Centrally acting analgesia in horses?

[Jimbol]

When a vet performs routine procedures such as geldings, stitch ups and tooth removals etc on your horse which may result in a certain amount of pain, would you prefer the vet to use a centrally acting analgesic to prememptively remove any pain during the proceedure even if it cost a arounmd £15 or so more?

It si also worth noting that this practice is standard in small animals.

 

[Jimbol]

When i refer to centrally acting analgesia i am refering to an opiate such as morphine or bupranorphine as used in small animals and humans.

 

[blitznbobs]

As a specialist in human pain relief, I am all for analgesia. If vets were good at peripheral blocks then I am of the belief that this offers the best pain relief... It is what I would choose as a human patient. But if this is not possible then opiates are always the way to go. Altho I'm not a fan of bupernorphine as it's a ***** drug ... Stick with old fashioned morphine and u won't go far wrong.

 

[misst]

I cannot answer as I do not know the risks involved. Provided there are no higher risk then I would happily pay extra for my horses to have pain relief, but only if the pros and cons were explained and I could give informed consent.

 

[Jimbol]

buprenorphine is a great drug and the main one used in small animal practice, the problem is the presentation made by Ricketts in the 70's was awful.

Dose for dose to about 130 miicrgrams per kilo you get similar levels of analgesia between morphine and bupranorphine the difference is that the partial agonist aspect will make it plateau where morphine will continue till we get respiratory depression. Buprenorphine is becoming more popular in human use in India and the far East.

An opiate is also useful in potentiating the sedation and smoothing the curve.

 

[Jimbol]

I cannot answer as I do not know the risks involved. Provided there are no higher risk then I would happily pay extra for my horses to have pain relief, but only if the pros and cons were explained and I could give informed consent.

Your vet is likely goiong to be using butorphinol at a sedative dose, this offers almost no pain relief and is infact a more risky product than the new alternative.

 

[Jimbol]

As a specialist in human pain relief, I am all for analgesia. If vets were good at peripheral blocks then I am of the belief that this offers the best pain relief... It is what I would choose as a human patient. But if this is not possible then opiates are always the way to go. Altho I'm not a fan of bupernorphine as it's a ***** drug ... Stick with old fashioned morphine and u won't go far wrong.

Morphine can also cause problems with gut motility which is a greater issue in horses than it is with humans, this does not appear to be the case with buprenorphine.

 

[misst]

If there is a safe alternative that offers good analgesia I would be more than happy to pay extra. Hope that helps
I just would not go in "blindly" with products that I have no knowledge of. My vet, would, I assume explain alternatives and pros and cons of each type of drug so we could reach an informed choice.

 

[blitznbobs]

I will remain not a fan of buprenorphine... there are better analgesics out there. (It may be wonderful in vet medicine where situations don't get quite as complex as they do in human medicine) and I do prescribe the patches to be used as a long acting painkiller in moderate pain situations (where scaling up... isn't likely to be necessary but when you are 'adding' drugs together to get the best drug profile the partial agonist effect can become more agonist than not and thus the pain relief that should be present with a drug used in conjunction with buprenorphine (eg oxycontin etc) just isn't as efficacious as you thought it might be... So adding a short to a longer acting analgesic (if using buprenorphine) becomes more difficult and can actually reduce the amount of analgesia one experiences. I accept that the gut motility issues are probably not cured with the odd laxative in horses...

People tend to complain more if their pain ain't controlled so we tend to use a combination of several analgesics (even for 'minor' procedures) and I'm not sure how many blokes would see gelding as a minor procedure!!

30 years ago - it was thought that analgesia in babies was 'unnecessary'... makes you think, doesn't it?

BnBx

 

[Jimbol]

If there is a safe alternative that offers good analgesia I would be more than happy to pay extra. Hope that helps
I just would not go in "blindly" with products that I have no knowledge of. My vet, would, I assume explain alternatives and pros and cons of each type of drug so we could reach an informed choice.

Does your current vet explain what drugs they are giving and why? if the vet explained the side effects of bute i am sure many owners will be a lot less liberal in administering it.

