Acepromazine in Boxers

[sofficat]

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How many of you work at a clinic who uses ace in boxers?
How many forbid it?
What is your experience with it?
Does anyone know WHY people don't like to use it? Really WHY? (Like a true study, not just hear say).

Thanks!!

 

[cowgirla]

How many of you work at a clinic who uses ace in boxers?
How many forbid it?
What is your experience with it?
Does anyone know WHY people don't like to use it? Really WHY? (Like a true study, not just hear say).

Thanks!!

We tend to avoid injectable Ace at all costs, no matter what the breed. We've got a couple psychos that do get it orally though.

We were using it up until about a year and a half ago, on ear crops. Vet who did ear crops left, and so did the Ace

But even then, it was never used on boxer puppies. Just the dobes/pits/mastiffs.

I think boxers usually got Ket/Val, although I might be remembering that wrong.

Doesnt it cause first degree heart block in boxers?

 

[deleted266066]

How many of you work at a clinic who uses ace in boxers?

I have nothing productive to add. But when reading the title of the thread I totally was thinking "boxers" as in... men's undergarments? hahaha. It's been a long day.

Carry on 🙂

 

[Whyevernot55]

We generally don't use Ace EVER except sometimes for sedating euthanasias. I've heard that it causes heart problems in boxers, but no evidence to back that.
I personally don't like it because of the side effects it causes in horses, but that's irrelevant!

 

[natalieises]

I have nothing productive to add. But when reading the title of the thread I totally was thinking "boxers" as in... men's undergarments? hahaha. It's been a long day.

Carry on 🙂

I would neither advise against or for administering ace while wearing only boxers

 

[HopefulAg]

I think the only evidence is hear-say at the moment. I've heard lots of it, but never seen a study on it, in either JAVMA or PubMed (though there is some stuff about Ace in general on dogs).

 

[sofficat]

We tend to avoid injectable Ace at all costs, no matter what the breed. We've got a couple psychos that do get it orally though.

We were using it up until about a year and a half ago, on ear crops. Vet who did ear crops left, and so did the Ace

But even then, it was never used on boxer puppies. Just the dobes/pits/mastiffs.

I think boxers usually got Ket/Val, although I might be remembering that wrong.

Doesnt it cause first degree heart block in boxers?

What do you use to sedate? Ket/Val is administered IV, so I wouldn't imagine that would be your sedative.
As far as causing heart blocks- no.

 

[cowgirla]

What do you use to sedate? Ket/Val is administered IV, so I wouldn't imagine that would be your sedative.
As far as causing heart blocks- no.

I think the last time we gave an animal a premed before anesthetizing was with the ear crops. We seem to rarely do it now, just start off with IV anesthesia/propofol.

So if it wasnt Ket/Val, I don't remember what we used for boxers! I just know that we didn't give them the ace the others generally got. They stopped doing ear crops not long after I started there.

For boxers, I've always been told that it drops their heart rate. I thought someone told me that it was first degree heart block, but apparently not.

ETA: And when I google it now, I found quite a few sites that say first degree heart block. Granted, they arent exactly scientific sites, mostly boxer rescues.


ETA 2: Ket/Xylazine, maybe? I know it had ketamine in it, as the sedation for boxers.

 

[marycatherine]

I have nothing productive to add. But when reading the title of the thread I totally was thinking "boxers" as in... men's undergarments? hahaha. It's been a long day.

Carry on 🙂

I thought this, too!

 

[eventualeventer]

Whyevernot, are you referring to hypotension or penile paralysis?

Wouldn't you want boxers to stay put and not move too much?

 

[BarnyardPunch]

How many of you work at a clinic who uses ace in boxers?
How many forbid it?
What is your experience with it?
Does anyone know WHY people don't like to use it? Really WHY? (Like a true study, not just hear say).

Thanks!!

At a high volume S/N clinic I used to work at, we gave every dog coming in Ace IM except any dog that had a history of seizures.

