Benadryl Killed My Dog (How & What’s Next?)

For pet owners, the thought of losing our pets is a nightmare. We’re so attached to them we can’t even imagine life without them. So when something like this happens, it’s devastating.

When I searched ” Benadryl killed my dog” in Google, I got very few stories about Benadryl killing dogs.

In fact, I haven’t encountered such an incident in my 7 years of practice as a veterinarian either. So is it really possible for Benadryl to kill your dog?

We’re going to explore this question today. First let’s start with the most basic question:

What Is Benadryl?

Benadryl is a popular antihistamine that has been used for decades to treat allergies. It is one of the most common medications taken by people with allergies, and it’s available over the counter in many countries.

The active ingredient in Benadryl is diphenhydramine, which works by blocking histamine receptors in your body. Histamines are chemicals released by your immune system when you have an allergic reaction. These histamines cause symptoms like itching, sneezing, watery eyes, and congestion. Diphenhydramine blocks these receptors, which prevents them from being activated by histamines and stops you from having an allergic reaction.

Can Benadryl Kill Your Dog?

Technically yes. Benadryl can kill your dog. (source)

Diphenhydramine, the active ingredient of Benadryl, can cause severe neurological and cardiovascular effects at very high doses. The results include hyper-excitability, rapid heartbeat, seizures, convulsions, myocardial depression or respiratory failure.

However, it’s doubtful that level of overdose unless your dog had access to an entire bottle of Benadryl.

How Much Benadryl Is Safe For My Dog for Itching?

Giving your dog Benadryl for itching is a great way to help them feel more comfortable. According to Merck Veterinary Manual, you can administer 2-4 milligrams of Benadryl per kilogram of body weight, two to three times a day.

The best way to figure out how much Benadryl is right for your dog is by trial and error. Start with the minimum amount recommended by Merck (2 milligrams per kilogram) and go from there until you find the right amount that helps your pup feel better but doesn’t make them sick or drowsy.

It’s important to remember that too much can cause serious side effects and even death. If you’ve given your dog more than the recommended dose and are concerned about their health, contact your vet immediately.

What Happens If I Give My Dog Too Much Benadryl?

If you give your dog too much Benadryl, it can cause serious side effects including sedation, incoordination, vomiting and diarrhea. In severe cases, it can cause seizures or difficulty breathing. If your dog has any underlying health conditions, giving them too much Benadryl can put them at risk for complications.

Therefore, it’s important to only give your dog the recommended dosage of Benadryl and to contact your veterinarian if you have any concerns.

What Should You Do if You Overdose Your Dog With Benadryl?

If you’ve overdosed your dog with Benadryl, it’s important to act quickly. These are the steps you can take:

1. Contact your vet or animal hospital immediately and let them know what happened. Your vet will give you advice about what to do next.

2. If your dog is unconscious and not breathing, try to wake him up by calling his name and shaking him gently by the shoulders. If that doesn’t work, try rubbing his sternum with both hands at once, or tickling the inside of his ear. If this doesn’t work either, proceed to step 3 below!

3. If your dog is still unconscious after trying these methods, move on to doing rescue breathing for him until he breathes again on his own (this could take several minutes).

Will Benadryl Make My Dog Sleepy?

Yes, Benadryl can make your dog sleepy. Benadryl is a medication used to treat allergies in humans and dogs alike. It’s made from diphenhydramine, which is an antihistamine that blocks the effects of histamines in your body.

The side effects that are most likely to occur are drowsiness, dry mouth, and constipation. You should know these side effects before giving your dog any sort of medication, including Benadryl. If your dog has trouble moving around or seems exhausted after taking the drug, it may be a sign that the dosage needs to be decreased or adjusted.

Will a 25Mg Benadryl Hurt a Dog?

A normal dose of Benadryl for a dog is 2-4 milligrams per kilogram of body weight. This means that a 25 milligram dose would be appropriate for a 10 pound dog, and a 50 milligram dose would be appropriate for a 20 pound dog. If your dog is larger than that, simply calculate the dosage with the same formula: 2-4 mg per kg.

For example: A 40 pound dog would need 40 mg of Benadryl per kilogram of body weight (40 x 2.2).

How Long Does It Take for a Dog to Overdose on Benadryl

It takes approximately 10 to 60 minutes for a dog to overdose on Benadryl, depending on the size and weight of the dog. The larger the dog, the longer it will take for them to overdose. In general, if you see your dog acting strange after taking Benadryl, contact your dog vet immediately so they can help your pet recover from any symptoms that they may be experiencing.

How Long Does It Take Benadryl To Wear Off on Dogs?

The effects of Benadryl will wear off in about 24 hours, depending on the size of your dog. It’s important to remember that if your dog is taking any other medications, their reaction time will be different, and you should always consult with a vet before giving them anything new.

If your dog is having trouble sleeping, it’s probably because he’s not getting enough rest during the day. Your vet can help you make sure your dog gets enough sleep without using Benadryl or any other medication.

How Much Benadryl Is Fatal For Dogs?

The lethal dose (LD50) for diphenhydramine in dogs ranges between 24 to 30 mg/kg BW by IV administration. (source) This is equivalent to 300 mg of Benadryl for a 20 pound dog and 800 mg for a 50 pound dog.

If you suspect your dog has ingested too much of this medication, it’s important to call your vet and get them checked out immediately. They’ll likely need to be hospitalized for observation and treatment.

Are There Any Dogs Who Shouldn’t Take Benadryl?

There are a few dogs who shouldn’t take Benadryl, but if you know your dog well enough, you can probably determine which ones they are.

