Benadryl for Dogs: Is It Safe?

If your dog experiences allergy symptoms like itching, you may have wondered “Is there a Benadryl for dogs?” 

It would be much easier to give your pet some of the Benadryl you already have than to take a trip to the vet and get a prescription, wouldn't it? Well, you're in luck. You can use Benadryl for dogs with allergic reactions, but there are a few safety considerations to make.

This article will give you all the information on safety, safe dosage for dogs, liquid form, and more. Let's look at everything you, as a pet owner, need to know before giving this antihistamine to your dog.  

Benadryl for Dogs with Allergy Symptoms

Benadryl is the brand name of the generic antihistamine drug diphenhydramine. Diphenhydramine is the active ingredient in Benadryl, but many formulations contain additional ingredients or flavoring agents that could be harmful to dogs.

Before administering Benadryl to your dog, here are a few things to know:

1. Children's Benadryl tablets are the best option to use for your dog's allergies.

2. Make sure to talk to your veterinarian to get the appropriate dose, especially if your dog is taking any other medications.

3. Avoid liquid Benadryl with sodium.

4. Avoid any sprays or alternative forms of this drug, especially ones that advertise added flavors.

5. Do not use any creams or antihistamine formulations that contain additional ingredients such as xylitol or alcohol.

What are Antihistamines?

An antihistamine like Benadryl relieves an allergic reaction by blocking the action of histamine.

Diphenhydramine is available as an over-the-counter medication in many different forms, one of the most common of which is the brand name Benadryl.

Benadryl tablets come in various dosages. Liquid Benadryl is another option, but you should not use liquid Benadryl for your dog if it contains sodium, as sodium can harm your pet.

When considering liquid dosage, it is important to calculate the correct amount based on your dog's weight to ensure safe administration. The same is true if you're going to give your dog Benadryl tablets.

We'll discuss dose by body weight later on in this article.

What are Histamines?

"Histamine" is a compound released by cells in response to injury or during allergic or inflammatory reactions. Histamine is part of the process that causes allergic symptoms like sneezing, runny nose, difficulty breathing, swelling, hives, and itching.

Histamines help your dog respond to potential threats like viruses or bacteria. The problem comes when your dog's body overreacts and produces too much histamine or produces histamines in response to things that aren't threats.

Excessive dog allergies occur when your pooch's immune system overreacts to harmless things in their environment, producing histamine to battle a threat that doesn't exist. In some cases, the response can be so extreme that the dog allergic reaction itself becomes a threat of its own. 

Is Benadryl Safe for Dogs?

In general, Benadryl is safe for most dogs when you use the recommended dosage. Determining the appropriate dosage of Benadryl for your dog is essential and should be done in consultation with a veterinarian.

The original Benadryl formula is or children's Benadryl tablets are generally considered to be the most safe, but other formulations of Benadryl may not be safe for dogs. Benadryl should be used with caution.

Benadryl should not be used in patients with asthma attacks or in any patient with a known hypersensitivity to Benadryl.

Can I Give My Dog Benadryl if They Have a Condtion?

There are complications associated with using Benadryl for dogs with a handful of conditions. Avoid giving this product to dogs with the following issues.

1. Seizures

While many seizures in dogs can be mysterious, it's believed that the histamine receptors mediate an anticonvulsant effect. In other words, histamines may play a part in stopping seizures from occurring.

If your dog is already prone to seizures, giving Benadryl to them could increase seizure activity even if you're giving them the right dosage.

A Benadryl overdose can cause seizures in dogs, as too much diphenhydramine HCL may interfere with the body's natural ability to control convulsions.

2. Glaucoma

Antihistamines like Benadryl can prevent fluid from leaving the eye, which leads to a rise pressure. There are different types of glaucoma, however, so discuss with your veterinarian to learn whether or not your dog should avoid Benadryl.

3. Prostatic Hypertrophy

Prostatic hypertrophy may impact a dog's urinary system, and Benadryl's anticholinergic effects can lead to reduced bladder control. These effects can exacerbate the existing symptoms of prostatic hypertrophy.