I was under the impression that the Boxer thing was based on anecdotal evidence and there were no actual studies concluding they are more sensitive to the drug. I could totally be wrong on that though.

 

[chii chan]

Where I work, the main surgeon uses ace/atropine and torb (all SQ) for pre-anesthetic drugs. Then we mask down with isoflurane. In older animals, she doesn't use ace. Only exception is male cats get ket/val (IV) to be knocked out for neuters. The other doctor who only sometimes does surgery uses torb only. They both graduated from UC Davis within a couple years apart from each other (about 20 years ago).

I have no input on the Boxer thing from a scientific standpoint, but the first thing I thought of was heart issues with the ace. However, I've never really paid attention to whether or not the doctor has ever used it in a Boxer. (I would assume not?)

 

[Tobysgirl81]

We use ace fairly liberally in older dogs and brachicephalic - usually mixed with some sort of an opioid - for sedation. I'm pretty sure I've given it to a fair number of Boxers, and certainly have never been told NOT to give it to them. And honestly, with the number of people we have around here who read journal articles All.The.Time. I'm sure at least one of them would have popped up with "Well I have an article about that" by now.

Ket/Val CAN go IM, it just burns like hell and takes a little longer to work. Ket in general burns like the dickens, so keep that in mind whenever you use it in clinics kiddios 😉 It's usually used as an inducition agent IV, but can be very heavy sedation IM as well.

 

[critterfixer]

Our cardiology professor told us she does not use Ace in Boxers (or Dobies). Mainly I think it is because they tend to have occult cardiomyopathy, and in boxers it presents with ventricular premature contractions more often than in other breeds. Acepromazine can cause sinoatrial arrest, and thus lead to VPCs. In a dog that might already be having undetected VPCs, this can theoretically cause the heart to go into fibrillation and lead to acute collapse.

 

[Whyevernot55]

Whyevernot, are you referring to hypotension or penile paralysis?

Wouldn't you want boxers to stay put and not move too much?

I was thinking more of penile paralysis, but that's because it was the end of a VERY long week and my brain is functioning at barely gutter level.

As an aside, we typically use DexDomitor/Ket/Torb or some combination thereof IM for pre-anesthetic injection, induce with Ket/Val IV if necessary - most of the time they're zonked enough to tube and put on inhalant from the pre-an. We've seen bad reactions to some stuff though - yesterday an 8mo English Setter in for a neuter had a seizure after the pre-an and spent the rest of the day being babysat because the ketamine made him hyperreactive.

 

[sofficat]

For boxers, I've always been told that it drops their heart rate. I thought someone told me that it was first degree heart block, but apparently not.

ETA: And when I google it now, I found quite a few sites that say first degree heart block. Granted, they arent exactly scientific sites, mostly boxer rescues.

Ace causes a decrease in heart rate in all dogs, not just boxers (and decrease in blood pressure).
There's never been any studying showing that it causes 1st degree heart block (which usually is asymptomatic and pointless to treat). Pretty much all boxer rescues will tell you to never ever use ace and you are exactly right- they are not scientific sites and notice they don't reference any studies or even clinical trials.

 

[sofficat]

At a high volume S/N clinic I used to work at, we gave every dog coming in Ace IM except any dog that had a history of seizures.

I was under the impression that the Boxer thing was based on anecdotal evidence and there were no actual studies concluding they are more sensitive to the drug. I could totally be wrong on that though.

👍

I started this thread because I have ALWAYS heard to NEVER give ace to any boxers (or even boxer mixes) and I never really knew why (except the whole 'it stops their heart and kills them' explanation). Then we learned how that is not true and there has been zero studies proving it does anything different to boxers. So I was wondering what others have heard.

 

[eventualeventer]

Sofficat, I really enjoy your educational threads. Thanks for leading the discussion!

 

[Tobysgirl81]

I was thinking more of penile paralysis, but that's because it was the end of a VERY long week and my brain is functioning at barely gutter level.