First, we do not recommend Benadryl for dogs who are taking gabapentin, lisinopril, or metoprolol.

If your dog has any sort of liver disease or kidney disease—or if they’re taking other medications that could increase their risk of side effects from Benadryl—they should definitely not take the medication unless directed by their veterinarian.

Benadryl isn’t recommended for pregnant or nursing dogs because it can affect their babies’ health if passed through breast milk. Also, if your dog has been on long-term steroids or antihistamines (as opposed to short-term use), then it’s best to avoid Benadryl as well.

If none of these apply to your pet, then there’s no reason he or she shouldn’t take Benadryl under normal circumstances.

What Should You Do if Your Dog Skips a Benadryl Dosage?

If your dog skips a Benadryl dosage, it’s important to give the next one at the usual time. If you’re not sure when that is, check with your veterinarian.

If you’ve given an extra dose of Benadryl to compensate for the skipped one, don’t repeat that dose. And don’t double up on future doses if you’re unsure of how much Benadryl your pet has already had.

Are There Any Alternatives To Benadryl For Dogs?

There are several alternatives to Benadryl for dogs, but they’re all similar in their method of action. When looking for an alternative to Benadryl, consider whether you want your dog to be sedated or simply have an allergic reaction alleviated.

If you don’t need your dog to be sedated, but just want them to feel less bothered by the symptoms of their allergies, then Zyrtec and Claritin are both good options. Zyrtec is a prescription medication that is often used as a substitute for Benadryl in humans, and Claritin is an over-the-counter option that can be given to dogs at home without a prescription. Both medications work by blocking histamine receptors in the body, which prevents the allergic reaction from happening.

Always talk to your vet before administering any type of medication.

Should You Consider Suing Your Vet for Overdosing Your Dog?

Yes, consider suing your vet for overdosing your dog.

It’s not a simple answer, though. You need to be sure that the overdose was caused by negligence on the part of your vet, and not just a mistake.

When your dog overdosed on medication, it’s important to know what happened and how to prevent it from happening again in the future. If you feel your vet was negligent in their treatment of your dog, you may sue them. But before you do, it’s important to understand how legal actions like this work.

Many people think that it’s easy to sue someone for malpractice or negligence—and while that’s true sometimes, there are many factors that go into deciding whether you have grounds for a successful suit, including:

  • The severity of the injury/damage caused by the malpractice/negligence
  • The type of malpractice/negligence involved (e.g., neglect vs. medical error)
  • Whether there was an expectation that the injured party would be harmed by the malpractice/negligence (e.g., someone who has been driving for years would never expect to be injured in an accident because they know accidents can happen)

Support Groups and Pet Bereavement Services

You’re not alone.

We know that losing a pet is one of the most painful experiences you can have. And we also know that the pain isn’t always physical. Sometimes, it’s emotional—that feeling of having lost part of yourself.

It’s for this reason that we’ve created a space where you can feel comfortable coming together with other people who have gone through similar situations and sharing your stories, your feelings, and your experiences. We hope that you’ll find comfort in knowing that there are others out there who understand what it feels like to lose a pet and want to help support you through this difficult time in your life.

When a beloved pet dies, some people like to get together with others who have experienced the same loss. Support groups provide a safe space to share stories, laughter, and tears with those who understand what you’re going through.

If you want to attend a support group for pet bereavement, here are some things to look for in a group:

1. The group should be open to all types of pets, not just dogs or cats.

2. The group should be open to many owners (e.g., people who have lost their pets and people who have recently adopted an animal).

3. The facilitators should be trained in grief counseling or other related fields (e.g., social work).

4. The facilitators should have experience working with groups dealing with grief over pet death (e.g., they may be involved with other groups that assist people dealing with grief over pet loss).

We recommend RainbowsBridge and Lap of Love, both of which offer great support in their online forums and chat rooms.

RainbowsBridge offers an online forum with caring volunteers ready to help at any time between 8 and 12 pm EST, while Lap of Love offers pet loss support groups and organizes weekly sessions on Zoom throughout the week led by their Pet Loss Support Team. Here is where you can find yourself in a safe and compassionate space to listen and share each other’s stories and help one another through loss.

Benadryl Killed My Dog- A Reddit Story

It’s every pet owner’s nightmare. You give your dog a medication that you think is safe, only to have them suffer an adverse reaction or even die from it. This is what happened to one Reddit user, whose dog died after being given Benadryl.

The user, u/cant_sleep_love, took to the popular subreddit r/pets to share their story in a post titled “Benadryl killed my dog.” In it, they recount how their vet had recommended giving their dog Benadryl for anxiety and stress relief. They gave their dog the recommended dosage of one milligram per pound of body weight.

Unfortunately, within hours of taking the medication, their dog began vomiting and having diarrhea. They took him to the emergency vet where he was treated for dehydration and then released. The next day, however, their dog’s condition worsened, and he began having seizures.

He was rushed back to the emergency vet where he later died. The Redditor says that they know now that Benadryl can be deadly for dogs and are warning others about the potential risks. They urge anyone who is considering giving their dog Benadryl or any other medication to first speak with a veterinarian about possible side effects and dangers.

Find Out Whether Other Things That Can Kill Your Dog


It’s important to remember that not all drugs are created equal.

Just because a medication worked for one person or animal, doesn’t mean it will work the same for another. Every body is different and reacts differently to medications. That being said, we want to remind our readers that Benadryl is a powerful drug.

It should only be used as directed by a veterinarian, and even then, it can be dangerous. We urge everyone to be careful when using this drug and always follow their vet’s directions. Again, we’re so sorry for your loss, and our thoughts are with you during this difficult time.

Share This Article To Help Others: