Giving Dogs Benadryl, Is it Safe?

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Is giving dogs Benadryl safe?  – Giving dogs Benadryl is safe as long as you use it carefully, and your dog doesn’t have a pre-existing medical condition. It’s also advisable to check with a vet before giving it to your furry best friend.

Giving Dogs Benadryl  – What is it?

You can usually find Benadryl at your local drug store. It’s an over-the-counter medication that is used to treat mild to moderate allergy symptoms in people.

Benadryl tablets

Diphenhydramine HCL is the active ingredient in Benadryl and is a first-generation antihistamine used to combat:

  • The common cold
  • Hay fever
  • Food allergies
  • Environmental allergies
  • insomnia

Benadryl as an Antihistamine for Dogs

Benadryl as an antihistamine for dogs is particularly effective in easing the following common allergy symptoms:

  • Anaphylactic reaction
  • swelling
  • Watery eyes
  • Runny nose
  • Hives
  • Inflammation of the Skin
  • Coughing
  • Sneezing
  • Itchiness

Another alarming symptom is when you see your dog reverse sneeze, Benadryl is very fast at calming the condition. This rapid action gives your dog some much-needed relief.

Histamines are produced in the body whenever it detects something we are allergic to.

Diphenhydramine is used in this case as an antihistamine for dogs. It works by blocking receptors in the body that receive histamines consequently preventing the body from creating unpleasant allergy symptoms.

Common side effects are:

  • Dry nose
  • Headache
  • Dry mouth
  • Drowsiness.
  • Dry throat

Although uncommon, other side effects of first-generation antihistamine for dogs are:

  • Trouble urinating
  • Pain with urinating
  • Vision problems
  • Constipation
  • Nausea
  • Chest congestion
  • Dizziness
  • Loss of appetite

Benadryl to calm Dog Anxiety

Medications like Benadryl have a mild sedation for dogs that is perfect if your best friend is of a nervous disposition.

wild-eyed dog

It is usually given as a safe sedative for dogs, to temporarily calm dog anxiety in certain situations such as:

Timing the dosage is also an important element in giving Benadryl for dogs, fireworks is a one good example of this.

Imagine it’s Halloween, and you know a neighbor lets off fireworks around a particular time, take action. Make sure your best friend sedated before the noise even begins.

If using Benadryl as a safe sedative for dogs, make sure you know the correct dosage for your dog.

Benadryl as a mild sedation for dogs when Travelling

Giving dogs Benadryl before travelling is often done to relieve motion sickness in dogs during car or plane rides.

Another more common reason is in relation to dog travel anxiety, Benadryl in this case can be extremely helpful.

Anxious dogs that have to travel long distances benefit from one of Benadryl’s handy little side effects. Benadryl is very good at making dogs drowsy and putting them in mild sedation.

Giving dogs Benadryl - Dog sedated in a car

Nervous dogs that are locked in a tin box on wheels while traveling at high speeds are unpredictable. An anxious dog can pose a significant danger to anyone traveling in the same vehicle. Giving an anxious dog Benadryl under these circumstances can seem like a positive solution.

Can you give a pregnant dog Benadryl?

In the same way that we try not to give pregnant women unnecessary drugs, that same rule of thumb applies to pregnant dogs.

In cases where a pregnant dog has a condition that requires medication, you should always consult a vet. Do make sure that you inform the vet that your dog is currently pregnant. This vital information will almost certainly affect the medication your vet prescribes.

Giving Dogs Benadryl – Is Benadryl Safe for Dogs?

Giving dogs Benadryl is considered safe when used sparingly and as long as there are no pre-existing medical conditions.

Although Benadryl hasn’t been FDA approved for veterinary use, vets across America use it all the time. It’s considered safe for both dogs and cats.

It is recommended, however, that you seek the advice of your vet before giving dogs Benadryl. The reason is that symptoms pointing to an allergic reaction could in fact be something completely different. Only your vet is qualified to know the difference. Giving your dog Benadryl under these circumstances could make your dog’s condition considerably worse.

How many ml of Benadryl for my dog?

The standard dose of Benadryl to dog ratio is 1 mg per pound of body weight. Speak to your vet to get a better idea of the correct dose according to the size of your dog.

You can also use this Benadryl for dogs calculator here

Or, check out our handy Benadryl dosage chart for dogs

Benadryl Dosage Chart

Is it Possible for Dogs to Overdose on Benadryl

It’s very important to get advice on using Benadryl from a vet before giving it to your dog. Especially if you’re not sure if your dog has an allergy, or your best friend has some other condition with similar symptoms.

Dogs can suffer allergies and seizures or overdose on Benadryl, and it can be fatal.

Watch for the warning signs:

  • Hyper-excitability of the central nervous system
  • Enlarged pupils
  • Anxiety
  • Increased heartbeat
  • Constipation
  • Convulsions

Benadryl Liquid for Dogs

Don’t give Benadryl liquid to your dog as it’s extremely toxic to your furry best friend. This is because Benadryl liquid for dogs contains alcohol.

The Benadryl liquid for children, however, is a totally different prospect. The children’s version of the liquid contains no alcohol whatsoever and is less concentrated. This lower concentration form gives it a lower dosage range and makes it suitable for small dog breeds.

Benadryl Cream for Dogs

Benadryl cream for dogs is okay to use on problems such as hives, bee stings, and vaccine reactions. However, Benadryl cream for dogs doesn’t really work well on atopic dermatitis.