As an aside, we typically use DexDomitor/Ket/Torb or some combination thereof IM for pre-anesthetic injection, induce with Ket/Val IV if necessary - most of the time they're zonked enough to tube and put on inhalant from the pre-an. We've seen bad reactions to some stuff though - yesterday an 8mo English Setter in for a neuter had a seizure after the pre-an and spent the rest of the day being babysat because the ketamine made him hyperreactive.

Holy crap, no doubt they're knocked out on that combo as a preanesthetic! We refer to that as our "kitty bomb" at work, and use it to knock the ish out of our feline patients if we have to do something seriously uncomfortable to them.

I think the craziest I saw was with a baaaaaaaaad JRT mix who had a fractured jaw. We needed to take radiographs and he was a nasty little cuss who would bite you as soon as you thought about touching him. Talked to the anesthesiologist who recommended 1 mg/kg of Morphone (yes, you read that right). Dog was DOWN for the count. It was great. Unfortunately, he woke up much sooner than we needed him to and we ended up placing a catheter and using propofol to keep him down a little longer while we pulled a wire. But hot dang, never knew you could give that much morphine! Not suggesting it, just saying it was crazy. I suppose, the real benefit is that if something had have happened it COULD be reversed too.

Man, I've been in vet med too long. I was just thinking about a horse who had a bad reaction to (I believe) valium. He just went bonkers on us...ran all over the farm, jumped through the front of a golf cart, broke a fence...It was just crazy. Ended up with minimal bruising and a handful of superficial scratches only.

 

[Doxorubicin]

How many of you work at a clinic who uses ace in boxers?
How many forbid it?
What is your experience with it?
Does anyone know WHY people don't like to use it? Really WHY? (Like a true study, not just hear say).

Thanks!!

I've heard of a clinic here in town using it for boxers, but I don't know if it's true or not. Two of my family's friends have lost boxers to anesthesia; not sure if the agent was ace or not, but they both went to the clinic reputed to use it in boxers.

 

[sofficat]

I think the craziest I saw was with a baaaaaaaaad JRT mix who had a fractured jaw. We needed to take radiographs and he was a nasty little cuss who would bite you as soon as you thought about touching him. Talked to the anesthesiologist who recommended 1 mg/kg of Morphone (yes, you read that right). Dog was DOWN for the count. It was great. Unfortunately, he woke up much sooner than we needed him to and we ended up placing a catheter and using propofol to keep him down a little longer while we pulled a wire. But hot dang, never knew you could give that much morphine! Not suggesting it, just saying it was crazy. I suppose, the real benefit is that if something had have happened it COULD be reversed too.

The regular dose for morpine is .5-2 mg/kg, so you could have doubled your dose and still be withing range. But let me guess, do you work at Banfield? Plumbs also says that doses at 100mg/kg are thought to be fatal... so you could have quadrupled your dose and your patient would have lived.
"The only way to kill a dog with morphine is to shove the bottle down their trachea" 😀

 

[Tobysgirl81]

No, I don't work at Banfield. I guess, we normally work within ranges of .1 to .25 mg/kg and see pretty decent sedative effects. Of course, we normally mix it with something like ace or another sedative, so we don't need to use the .5 to 2 mg/kg dose. Just goes to show, whatever you're used to and comfortable with is what you think is correct!

 

[critterfixer]

👍

I started this thread because I have ALWAYS heard to NEVER give ace to any boxers (or even boxer mixes) and I never really knew why (except the whole 'it stops their heart and kills them' explanation). Then we learned how that is not true and there has been zero studies proving it does anything different to boxers. So I was wondering what others have heard.

It's not that the drug is different in boxers, it's that boxers are different. They don't tend to show their heart disease until they collapse. So you are correct that Acepromazine does not "do anything different to boxers." BUT boxers are more likely that other breeds to have an underlying cardiomyopathy making them more sensitive to the effects of acepromazine.

