if you use isoflurane gas via mask. I don't do it.

ZOLETIL ANAESTHESIA FOR DWARF HAMSTERS AT TOA PAYOH VETS.
Over the last 5 years, around 100 dwarf hamsters had been operated using the following dosage of Zoletil 50.

For 4th year vet students, the details are as follows:

An adult dwarf hamster weighs around 40g.
Using the above, paragraph 3 --- Zoletil (tiletamine and zolazepam) anaesthesia 20-40mg/kg IM for chinchilla and rats. No mention about use in the hamster.

Let's calculate the dosage for the hamster weighing 40g.
The dosage should be (using lowest dosage of 20mg/kg) 20mg/1000g. This will be 0.8mg for 40g. Zoletil 50 is 50 mg/ml. Therefore, the volume of Zoletil 50 will be calculated as 0.01 ml at 0.5mg. For the 40g dwarf hamster, the volume should be a bit more than 0.01 ml at 0.015ml. However, 0.01ml was effective for less than 2 minutes of anaesthesia. For Syrian hamster, this volume was insufficient. I use 0.02 ml IM. In my practice, no anaesthetic deaths occur at this dosage. Isoflurane gas maintenance (intermittent) may be necessary when surgery exceeds 2 minutes.

Obviously the vet will not get any referral from hamster owners if he or she gets anaesthetic deaths frequently, unless the owner has no choices. Dwarf hamster anaesthesia is a particularly heart-breaking worrisome time but if the vet produces good clinical outcomes, it can be very satisfying to see the little creature alive with no more nasty tumours or wounds from bites. What the owner wants is a hamster alive from the vet. No excuses. Don't use a variety of drugs for hamster anaesthesia as you don't become competent. That is why I use Zoletil 50 or 100 only.

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