Acepromazine for Dogs: Caution Advised

Acepromazine, commonly known as ace, is a familiar medication to many dog owners. It can be a useful drug, and it can be a dangerous drug.

Acepromazine is a sedative or tranquilizer. As such, it is used to “mellow” out your dog. It can also help some dogs with motion sickness. So, if you are planning a six-hour car trip with your hyper, car-sick dog, acepromazine may be the drug for you. Most dogs show the effects for hours, so you could have a peaceful trip.

Some dogs show reverse effects, however. Instead of mellow and tranquil, they become hyper and potentially even aggressive. If you want to use ace on a trip, be sure to do a “test run” at home first.

It is important to realize that acepromazine is not an anti-anxiety medication. While its sedating effects may mean that your dog lies quietly during a storm due to physical effects, it does nothing for the mental state of your dog to ease his fears. Your dog may be quiet and still, but he is also scared. There are now much better options for things like thunderstorm and fireworks fears such as trazadone.

Acepromazine is also not a pain medication. Yes, it may appear to be as your dog lies quietly after receiving ace, but the drug is not reducing his pain, just his activity.

How to Give a Dog Ace

Acepromazine is handy in that it can be given as an injection in the muscle, under the skin or in a vein. It can also be given orally as a pill.

Timing of effectiveness depends on how it is given. An oral pill may take up to 45 minutes to show effects, while an IV injection happens quickly.

Acepromazine is also used as part of some anesthetic protocols. It is usually given as a preanesthetic. There is no reversal agent for acepromazine. Dogs who are sensitive to this drug may show prolonged sedation, meaning a longer hospital stay under observation.

Ace and the MDR1 Mutation

It is important to note that acepromazine is one of the drugs affected by the MDR1 mutation. Dogs in the NDR1 mutation group include many herding breeds, as well as some sighthounds. If ace is used in these breeds—and, honestly, it should generally be avoided—a lower dose is important.

If your dog is on the MDR1 mutation known list, or is a mix of a breed on the list, it is worthwhile to have your dog DNA tested. The metabolism of many drugs is affected by this defect.

My own primary breed, Belgian Tervuren, tend to react strongly to acepromazine, as do the other Belgian breeds. This is not due to the MDR1 mutation, so there must be other factors. Some experts propose the amount of lean muscle versus fat is a factor (this would fit with many sighthounds as well). Ace is not recommended for use in this breed.

Acepromazine also interacts with many medications. That list includes metronidazole and ondansetron. Some flea and tick treatments have prolonged effects. Ace can also lower blood pressure so it can be dangerous in older dogs or dogs with heart conditions.

Acepromazine Dosage for Dogs

If, after reading this, you are still considering giving ace to your dog, for ORAL administration, my dose suggestion is 0.25 to 1 mg per pound of body weight. However, since this drug is not available without a prescription, you should be working with a veterinarian. Your vet will give you the exact dosage amount for your individual dog, which might be lower or higher than the one above.

The bottom line is that there are almost always better options with drugs that can accomplish the sedation of acepromazine with lower risks and side effects. Talk with your veterinarian.