Boxers and Dobermans have a MUCH higher incidence of occult cardiomyopathy than other breeds:
http://www3.interscience.wiley.com/journal/121527251/abstract?CRETRY=1&SRETRY=0

"Retrospective report on the signs of dilated cardiomyopathy in 369 dogs in the UK:
History & Signalment of the dogs seen at a referral cardiology clinic
- purebred dog, 365 of the 369 dogs
- breeds with over 20 dogs of the breed represented
- Doberman pinscher, 59 of the 369 dogs (5:1 male to sex:F ratio)
- peak incidence at 7 years of age (most were 5-10 years of age)
- boxer, 53 dogs (3:1 male to sex:F ratio)
- peak incidences at 6 and 9 years of age
- great Dane, 38 (6:1 male to sex:F ratio)
- cocker spaniel, 30 (3:1 male to sex:F ratio)
- German shepherd dog, 24 (6:1 male to sex:F ratio)
- St Bernard, 20 (5:1 male to sex:F ratio)
- Labrador retriever, 20 (3:1 male to sex:F ratio)
- medium and large breeds dogs over 15 kg, 95% of the dogs
- median weight of all dogs: 37 kg
- median age at presentation: 6.67 years of age
- male, 73% (2.7:1 male to sex:F ratio)"

When boxers have cardiomyopathy, their first sign is OFTEN syncope and collapse (sometimes death), and this is before anyone knew they had a problem.
"syncope/collapse, 26%
- 70% of the boxers presented with this sign"

The incidence of VPCs in boxers with cardiomyopathy (which again, no one knows they even have at the time they present) is quite high--higher than other breeds:

"ECG, available in 94.6% of the cases
- arrhythmia, 89% of the 369 dogs
- atrial fibrillation, 49% (most common in giant and large breed dogs)
- ventricular premature complexes, 31% (most common in boxers and Dobes)
- supraventricular premature complexes, 9%

Unless you are running ECGs on all boxers prior to induction of anesthesia or administration of acepromazine, you won't be likely to pick it up:

"Laboratory findings: mean and medians for all dogs were within normal limits"

So you take a breed with a known pre-disposition to occult cardiomyopathy leading to syncopy and collapse and give a drug known to cause bradycardia and hypotension, and you could kill the dog. From Plumb's:

"Acepromazine's effect on blood pressure (hypotension) is well described and an important consideration in therapy. This effect is thought to be mediated by both central mechanisms and through the alpha-adrenergic actions of the drug. Cardiovascular collapse (secondary to bradycardia and hypotension) has been described in all major species. Dogs may be more sensitive to these effects than other animals."


Ace has no reversal agent.

Granted, in a boxer without cardiomyopathy, the risk is no different than any other dog. The problem with boxers is that we often don't know they have cardiomyopathy until they collapse. Since there are alternatives for pre-medication, why take the gamble?

 

[Whyevernot55]

Man, I've been in vet med too long. I was just thinking about a horse who had a bad reaction to (I believe) valium. He just went bonkers on us...ran all over the farm, jumped through the front of a golf cart, broke a fence...It was just crazy. Ended up with minimal bruising and a handful of superficial scratches only.

Oh man. I had a VSD kitten (you could literally hear his heart murmur from across the room) who we neutered. The Dr tried to use mostly valium because of his hear defect, but OF COURSE he was one who had a bad reaction - he turned into a ball of claws and teeth and screaming murder. Normally as sweet as pie, but lord was that scary!
My other male kitten (deaf, but otherwise normal) had a reaction to something - when he woke up from his neuter his whole face swelled up. Why is it always my cats? 🙄

 

[david594]

Let me just through a link out there for some educational reading for everyone:

http://vasg.org/index.htm

 

[dyachei]

Doesn't acepromazine also cause paradoxical aggression in some dogs?

I know we don't use it here in Boxers simply because even if it is anecdotal, they'd rather not take the chance it was based on something.

