Is Benadryl Safe For Dogs? -
Is Benadryl Safe For Dogs?

Is Benadryl Safe For Dogs?

Benadryl is a popular over-the-counter medicine with dog owners and even veterinarians. But should you really give it to your dog? It’s an often-asked question online …

Can I Give My Dog Benadryl?

It’s best to avoid Benadryl for your dog. Benadryl isn’t safe for dogs (despite what your vet and many websites say). It’s an antihistamine that can relieve allergies in dogs (and people). Vets even recommend Benadryl for anxiety, bee stings, car sickness or reverse sneezing in dogs. But there are several reasons Benadryl isn’t safe for dogs … and there are many safe, natural alternatives.

Immediate Help For Your Dog

First, in case you need help right now for your dog  .. here’s advice on Benadryl alternatives for different situations. 

But if you still need to be convinced about the risks of giving Benadryl to your dog, please continue reading below to learn about …

  • How Benadryl works
  • Potentially serious Benadryl side effects
  • Likelihood of Benadryl overdose
  • Dogs with certain conditions who should never take Benadryl

Home Remedies To Use Instead Of Benadryl

Here are some alternatives to Benadryl to manage conditions that Benadryl is often used for. First, the most common … allergies.

Home Remedies For Allergies

Allergies can be complicated and you may need your holistic vet’s help in figuring out the cause … whether your dog has food allergies or they’re triggered by something else. Here are some natural approaches that can work well.

Colostrum is a substance in mother’s first milk that helps build a newborn’s immune system. It can help your adult dog too … by.strengthening his immune system and help with many types of allergies, including seasonal allergies or environmental allergies. You can give ¼ tsp of powdered colostrum per 25 pounds of body weight.

RELATED: Find out about the top 5 benefits of colostrum for dogs … 

Quercetin is known as “nature’s Benadryl” because it can stop the body from releasing histamines.  Quercetin is naturally found in many berries as well as apple skin. For every 10 lbs of body weight, your dog can have 80 mg of quercetin powder.

RELATED: Learn what else quercetin can do for your dog … 

Medicinal mushrooms have high beta-glucan content that strengthens your dog’s immune response and can help prevent allergic responses and inflammation. Mushrooms like reishi, shiitake, cordyceps, turkey tail and maitake are all good choices. If you buy whole mushrooms, cook them first as raw mushrooms can be indigestible for your dog.

Or, choose a mushroom supplement made from whole mushrooms (not just mycelium, a part of the mushroom) and look for one with a certificate of analysis showing minimum 30% beta-glucan content. Follow the manufacturer’s dosage instructions. If it’s made for humans, assume dosing is for a 150 lb person, and adjust for your dog’s weight.

RELATED: Read how mushrooms help your dog’s immune system …

Home Remedies For Insect Stings

Plaintain leaf juice will soothe stings and bites.  If you’re out on walk and your dog gets stung, you can find a plantain plant just about anywhere. Break off a leaf and chew it a little to release the juice … then rub the chewed leaf on the sting. You can even just rub a leaf directly on the sting.

Baking soda made into a paste with a little water can also help sooth a bite or sting.

And there are two homeopathic remedies that work well for insect bites and stings. These are good remedies to carry on a hike or walk in the woods … and you can take them yourself if you get stung. Buy a 30C potency, available at most health stores. Try Ledum palustre if the bite is cold and puffy. Apis mellifica works well if the area is red and swollen, with a lot of itching.

How to dose: homeopathic remedies come in little pellets. Tip 2-3 pellets directly from the container lid into your dog’s mouth. For bites and stings, give a dose every 15 minutes for an hour. If the first remedy doesn’t make you dog more comfortable in that time, try the second one.

Home Remedies For Anxiety

For anxiety, CBD oil from the hemp plant (not marijuana) is especially effective. Buy an organic full spectrum CBD oil with the different cannabinoids … CBD, CBA, CBC, CBN and CBG. Together, these cannabinoids provide the “entourage effect” that can really help your dog.

For anxiety, you can give your dog 1 to 6 mg CBD per 10 lbs of body weight (check the amount per dropper of the product you buy).  Don’t be afraid to increase the dose a little if your dog doesn’t relax.

RELATED: Find other herbs that can help with your dog’s anxiety …

Home Remedies For Car Sickness

For motion sickness, you may be able to desensitize your dog to the nausea or anxiety he gets in the car if you take him on a lot of short trips.

Ginger, peppermint or fennel tea are all herbs that make great teas for nausea. Make a tea and let it cool, then give it to your dog 30-60 minutes before a car ride. Give 1 Tbsp per 20 pounds of body weight to stop your dog feeling queasy in the car.

