Rectal Diazepam for Dogs: Emergency Seizure Use
By Dr. Zubair Khalid, DVM, MS, PhD ·
Rectal diazepam for dogs is a prescription seizure rescue medicine that your veterinarian may send home with you if your dog has a history of cluster seizures. It is given into the rectum when a seizure will not stop or when seizures are coming one after another, and it buys time while you get your dog to veterinary care. It is not a substitute for emergency treatment, and it is not something you should start on your own.
This article is educational and is not a substitute for veterinary diagnosis or treatment.
Quick Answer
- Rectal diazepam is used as an at-home emergency treatment for dogs with a history of cluster seizures, and owners can give it up to 3 times in a 24-hour period [1].
- It is given into the rectum using the injectable diazepam solution, not a pill or a human suppository [1].
- Your veterinarian calculates the dose from your dog's weight and sets the exact amount for your pet. Never guess or reuse a dose from another dog.
- Rectal diazepam does not replace the emergency room. Give it as directed, then call your vet or an emergency hospital right away.
- Intranasal midazolam is another option some veterinarians use, and clinical trials show it controls emergency seizures more reliably than rectal diazepam [2][3].
What Rectal Diazepam Is and What Veterinarians Use It For
Diazepam is a benzodiazepine, a class of drug that calms abnormal electrical activity in the brain. Benzodiazepines are the recommended first-line treatment for canine seizure emergencies [2]. Veterinarians use diazepam in the hospital by intravenous injection when a dog is actively seizing, and they also prescribe it for owners to give at home by the rectal route.
The rectal route matters because a seizing dog cannot safely swallow a pill. When there is no IV access, giving diazepam into the rectum is a convenient way to get the drug into the body during status epilepticus, which is a seizure that does not stop on its own [1]. Rectal administration of the injectable diazepam solution is routinely recommended as an at-home emergency treatment for some dogs with a history of cluster seizures [1].
Cluster seizures are multiple seizures within a short window. They are a medical emergency because the brain does not fully recover between events. If your dog has this pattern, your veterinarian may send you home with diazepam and a written seizure action plan. That plan tells you exactly when to give the medicine, how much to give, and where to go afterward.
Some veterinarians now prefer intranasal midazolam, a benzodiazepine given as a spray into the nose. A multicenter randomized trial found that intranasal midazolam is effective at controlling seizures in dogs with status epilepticus, with a speed of onset that makes it a suitable first-line option when IV access is not quickly available [3]. Another study comparing routes found that intranasal midazolam controls emergency seizures more reliably than rectal diazepam [2]. Rectal diazepam is still widely prescribed and still works for many dogs, so follow the plan your own veterinarian gives you.
If your dog is seizing right now and you are not sure what to do, start with Dog Seizures: Emergency Steps and When to Go to the Vet.
How Diazepam Works
Diazepam boosts the effect of GABA, a chemical messenger that quiets overactive nerve signals in the brain. The result is less seizure activity and often some sedation. The drug moves quickly once it is absorbed, which is why it is used for emergencies and not for daily seizure prevention.
Rectal absorption is not as predictable as an intravenous injection. That is one reason intranasal midazolam has gained ground in emergency seizure care [2][3]. Even so, rectal diazepam remains a practical bridge when you are alone with a seizing dog at home and need to act before you can reach a hospital [1].
Diazepam is a short-acting rescue drug. It is not meant to control seizures around the clock. Dogs that need ongoing seizure control are usually placed on a maintenance anticonvulsant, and in the hospital a veterinarian may start an intravenous maintenance drug such as phenobarbital after repeated boluses of diazepam [1]. If your dog needs rectal diazepam often, that is a signal that the maintenance plan needs review.
How to Give Diazepam Rectally to a Dog
This is the part owners worry about most. The good news is that it is faster and simpler than it sounds once you have practiced it.
Before a seizure happens
Ask your veterinarian to show you the technique in person, and ask them to write the dose in milliliters on the label. Keep the diazepam, a syringe, water-based lubricant, and gloves together in one spot. Diazepam is a controlled medication, so store it securely and check the expiration date. If the solution looks cloudy or has particles in it, call your veterinarian before using it.
During a seizure
- Stay calm and keep your hands away from your dog's mouth. Dogs can bite without meaning to during a seizure.
- Draw up the dose your veterinarian prescribed into the syringe.
- Coat the tip of the syringe with a water-based lubricant.
- Lift your dog's tail and insert the syringe into the rectum, aiming gently forward and slightly to the side.
- Deposit the solution and hold the tail down against the rectum for a few seconds so the medicine does not leak out.
- Note the time you gave the dose and how long the seizure lasted.
- Call your veterinarian or the nearest emergency hospital.
Do not give a second dose unless your written plan tells you to. The general limit is up to 3 doses in a 24-hour period, but your veterinarian sets the specifics for your dog [1].
If you miss a dose
There is no scheduled dosing with rectal diazepam, so a missed dose works differently than with a daily pill. If your dog has a seizure and you cannot give the medicine, or you are unsure whether the last dose was fully absorbed, call your veterinarian or an emergency hospital for guidance. Do not stack extra doses to make up for one that did not go in.
If your dog has already had a seizure and you are watching for the next one, Dog Had Seizure What To Do walks through the next steps.