 

[eventualeventer]

Man, I've been in vet med too long. I was just thinking about a horse who had a bad reaction to (I believe) valium. He just went bonkers on us...ran all over the farm, jumped through the front of a golf cart, broke a fence...It was just crazy. Ended up with minimal bruising and a handful of superficial scratches only.

Was this diazepam given by itself? What was it given for? I'm curious because I have never seen diazepam given for sedation in adult horses except along with ketamine as part of anesthetic induction protocol after premedication with xylazine or detomidine. I've seen it given alone for seizures (mostly in young horses). My understanding is that it is not very good for providing sedation in horses.

I was thinking more of penile paralysis, but that's because it was the end of a VERY long week and my brain is functioning at barely gutter level.

As an aside, we typically use DexDomitor/Ket/Torb or some combination thereof IM for pre-anesthetic injection, induce with Ket/Val IV if necessary - most of the time they're zonked enough to tube and put on inhalant from the pre-an. We've seen bad reactions to some stuff though - yesterday an 8mo English Setter in for a neuter had a seizure after the pre-an and spent the rest of the day being babysat because the ketamine made him hyperreactive.

Have there been any cases reported of penile paralysis in dogs?

In horses, I've been told to never give ketamine without making sure that the horse is pretty significantly sedated by premeds. Never heard of a bad reaction lasting that long, though, interesting.

 

[sofficat]

It's not that the drug is different in boxers, it's that boxers are different. They don't tend to show their heart disease until they collapse. So you are correct that Acepromazine does not "do anything different to boxers." BUT boxers are more likely that other breeds to have an underlying cardiomyopathy making them more sensitive to the effects of acepromazine.

Boxers and Dobermans have a MUCH higher incidence of occult cardiomyopathy than other breeds:
http://www3.interscience.wiley.com/journal/121527251/abstract?CRETRY=1&SRETRY=0

"Retrospective report on the signs of dilated cardiomyopathy in 369 dogs in the UK:
History & Signalment of the dogs seen at a referral cardiology clinic
- purebred dog, 365 of the 369 dogs
- breeds with over 20 dogs of the breed represented
- Doberman pinscher, 59 of the 369 dogs (5:1 male to sex:F ratio)
- peak incidence at 7 years of age (most were 5-10 years of age)
- boxer, 53 dogs (3:1 male to sex:F ratio)
- peak incidences at 6 and 9 years of age
- great Dane, 38 (6:1 male to sex:F ratio)
- cocker spaniel, 30 (3:1 male to sex:F ratio)
- German shepherd dog, 24 (6:1 male to sex:F ratio)
- St Bernard, 20 (5:1 male to sex:F ratio)
- Labrador retriever, 20 (3:1 male to sex:F ratio)
- medium and large breeds dogs over 15 kg, 95% of the dogs
- median weight of all dogs: 37 kg
- median age at presentation: 6.67 years of age
- male, 73% (2.7:1 male to sex:F ratio)"

When boxers have cardiomyopathy, their first sign is OFTEN syncope and collapse (sometimes death), and this is before anyone knew they had a problem.
"syncope/collapse, 26%
- 70% of the boxers presented with this sign"

The incidence of VPCs in boxers with cardiomyopathy (which again, no one knows they even have at the time they present) is quite high--higher than other breeds:

"ECG, available in 94.6% of the cases
- arrhythmia, 89% of the 369 dogs
- atrial fibrillation, 49% (most common in giant and large breed dogs)
- ventricular premature complexes, 31% (most common in boxers and Dobes)
- supraventricular premature complexes, 9%

Unless you are running ECGs on all boxers prior to induction of anesthesia or administration of acepromazine, you won't be likely to pick it up:

"Laboratory findings: mean and medians for all dogs were within normal limits"

So you take a breed with a known pre-disposition to occult cardiomyopathy leading to syncopy and collapse and give a drug known to cause bradycardia and hypotension, and you could kill the dog. From Plumb's:

"Acepromazine's effect on blood pressure (hypotension) is well described and an important consideration in therapy. This effect is thought to be mediated by both central mechanisms and through the alpha-adrenergic actions of the drug. Cardiovascular collapse (secondary to bradycardia and hypotension) has been described in all major species. Dogs may be more sensitive to these effects than other animals."