For mild cases, you’re better off using other types of antihistamines such as:

  • Clementine
  • Loratadine
  • Hydroxyzine

For more serious atopic skin conditions, you’ll have better results using Cortisone

Benadryl Spray for Dogs

So, can I use Benadryl spray on my dog? Benadryl spray for dogs should only be used in emergencies, and only ever as a last resort.

It’s very risky giving dogs Benadryl in spray form as you cannot control the dosage and it could make matters worse for your dog.

Never spray on an open wound, insect sting/bite, or allergic rashes. This can burn and leave lasting damage to your dog’s healthy tissue.

Only ever use Benadryl spray if your dog’s life is in danger and all other alternatives are unavailable.

For example, imagine a nightmare scenario where your dog is having an allergic reaction and is struggling to breathe. Your miles away from help with no phone signal and your furry friend is in distress and getting steadily worse.

In this sort of situation, you’ve got nothing to lose. Time is limited and you’ve run out of options. It’s a risk, but using the Benadryl spray could save your dog’s life.

Nevertheless, in most normal cases, get your dog to vet ASAP.

Giving Dogs Benadryl – Side Effects in Dogs

The possible side-effects of over-the-counter medication are becoming an increasing concern for dog owners. Many of us wonder if the side-effects of these medications are worse than the original condition we’re treating. With this in mind, what are the side effects of Benadryl in dogs, and are they serious?

Check following side effects of Benadryl in dogs here, before reaching for the medicine cabinet.

If your dog experiences an acute allergic reaction such as facial swelling or difficulty breathing, rush your dog to the vet. 

Don’t try giving dogs Benadryl in combination with other drugs unless your vet has authorized it. This could be extremely dangerous for your dog.

Also, if your dog suffers with any of the following conditions, DO NOT give your dog Benadryl:

  • Glaucoma
  • Severe heart failure
  • Pregnant
  • Lung disease
  • Hypertension

Giving Dogs Benadryl – FAQ

Q – Can you crush Benadryl and apply to skin?

A- No, you shouldn’t try applying antihistamines directly through the skin. If treating hives or itchy skin symptoms, can irritate the skin further. Applying Benadryl through the skin also makes it very hard to control the dosage correctly.

Q – Can Benadryl kill my dog?

A – Some formulations may include Tylenol or Phenylephrine and can be fatal to dogs. Make sure that diphenhydramine is the only active ingredient. Check the label carefully. 

Q – What do Benadryl pills look like?

A – The Benadryl Diphenhydramine pills are capsule shaped, pink in color and have a strength of 25mg.

Q – Is Benadryl an anti-inflammatory drug?

A – The Diphenhydramine contained in Benadryl gives it anti-inflammatory properties. It works well with painful severe swelling, however, Benadryl is not recommended for minor swelling.

Q – Is Banophen the same as Benadryl?

A – Yes, Diphenhydramine is sold as both Benadryl and Banophen, however, it’s advisable to check the dosages before using, as there may be differences.

Q – Can I give my dog Benadryl capsules?

A – Never give time-release capsules to dogs. Capsules are assimilated differently in people than dogs. Capsules can easily break when chewed, releasing too much medication all at once and putting your dog at risk of an overdose.

Q – Do I give Benadryl to my dog on an empty stomach?

A – No, always give Benadryl to your dog with food. You can even mix it in with his usual meal.

Q – How long does it take to see the effects

A – It usually takes about 30mins for the full effects of Benadryl to show in your dog.

Q – I don’t like giving chemical medications to my dog, are there substitutes for Benadryl?

A – Yes, and we have a detailed article about natural alternatives to Benadryl that may help.

Giving Dogs Benadryl – Tips to reduce allergies in dogs

Invest in a high-quality air purifier to reduce air pollutants

  1. Do not smoke around your dog
  2. Do not allow your dog to receive too many vaccines or medications to not over stimulate their immune systems
  3. Switch to organic/non-toxic cleaning products
  4. Give Probiotics to significantly reduce and prevent allergies
  5. Avoid feeding the most common food allergies in dogs which are dairy, beef, chicken, wheat, and eggs
  6. Add leafy greens and canned sardines to your dog’s diet
  7. Use colloidal oatmeal shampoo or add ground oatmeal to its shampoo
  8. Do not use head and shoulders shampoo on your dog, it’ll dry out and alter the PH of the skin, and the scent is too strong for a dog’s sensitive nose
  9. Use Homeopathic medicine to treat allergies


While giving dogs Benadryl can be a good solution for many owners, it does come with the added hazard of side effects.  This only gets worse if you accidentally overdose your dog.

vet examining Dog

Knowing the dosage is essential, and if your dog has health problems or you have any doubts about using it, then always seek your vet’s medical advice first.

There are many natural options that you can use that have fewer potential issues for your dog. We highly recommend that you explore these alternatives before rushing to the medicine cabinet. We have a detail article that explores natural alternatives to Benadryl, you can find it here.

All information in this post is for educational purposes only and is not meant to replace your veterinarians’ advice.

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Benadryl for dogs - a Pinterest pin showing two images, on image shows a dog unconscious on the floor while the other shows pink Benadryl pins

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All information in the article is for educational purposes only and is not meant to replace your veterinarian’s advice


All information in this article is for educational purposes only and is not meant to replace your veterinarian's advice.
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