Acepromazine is commonly used as a tranquilizer and sedative for a number of animals, including dogs, cats, and horses. The drug is used to treat anxiety, as well as to combat motion sickness and nausea. Because it can help with anxiety, acepromazine is sometimes given to pets before they are anaesthetised for surgery too. Acepromazine is derived from a chemical called phenothiazine, which itself has been used to treat nausea in the past. It can be obtained from a licensed vet via prescription.

acepromazine - medicine for dogs

Despite acepromazine’s wide usage, no one knows the exact mechanism by which it works. It is thought to inhibit dopamine uptake in animals’ brains – most likely by blocking dopamine receptors. Dopamine is a chemical signal involved in a whole host of bodily functions, including physical movement, memory, and even behavior. Since it can also be detected by receptors in the stomach, it can influence an animal’s digestive tract too.

Dopamine can be hugely beneficial as a feel-good chemical, but levels which are too high sometimes trigger adverse effects. These effects include anxiety and nausea, which is why drugs that stop dopamine from interacting with the body’s receptors are effective at treating these symptoms.


Acepromazine is used to target anxiety and nausea in specific, foreseen scenarios, such as a long car journey, upcoming fireworks display, or surgery. The drug will impair your pet’s motor functions, so is not suitable for use as a long-term solution to underlying anxiety or nausea issues. Below we outline some circumstances under which acepromazine can be effectively used:

  • Long Distance Travel and Motion Sickness

If you are planning a long journey with a dog who is overly energetic, prone to motion sickness, or anxious about travel, acepromazine could help. Medicating an excitable pet for long car journeys might seem extreme, but it’s worth considering if their bounding about or constant barking could distract or otherwise impede the driver.

  • Pre-Surgery

Veterinary professionals might choose to treat a dog with acepromazine before an operation if the animal is particularly skittish or energetic. The sedative effect of the drug renders dogs easier to handle, reducing stress levels for vet and dog alike.

  • Post-Surgery – treating Nausea and aiding Recovery

Acepromazine can also be used after surgery. Some dogs become nauseous as they recover from anaesthetic, and acepromazine reduces vomiting, making your pet more comfortable whilst simultaneously reducing the risk of dehydration. Pets who are full of energy quickly after surgery could also benefit. Being sedated, they will not push their bodies too far, aiding recovery and ensuring that any incisions are not re-opened.

  • Aggression

If an aggressive dog needs to be handled, especially by a person they are not familiar with, acepromazine might be prescribed to sedate them. This practice is becoming less common, however, with Diazepam (Valium) and Alprazolam (Xanax) being offered as alternatives.

  • Stressful Situations

For dogs who are sensitive to loud noises such as fireworks or thunderstorms, acepromazine might be prescribed to reduce their anxiety during these kinds of events.

Related Post: Calming Supplements for Dogs

  • A Vet or Groomer Visit

If a dog becomes anxious or aggressive during trips to the vet, groomer, or other professional who needs to handle them, acepromazine can be used. When a dog is calm and sedated, the professional can work more safely and effectively, reducing stress for everyone involved.

Potential Side Effects

Acepromazine is FDA approved for use in dogs, but each animal’s sensitivity to the drug varies, and there are a number of possible side effects to be aware of:

Some Common Side Effects

  • Low blood pressure
  • Slowed heart rate
  • Decreased rate of breathing
  • Unsteadiness when walking
  • Pale gums
  • Increased noise sensitivity

Some Rarer Side Effects

  • Unconsciousness
  • Fatal interactions with anaesthetics
  • Greater frequency of seizures in dogs with epilepsy
  • Allergic reaction (swelling, difficulty breating)

A sedative like acepromazine will naturally slow down your dog’s bodily functions, but if you observe one or more of these side effects it’s best to consult with your vet.                           

