22. Injectable Anaesthetics - Dogs + Cats - Siem Reap, Cambodia

Thursday, Jan 14, 2010. I visited The No. 1 Animal Place, 645 Hup guan Street, Siem Reap, Cambodia today. I thought it was a pet shop with fishes, birds, rabbits and hamsters for sale. Puppies and kittens are never sold here. The operating room is upstairs. The following is practical anaesthetic knowledge shared by an English lady vet graduated from London. She practised for one year in Siem Reap.

DOGS
Xylazine 2% 0.05ml/kg
Ketamine 5% 0.3 ml/kg (human ketamine is 5% i.e. 50mg/100 ml unlike veterinary ketamine which is available as 10%).
Separate syringes, one injection another instead of waiting 15 minutes as this was found to be more effective. IM injection.
Onset 10-15 minutes (to sleep)
Duration 20-25 minutes (before topping up)
Top up: Mix above 2 drugs in one syringe and give at half dose.

CATS
Xylazine 2% 0.1ml/kg
ketamine 5% 0.2 ml/kg
Both drugs in one syringe
Onset 5 minutes
Duration 45 minutes
Top up: Mix 2 drugs in one syringe and inject.
Disadvantage: Wakes up suddenly. Wait 5 minutes before proceeding to surgery. Takes a long time to wake up. Vomiting. Tends to vomit with dogs and cats even on empty stomachs. For sick cats, the dosage is reduced by 1/3.

REVERSAL
Yohimbine use in cats to wake them up sooner. No need to use in dogs in her cases. Rapid recovery was obtained with Yohimbine in cats in her experience. Is it possible that her xylazine dosage was higher such that the cats take a longer time to be mobile? See Discussion below.

DISCUSSION
CATS around 2 kg in Singapore Toa Payoh Vets, www.toapayohvets.com
I use Xylazine 2% @ 0.1ml and Ketamine 10% @ 0.4 ml in one syringe IM
Onset 5 minutes
Duration 20 minutes

Comparing this to the English vet's formula, she would use
Xylazine 2% @ 0.2 ml
Ketamine 5% @ 0.4 ml (Since I use 10%, this would be equivalent to 0.2 ml)
Her dosage permits her a longer duration of 45 minutes. She needed 15 min pre-op. She needed a reversal drug which i don't need.

That meant she used xylazine 2% @ 0.2 ml and ketamine 10% @ 0.2 ml while I used xylazine 2% at 0.1 ml and ketamine 10% at 0.4 ml.

DOG, 5 kg Jack Russell
Xylazine 2% @ 0.25 ml IM
Ketamine 5% @ 1.5 ml IM (For me, it should be 0.75ml for 10% ketamine I use).
Worked very well for her. Recovery is smooth.
Separate syringes.
Ketamine 1.5 ml is large amount. It stings and is painful for dog. Dog bites. Muzzle dog.
Top up, use one syringe.

As I don't use above for dogs, I am happy to receive her valuable feedback. I use Xylazine 2% at 0.2ml IM, Wait 5-10 minutes and gas mask isoflurane and intubate.

RABBIT
In a practice in England, the following is used for anaesthesia, according to the English vet:

Domitor 0.1 mg/kg
Ketamine 10% @ 10mg/kg
Torbugesic 0.5mg/kg
In one syringe.
Need to monitor rabbit. Stops breathing. Give reversal Antisedan.

Rabbits do not need to be starved prior to anaesthesia unlike dogs and cats since they are incapable of vomiting and the most common post-op problem is intestinal stasis. They should be given hay as soon as possible to prevent post-operative ileus or gut stasis.

Sedation
Domitor 0.1 mg/kg
Ketamine 10% @ 5mg/kg
Torbugesic 0.5 mg/kg
In one syringe.

NOTES: Torbugesic (butorphanol) produces additive effects when used with other sedative or analgesic drugs. In horses, 0.1 mg of butorphanol/kg IV is recommended for the alleviation of visceral pain. Ketamine is a dissociative drug that is analgesic and does NOT depress cardiovascular function. Xylazine causes muscle relaxation, sedation and analgesia.

Molar spur trimming (injectable anaesthesia sufficient without gas anaesthesia.
A common drug combination in rabbit anesthesia is butorphanol (Torbugesic) and midazolam (Versed). Butorphanol is an opiod with analgesic (pain-killing) and sedative properties. Midazolam is related to diazepam and produces sedation and muscle relaxation. Anaesthetic induction can be gas or a combination of ketamine, midazolam and xylazine. Propofol is a new drug that is expensive but relatively safe. It is not known how it works.

Spaying and neutering are not popular in Siem Reap in 2009. The majority of the locals don't vaccinate, spay or neuter nor feed commercial dog food. Parvovirus is rampant from puppies imported from Thailand. The small animals at this Shop is part of the business model to get clients coming in. In Singapore, it will not be permitted if there is no separate entrance for the pet shop and vet surgery premises. A thriving fully equipped vet practice in Phnom Pem has been started by a French vet for many years.

In countries like Cambodia and Myanmar, it may be too expensive to set up a gas anaesthesia machine for small animals. Therefore injectable anaesthesia is commonly used by the local vets.