 

[martlin]

I thought that Torbugesic, which my vet routinely uses together with Domosedan is a rather potent analgesic... and Torbugesic is buterphanol.

 

[misst]

Does your current vet explain what drugs they are giving and why? if the vet explained the side effects of bute i am sure many owners will be a lot less liberal in administering it.

Yes he does! And we have always been very aware of the problems bute can cause. I like my vet practice because they always explain first and give choices to us.
That is why I said I would want to discuss it with my vet and would be reluctant to give consent for something I had no understanding of. As I said "informed consent" is the key. In priniciple I would pay a lot extra for my horses comfort if I was persuaded of its efficacy and safety.

 

[misst]

30 years ago - it was thought that analgesia in babies was 'unnecessary'... makes you think, doesn't it?

Blitznbobs I remember this too (only just) - being told that babies, especially premature ones, did not feel pain during procedures Times do change - and mostly for the better.

 

[Jimbol]

I will remain not a fan of buprenorphine... there are better analgesics out there. (It may be wonderful in vet medicine where situations don't get quite as complex as they do in human medicine) and I do prescribe the patches to be used as a long acting painkiller in moderate pain situations (where scaling up... isn't likely to be necessary but when you are 'adding' drugs together to get the best drug profile the partial agonist effect can become more agonist than not and thus the pain relief that should be present with a drug used in conjunction with buprenorphine (eg oxycontin etc) just isn't as efficacious as you thought it might be... So adding a short to a longer acting analgesic (if using buprenorphine) becomes more difficult and can actually reduce the amount of analgesia one experiences.



BnBx

The levels where it antagonises itself is about 14 times the higher dose licenced in horses and 7 times that in dogs and cats.

 

[lauraandjack]

Buprenorphine also has popularity in the veterinary world because it is at a lower controlled level than morphine (because it has slightly less potential for dependent abuse), and therefore involves less paperwork and less stress for us vets (it's not a lot of fun being legally responsible for drugs which are subject to abuse by humans).

Butorphanol is usually the favourite for sedation purposes in animals as it has strong sedative actions. It is not a great analgesic, although it is good for abdominal pain (e.g. colics). Buprenorphine is better for analgesia, but not so good for sedation, it also takes longer to take effect, so not so good when you want sedation asap.

 

[Jimbol]

Yes he does! And we have always been very aware of the problems bute can cause. I like my vet practice because they always explain first and give choices to us.
That is why I said I would want to discuss it with my vet and would be reluctant to give consent for something I had no understanding of. As I said "informed consent" is the key. In priniciple I would pay a lot extra for my horses comfort if I was persuaded of its efficacy and safety.

Who is your vet? or if you do not like to say, what county?

 

[blitznbobs]

The levels where it antagonises itself is about 14 times the higher dose licenced in horses and 7 times that in dogs and cats.

Interesting... we don't tend to have 'top doses' of opiates in humans you can go as high as you like!

BnB

 

[Jimbol]

Buprenorphine also has popularity in the veterinary world because it is at a lower controlled level than morphine (because it has slightly less potential for dependent abuse), and therefore involves less paperwork and less stress for us vets (it's not a lot of fun being legally responsible for drugs which are subject to abuse by humans).

Butorphanol is usually the favourite for sedation purposes in animals as it has strong sedative actions. It is not a great analgesic, although it is good for abdominal pain (e.g. colics). Buprenorphine is better for analgesia, but not so good for sedation, it also takes longer to take effect, so not so good when you want sedation asap.

both drugs have similar onset of sedation, buprenorphine tends to have no sedative effect when not given with a sedative however, vets prefer torb mainly because you can use a small dose for sedation and is therefore cheaper.

Morphine has no veterinary licence, and tends to make dogs a cats vomit which is not good for tubing.

 

[blitznbobs]

FAscinating thread... as a total aside do you guys still use ketamine as an anaesthetic agent -- cos this is coming back in human medicine with some good results.

B

 

[lauraandjack]

Jimbol as a practising vet I have to disagree with you about the onset of action of buprenorphine. Granted I have never used it in horses, but certainly in small animals it has a noticeably longer onset of action than butorphanol when given for pre-medication or sedation purposes.