Side Effects of Rectal Diazepam in Dogs
Most side effects are the expected result of a sedating drug. Some are serious and need immediate attention.
| Side effect | How common or serious | What to do |
|---|---|---|
| Sleepiness, drowsiness, sedation | Common and expected with benzodiazepines [3] | Let your dog rest in a quiet, safe space. Mention it at your next visit. |
| Wobbliness or unsteady walking | Common after a dose | Keep your dog on the floor or a low surface to prevent falls. |
| Increased appetite or mild stomach upset | Possible | Offer small amounts of water. Call your vet if it continues. |
| Rectal irritation or leakage of the solution | Possible with rectal dosing | Wipe the area gently. Tell your vet if you see blood or ongoing discomfort. |
| Paradoxical excitement or agitation | Uncommon | Call your veterinarian the same day. |
| Trouble breathing, collapse, or a seizure that will not stop | Serious | Go to an emergency hospital now. |
Sedation and drowsiness are the side effects most often reported with benzodiazepine use in dogs, and serious adverse events are uncommon [3]. Still, a dog that is deeply sedated, struggling to breathe, or not waking up needs to be seen right away.
Who Should Not Take It and Drug Interactions
Diazepam is not right for every dog. Your veterinarian will weigh your dog's full health picture before prescribing it.
Dogs with certain liver conditions, severe breathing problems, or a known sensitivity to benzodiazepines may not be good candidates. Tell your veterinarian about every medication, supplement, and over-the-counter product your dog takes, including flea and tick products. Drug interactions can change how diazepam works or increase sedation.
Pregnancy and nursing status matter too. If your dog is pregnant or nursing, your veterinarian needs to know before any dose is given.
Never share diazepam between pets. A dose that is right for one dog can be dangerous for another. Never use leftover human diazepam or a human suppository in your dog unless your veterinarian specifically instructs it.
Overdose and When to Call for Help
An overdose of diazepam can cause heavy sedation, loss of coordination, slow or shallow breathing, and in severe cases, collapse. If you think your dog received too much, call for help immediately.
Call your veterinarian or an emergency hospital right away. You can also contact the ASPCA Animal Poison Control Center at (888) 426-4435 or the Pet Poison Helpline at (855) 764-7661. Have the bottle, the strength, the amount given, and your dog's weight ready.
Do not wait for symptoms to appear before calling. Early guidance makes a real difference.
Limitations and When to Contact a Veterinarian
Rectal diazepam is a rescue tool, not a cure. It does not fix the underlying reason your dog is seizing, and it does not replace hospital care. Every dog is different, and your veterinarian is the only person who can set the right plan for your pet.
Contact your veterinarian the same day if your dog needed a rescue dose, if the seizure lasted longer than usual, if your dog seems more sedated than expected, or if you had trouble giving the medicine.
Go to an emergency hospital now if a seizure lasts more than a few minutes, if seizures keep coming without your dog fully waking up between them, if your dog has trouble breathing, or if your dog does not wake up after a rescue dose. Cluster seizures and status epilepticus are emergencies that need injectable treatment and monitoring [1][4].
Ask for a routine visit if you want to review your seizure action plan, refill an expired diazepam prescription, or discuss whether intranasal midazolam might suit your dog better [3]. If you are in the middle of an event and need step-by-step help, Dog Having Seizure What To Do is a good place to start.
Frequently Asked Questions
Can I use a human diazepam suppository in my dog?
No, not unless your veterinarian specifically tells you to. The at-home rectal method uses the injectable diazepam solution, which is what veterinarians routinely recommend for this purpose [1]. Human suppositories come in strengths and forms that are not designed for dogs, and the dose would be wrong. Always use the exact product and amount your veterinarian prescribes.
How fast does rectal diazepam work in a dog?
It usually starts working within minutes, but it is not instant. Rectal absorption is less predictable than an intravenous injection, and research shows intranasal midazolam controls seizures more reliably than rectal diazepam [2]. If your dog is still seizing several minutes after the dose, treat it as an emergency and get to a hospital.
Can I give rectal diazepam every time my dog has a seizure?
Only if your veterinarian's written plan says so. The general guidance allows up to 3 doses in a 24-hour period for at-home use [1]. If your dog needs rescue medicine often, that usually means the daily seizure control plan is not working well enough and needs to be changed. Call your veterinarian to review it.
Is rectal diazepam the same as the diazepam my dog takes by mouth?
No. Rectal diazepam is a rescue treatment for seizure emergencies, while daily seizure control is handled with maintenance anticonvulsant medication. In the hospital, a veterinarian may add an intravenous maintenance drug such as phenobarbital after repeated diazepam doses [1]. Keep the two roles separate and never swap one for the other without veterinary direction.
What should I write down during a seizure at home?
Record the time the seizure started, how long it lasted, what the seizure looked like, and the time you gave the rescue dose. Note whether your dog was fully normal between seizures. This log helps your veterinarian judge how well treatment is working and whether the plan needs to change. Bring it to every appointment.
Related Articles
- Dog Seizures: Emergency Steps and When to Go to the Vet
- Dog Has Seizure What To Do
- Dog Having Seizure What To Do
- Dog Had Seizure What To Do
- What To Do When Dog Gets Seizures
- What to Do If Your Dog Has a Seizure After Starting Medication
- Diazepam for Dogs: Side Effects and Seizure Use
- Diazepam for Dogs: Dosage and Safety
- How Long Does Diazepam Last in Dogs? Onset and Duration
References
- Anticonvulsants for Emergency Treatment of Seizures in Dogs and Cats - Pharmacology. Merck Veterinary Manual.
- Quantitative electroencephalographic comparison of intranasal midazolam, intranasal saline, and intrarectal diazepam in healthy dogs: A two-session, fixed-order pilot study. Veterinary journal (London, England : 1997), 2026.
- Intranasal midazolam as an alternative to rectal diazepam for management of canine status epilepticus. Veterinary evidence, 2024.
- Duration of constant rate infusion with diazepam or propofol for canine cluster seizures and status epilepticus. Frontiers in veterinary science, 2023.