4. Pyloroduodenal Obstruction

Dogs with this condition should avoid Benadryl because of its potential to cause decreased gastric motility, which can lead to complications and more severe symptoms of pyloroduodenal obstruction.

5. Liver Disease

Dogs with liver disease should generally avoid Benadryl due to several important concerns related to how the drug is metabolized and its potential impact on liver function. These concerns include liver metabolism, the potential for hepatotoxicity, and the side effects of possible drug interractions.

Exercise caution when using Benadryl for dogs with: Hyperthyroidism, intestinal atony, urinary retention, cardiovascular disease, high blood pressure, hypertension, chronic obstructive pulmonary disease.

If your dog has one of these conditions or another health condition, it’s best to talk to your veterinarian prior to using Benadryl for your dog to ensure that the product will be safe and effective. Certain medications may interact poorly

What Does Benadryl Treat for Dogs?

In dogs, Benadryl is commonly used to treat mild itching from environmental and seasonal allergies. It is not the preferred option for an anaphylactic reaction

1. Environmental & Seasonal Allergies

Dogs can be allergic to many things in their environment such as mites, different foods, snake bites, bug bites, and more. Dogs are curious by nature, so they're sure to investigate new things in their environments and many of those things pose the risk of allergic reactions.

In the case of seasonal allergies, there's not much pet parents can do to prevent pollens or other natural allergens from entering windows or crossing paths with their dogs. If your dog has seasonal allergies, Benadryl could be a good option to use before your walks.

You can also use Benadryl for dogs with skin allergies in many cases.

2. Preventing Allergic Reactions

It may also be used as a pre-medication for dogs prone to allergic reactions to vaccinations. If you know your dog is allergic to something that could be in your environment, you can use Benadryl in advance to prepare them.

If you're not sure whether or not your dog is allergic to certain vaccines, for example, you could consider giving them an antihistamine before their shot just to be safe.

3. Nausea and Car Sickness

Benadryl may also be used to prevent nausea from car sickness, although it is less effective than other antihistamines and anti-emetics like Dramamine and Cerenia, respectively.

Because it does have a mild sedative effect, it is also used as a sedative for travel or stressful events. However, Benadryl does not have any anti-anxiety effects, making it a poor choice for the management of fear and anxiety in dogs.

Dogs respond differently to Benadryl as well. Some dogs have the opposite reaction and become more hyperactive after taking Benadryl.

4. Short-Term Allergy Relief

Many dogs also develop a tolerance to Benadryl over time, so it may not be an appropriate choice for long-term use. Additionally, in cases of acute allergic reactions, faster-acting prescription medications like cortisone may be necessary for immediate relief.

Benadryl Dosage for Dogs

The dose of Benadryl in dogs depends on your dog's weight and the desired effect. Consulting a veterinarian is crucial to determine the correct Benadryl dosage based on your dog's symptoms and weight.

The correct Benadryl dosage is essential to avoid potential side effects and overdose. Knowing how much Benadryl to give your dog can prevent adverse reactions and ensure effective treatment.

Before giving your dog Benadryl, it’s best to consult your veterinarian to determine the correct dosage. This is also a good time to let your veterinarian know what is going on with your dog – itching, car sickness, allergic reaction, etc – so that it can be documented in your pet’s medical record.

As you can see, the recommended dose in mg correlates directly to your dog’s weight in pounds. The general rule of thumb is 1mg per lb of your dog’s weight to start with.

In general, you should never give your pet any over-the-counter medications or supplements without first consulting your veterinarian for advice. This is particularly important if your pet has any health conditions or if your pet is on any medications which could interact with the medication you wish to give.

The correct dosage could change depending on the variety of Benadryl you're using for your dog as well, making things more complicated. A liquid Benadryl dosage look different than the dosage for Benadryl tablets, for example.

How Often Can I Give My Dog Benadryl for Itching or Other Allergies?

It's generally suggested that you can give your the appropriate dosage of Benadryl every 8 to 12 hours. That means you should not give it to them more than 2-3 times per day. 

What Happens if I Give My Dog Too Much Diphenhydramine?

A wide range of significant side effects can occur if you give your dog too much Benadryl.