Bitsnbobs - yes ketamine is still a popular anaesthetic agent certainly in the equine side of things. It's very useful as a short acting GA agent, one bolus generally gives you sufficient duration of surgical anaesthesia for a routine castration, and you can give a couple of top ups for slightly longer procedures. It's also used as an induction agent prior to gaseous maintenance. Nice and safe when you are in a field situation and don't have the benefit of oxygen supplementation etc.

 

[Jimbol]

Jimbol as a practising vet I have to disagree with you about the onset of action of buprenorphine. Granted I have never used it in horses, but certainly in small animals it has a noticeably longer onset of action than butorphanol when given for pre-medication or sedation purposes.

It could be that Torb is often associated with Dom where as buprenorphine with ACP. In horses we found sedation sets in very quickly with a very smooth recovery, ataxia was also less common which can be an issue with Torb.

 

[Jimbol]

it is interesting L and J because the equine vets are in a position small animal vets were around 15 years ago in regards to pain control

 

[Wishful]

Presumably the major issue is that horses have more anaesthetic issues than humans or small animals (other than rabbits, which are apparently very prone to dying under anaesthetic... and cope best if considered as small horses...???)

Given that in colic surgery, one of the major causes of death (when the horse actually makes it through the surgery) is the guts not restarting, it would make sense to avoid giving any drugs that even have a marginal effect on the GI system. Equally with the known breathing issues (especially now halothane is becoming less available) drugs which have known potential negative effects on the respiratory system might also be considered not worth the risk.

Horse anaesthetics have a fairly horrendous (in the context of human medicine) survival rate, so I would imagine that systemic pain relief needs to be balanced against the potential reduction in survival rates.

 

[Jimbol]

Pain is a contributing factor to disease, and although survival rates in anaesthetic for horses is poor the greater area of issue is in the quality of recover, this can only be enhanced with pre-emptive analgesia. However the greatest area of interest is in the standing sedation aspect of equine medicine as this is the more common practice.

When researching the licence for buprenorphine there were no noticable changes in horses normal fecal output whilst the drug was administered, you will infact find that there are more associated risks with the sedative and anaesthetic agents than there are with the opiate and the opiate will reduce the levels of the other drugs.

The real issue with colic is whether a horse will be better off recieving opiate analgesia prior to surgery, as this should improve survival before during and after surgery.

 

[Jimbol]

I thought that Torbugesic, which my vet routinely uses together with Domosedan is a rather potent analgesic... and Torbugesic is buterphanol.

Butorphanol offers little analgesia, in order to acquire the anlgesic level the vet will increase the dose by 4 times that used for sedation, even then the analgesia will only last for 2-3 hours.

In a study done gelding 10 new forest ponies with Butorphanol and domosedan all the ponies required post operative analgesia (NSAID) 1-2 hours after the sedation, with buprenorphine done in a seperate stude with 10 new forest ponies this was not the case and normal eating, drinking and socialising behaviour resumed quickly after the proceedure.

 

[Jimbol]

has anyone had an issue with replacing dressings or touching an area where a proceedure has been performed.

 

[martlin]

has anyone had an issue with replacing dressings or touching an area where a proceedure has been performed.

What sort of issues, and what sort of procedure have you got in mind?

 

[Jimbol]

when pre-emptive centrally acting analgesia is not used the pain cycle can be amplified and create a cycle called the wind-up effect, this can cause a pain reaction even when pain is not neccessarily there.

For example i had a horse who had a growth removed from the ear and after that proceedure putting his bridle on became a real challenge. Also with a gelding who will now react when you touch around his tail where before being gelded he was fine.

 

[blitznbobs]

So is TIVA (total intravenous anaesthesia) used in vet medicine yet or is it too risky. (We use it in humans now as it gives a lovely smooth anaesthesia without the vomiting nausea issues of Sevoflurane)...

It facinates me where human medicine is different (both ahead and behind of vet medicine) so please excuse my interogation!

BnBX

 

[martlin]

ah, ok.
No, I have not experienced that type of problems. The only problems with changing dressings etc I have experienced is that I am yet to meet a vet who can properly bandage a horse.