Ace has no reversal agent.

Granted, in a boxer without cardiomyopathy, the risk is no different than any other dog. The problem with boxers is that we often don't know they have cardiomyopathy until they collapse. Since there are alternatives for pre-medication, why take the gamble?

That is a good point, but my experience in clinics is "Don't ever give ace to a boxer" not "don't ever give ace to a boxer or dobe." You are right in that ANY dog with DCM it would be bad to give anything that causes hypotension.

 

[critterfixer]

Let me just through a link out there for some educational reading for everyone:

http://vasg.org/index.htm

Nice site! I wish we'd had that as a reference in 2nd year, as it is quite well organized.

 

[critterfixer]

Doesn't acepromazine also cause paradoxical aggression in some dogs?

I know we don't use it here in Boxers simply because even if it is anecdotal, they'd rather not take the chance it was based on something.

Yes, I seem to remember that it causes some level of disinhibition and therefore makes aggressive dogs more likely to act out.

 

[Whyevernot55]

Have there been any cases reported of penile paralysis in dogs?

In horses, I've been told to never give ketamine without making sure that the horse is pretty significantly sedated by premeds. Never heard of a bad reaction lasting that long, though, interesting.

RE penises and dogs on Ace: Not that I know of, but I suppose it's possible - anyone else heard of it? I've only seen it in horses.

 

[Tobysgirl81]

Was this diazepam given by itself? What was it given for? I'm curious because I have never seen diazepam given for sedation in adult horses except along with ketamine as part of anesthetic induction protocol after premedication with xylazine or detomidine. I've seen it given alone for seizures (mostly in young horses). My understanding is that it is not very good for providing sedation in horses.

It was NOT given by itself, but its been a few years so I don't remember what it was mixed with. The patient was being sedated for a dental procedure - I THINK floating. I'm pretty sure he had a far molar that was very sharp and needed to be filed, but he was particularly sensitive to it.

Honestly, I got there just in time to see the horse yank back from his owner and take off running. I didn't know what had happened until a few minutes later when someone explained it as we were trying to catch him. I do remember the owner, who was a vet student at the time, told me later they had used valium as part of the drug protocol and they were pretty sure that's what he reacted to.

 

[alliecat44]

I heard the whole "never give acepromazine to Boxers or thiopental to sighthounds!" thing for years.

As far as Boxers go--I think critterfixer nailed it--Boxers are predisposed to a somewhat-unique type of cardiomyopathy, the first symptom of which is often collapse/sudden death. (It looks like that study lumped in a bunch of dogs suffering from the more general definition of "occult" CM--without reading the whole article, I would imagine that both dilatative cardiomyopathy and "Boxer cardiomyopathy," which has different findings on histopathology, were represented.)

But--I would argue that any of those signs (VPC's, a-fib, other arrythmias) would be picked up on physical exam BEFORE you designed the sedation protocol. In other words, if you ausculted the dog properly and palpated pulses assessing for strength and synchrony--what is the negative predictive value of that test (your physical exam)? If the dog seems to be completely healthy with a thorough physical exam, I personally wouldn't have a problem administering ace to a Boxer if I felt it was needed. (However, as in all things, I could be wrong...and hopefully won't kill something!)

re: sighthounds and thio--the only breed-sensitivity known is that of Greyhounds, and it is NOT to do with their body fat percentage--it IS to do with genetics causing a decreased metabolism of the sulfur group (? I think that's the component they have trouble with) in the brain. Maybe for a whole 'nother thread, I dunno. 🙂

re: penile prolapse in stallions--horses have a different composition of alpha and beta receptors in their genitalia than dogs/cats do--which is why we see it in the equine and not in dogs/cats. (acepromazine is an alpha-1 antagonist)