These serious symptoms include:

• Sedation, sleepiness, lethargy

• Loss of coordination (ataxia)

• Increased thirst and dry mouth

• Accelerated heart rate (tachycardia)

• Hyperactivity

• Vomiting

• Increased sensitivity to light (dilated pupils)

• Seizures (as discussed previously)

• Confusion

If you have given your dog too much Benadryl and notice these symptoms, contact your veterinarian right away. Do not induce vomiting unless instructed to do so by your veterinarian.

Keep close tabs on your dog's symptoms and report them to your vet specifically. If possible, get to an emergency veterinarian as soon as possible to prevent serious health conditions.

Preventing Benadryl Overdose

1. Follow Standard Dose Rules

   The most important step in preventing overdose is getting informed on the correct dosage range for your dog. View the Benadryl dosage chart listed above, and don't assume that you can use more before speaking to a trusted professional.

   Dog weight correlates directly with the dosage amount, so pet parents should weigh their dogs before deciding on a dosage.

2. Make Sure Your Dog Can't Access The Package

   Many times, dogs overdose on medications because they break into the pantry. Take serious precaution to keep all dogs away from medications, regardless of what kind. Both larger dogs and small dogs can be harmed by certain medications, especially if they take more than an entire dose meant for humans.

   Consuming excess amounts of medications can cause extreme damage to the brain, terrorize the central nervous system, cause seizures, and even lead to death.

What to Do if Benadryl Doesn't Work for Your Dog

Benadryl can help with mild itching and inflammation in dogs and may be useful as a mild sedative in certain situations; however, Benadryl may not be strong enough to ease your dog’s discomfort. For dogs experiencing motion sickness, other medications like Dramamine may be more effective.

If this is the case, it’s best to see your veterinarian for an examination. Your veterinarian will take a thorough history and perform a full head-to-tail examination. Your veterinarian may recommend some additional diagnostic testing to determine the underlying cause of your dog’s discomfort.

Once your dog’s condition has been appropriately diagnosed, your veterinarian will develop a comprehensive treatment plan including prescription medication if necessary.

Types of Benadryl That are Not Safe for Dogs

Some formulations of diphenhydramine contain decongestants or other medications to aid with colds and allergic symptoms in humans. These medications are NOT safe for dogs and should not be given to your pets.

If you choose to give Benadryl to your dog, make sure you purchase the original formula only, as this does not have added medications.

What Are The Benadryl Side Effects in Dogs?

The main side effect of Benadryl in dogs is mild sedation. This is sometimes the desired effect when Benadryl is used for travel or stressful events, but some owners dislike seeing their pet groggy and “out of it."

Other side effects from Benadryl administration can include:

• Agitation (particularly at higher doses)

• Behavioral changes

• Loss of appetite

• Vomiting

• Constipation

• Diarrhea

• Dry mouth

• Dilated pupils

• Elevated heart rate

• Hypersensitivity reactions

Conclusion: 

Benadryl is generally safe and effective for dogs with mild itching and allergy symptoms, and for use as a mild sedative. 

However, you should always consult your veterinarian prior to starting any new medication for your dog. You should also consult your vet if your pet’s symptoms persist despite the use of Benadryl, as a stronger medication may be necessary to manage your pet’s condition. 

Do not use Benadryl if your pet has underlying health issues or takes medication that may react with Benadryl. If your dog experiences side effects from Benadryl, stop giving the medication and contact your veterinarian right away for further advice.

References:

https://my.clevelandclinic.org/health/drugs/21223-antihistamines
https://www.drugs.com/diphenhydramine.html
https://www.drugs.com/mtm/dramamine.html
https://www.drugs.com/pro/cerenia.html
https://www.hillspet.com/dog-care/healthcare/bph-and-enlarged-prostate-in-dogs
https://www.petpoisonhelpline.com/poison/decongestants/
https://vethelpdirect.com/find-a-vet/
https://lolahemp.com/blogs/pet-health-and-wellness/medications-for-dogs-with-anxiety?_pos=1&_sid=1065eedef&_ss=r
https://lolahemp.com/blogs/pet-health-and-wellness/inflammaging-5-natural-remedies-for-inflammation-in-dogs?_pos=1&_sid=625229740&_ss=r
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