Things you Should Know About Acerpromazine

When it comes to acepromazine, the most important thing to be aware of is that certain breeds of dog tend to be particularly sensitive to the drug. These breeds are:

  • Boxers
  • Bulldogs
  • Pugs
  • Collies
  • Austrian Shepherds
  • Greyhounds
  • Giant breeds such as St Bernards

This does not mean that these breeds can never be medicated with acepromazine, but extra caution and lower dosages should be used. Strangely, terriers are often much less sensitive to acepromazine, and will need a higher dose than their body size would suggest.

acepromazine for dogs

Owners should also bear in mind that the effects of acepromazine on aggressive behavior are not fully understood, and will vary between dogs. Some studies suggest that the drug can actually inhibit impulse control, making certain animals more rather than less likely to bite. If your dog has not taken acepromazine before, your vet will probably recommend trialling the drug with a low dosage, since each animal’s body will react differently. Keep a close eye on your pet when they have taken acepromazine for the first time.

Acepromazine is not the only option for treating anxiety in pets, either. For coping with day to day stress, you might consider adjusting your dog’s routine or environment to avoid stress triggers, or consulting a behavioralist for tips on how to help your canine companion to cope. A pheromone-based calming spray or diffuser could also be a great natural alternative to medication for low-level anxiety.

What you Should Tell Your Vet Before They Prescribe Acepromazine

The negative side effects associated with acepromazine are exacerbated by certain underlying health issues. You should let your vet know if:

  • Your Dog is Epileptic

Acepromazine can make epileptic animals more likely to have seizures, so is best avoided if at all possible.

  • Your Dog has Heart Disease

Acepromazine lowers blood pressure, which means that the heart must work harder to raise it to a healthy level. This puts extra strain on the heart, which is a bad idea for dogs suffering from a cardiac condition. Acepromazine can still be administered to dogs with heart disease in some cases, but dosages tend to be far lower. Your vet will be able to make a recommendation.

  • Your Dog is Pregnant or Lactating

You should always let your vet know if your dog is pregnant or lactating when medication is being prescribed, since it could end up reaching her pups.

You should also use acepromazine with extra caution if your dog is elderly, since their body will be less efficient at breaking down the drug. The effects of acepromazine are likely to last longer in older dogs, so smaller doses are generally administered. The drug should also be used with caution in particularly young dogs, since their organs may not yet be fully developed, and equipped to metabolize the drug.

How to Give Acepromazine to Your Dog

Dosage will very much depend upon your dog’s breed, but you can expect them to be prescribed between 0.25 and 1 milligrams (mg) of acepromazine per pound of body weight. A 40 pound dog would be given between 10 and 40mg, for instance.

The drug takes 45 minutes to hour to take effect, and will not be effective if your dog is already stressed. Because of this, you should give your dog their dose an hour to 90 minutes before the stressful event or journey begins. The effects will last for between six and eight hours – your vet will be able to advise you about dosage frequency if your pet needs to be sedated for any longer. Acepromazine is usually prescribed in tablet form, making it fairly straight-forward to administer.

What to Do if You Miss a Dose

If you miss a dose, administer it to your dog as soon as you remember, provided this happens on the same day. If you do not realise the dose was missed until the next day, skip the missed dose altogether and return to the prescribed schedule. Never give your dog a double dose.

What to Do in Cases of an Acepromazine Overdose

If your dog ingests more acepromazine than they were prescribed, you should seek emergency veterinary treatment as soon as possible. Signs that your dog has overdosed include extreme drowsiness, unconsciousness, slow heart rate, and unsteady movement.

Some Drug Interactions

Unfortunately, acepromazine tends to mix badly with other drugs. For this reason, you should always let your vet know if your pet is currently taking any other medications, supplements, or herbal remedies.

Acepromazine can interact with flea and worm medications if they contain Organophosphate insecticides, as well as antacids, opioid pain relievers, and antidiarrheal drugs. Whether the effects of other medications are intensified or cancelled out by acepromazine will depend upon their unique chemical composition. Your vet will be able to provide the best advice about potential drug interactions for your pet.


Olivia Williams
Olivia is our head of content for, mum of one and a true animal lover. With 12 different types of animal in her family, it's never a dull moment. When she isn't walking the dogs, feeding the cats or playing with her pet Parrot Charlie, you will find her product researching and keeping the site freshly updated with the latest products for your pets!


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