If your dog gets car sick because he’s nervous, try some other herbal remedies that help with anxiety.

RELATED: Read about more ways to help your dog with car sickness … 

How To Help Reverse Sneezing

Reverse sneezing is a throat spasm that causes your dog to suck air in through his nose instead of pushing it out of his nostrils. Many veterinarians will recommend Benadryl for reverse sneezing because they believe it’s an allergic reaction. Benadryl may stop a reverse sneezing attack, but it won’t stop the episodes long term.

Some dogs reverse sneeze when they’re anxious or over-excited. In these cases giving flower essences like Rescue Remedy blend can often help. Distracting your dog with a toy or taking him outside often helps too. Others recommend massaging the throat, or gently covering the nostril to encourage your dog to swallow. 

Reverse sneezing is often a sign of rabies vaccinosis (chronic illness from rabies vaccines), so the best approach long term is to contact a homeopathic veterinarian for help finding the right remedy for your dog. Find one at

Acute Vaccine Reactions

If your dog’s ever had an acute reaction to a vaccine … such as facial swelling, fever, difficulty breathing, or even seizures … vets will often suggest dosing him with Benadryl before his next vaccination. But if your dog’s had a reaction before, it’s more likely he’ll have one (and maybe more severe) with repeated vaccination. So your best approach is to stop vaccinating your dog and don’t risk these problems. 

Instead, do your research on whether your dog really needs another vaccination. It’s likely that vaccines your dog’s already had will protect him for life.

RELATED: How to boost your dog’s natural immunity … 

So … in an emergency, you now have some options to use instead of Benadryl. When you get time, though, it’s a good idea to read the background information below to learn why Benadryl isn’t good for your dog.

What Is Benadryl?

Benadryl is the first prescription antihistamine approved by the FDA. It was approved in 1946, just three years after chemical engineer Dr George Rieveschl invented it (Benadryl is the brand name for diphenhydramine hydrochloride).

These days there are many generic versions of Benadryl, including one for pets, called Vetadryl.

Along with being an antihistamine, Benadryl is also an anticholinergic (drying) medicine, and has sedative effects. That’s why it makes most people sleepy, and is used as a calming medicine for animals.

How Does Benadryl Work?

Benadryl is an antihistamine that stops the effects of histamine. Histamine is a natural chemical in the body. Its primary job is as a messenger in the nervous system. It’s also a part of gastric acid, helping the digestive process. And It helps dilates blood vessels as part of your dog’s immune response.

Too much histamine can cause problems like food sensitivities, allergic reactions and damaged capillaries. This damage leads to itchiness and inflammation. So what Benadryl does is block H1 histamine receptors in your dog’s body, stopping the histamine reactions.

That means it works by suppressing your dog’s symptoms … not by curing the underlying disease. So Benadryl may make your dog feel better for a while, but your dog still has the same problem, and the itching or other symptoms will come back.

Holistic veterinarians warn that when you use drugs to suppress symptoms, you drive the disease deeper into the body. But it usually resurfaces … often in a worse form than before.

Side Effects of Benadryl

Most people assume non-prescription drugs like Benadryl are safe. They probably don’t even bother to read the package warnings.  But in 2019 the Canadian Society of Allergy and Clinical Immunology warned against routine use of Benadryl and other “first generation antihistamines,” stating:

“Older AHs have not passed current safety or efficacy standards, and should not be used in routine circumstances for allergic disease.”

They also warned that these drugs cross the blood-brain barrier and “ …and may lead to significant CNS suppression and toxicity resulting in psychomotor impairment, coma, and even death.”

Other Benadryl side effects include …

  • Constipation
  • Cognitive issues, confusion, dementia
  • Anxiety
  • Moodiness
  • Depression
  • Nausea
  • Vomiting
  • Change in appetite
  • Trembling
  • Chemical dependence
  • Dryness of mouth, nose and throat
  • Drowsiness
  • Low blood pressure
  • Heart palpitations
  • Can mask symptoms of gastrointestinal problems

It’s also very easy to overdose Benadryl.

Benadryl Overdose In Dogs

Too much Benadryl can have dire consequences, because dosing has a very narrow safety margin. Overdose signs like these can show up within an hour …

  • Red eyes or dilated pupils
  • Fever
  • Lack of coordination, inability to walk
  • Delirium
  • Intense drowsiness
  • Rapid heart rate
  • Difficulty urinating
  • Seizures
  • Muscle tremors
  • Aggression
  • Difficulty breathing

If you see these serious signs in your dog, take your dog to the emergency vet. 

Never Give Benadryl To These Dogs

Benadryl is especially unsafe for dogs with these conditions: glaucoma, heart failure, seizures, prostatic hypertrophy, bladder neck obstruction, allergic lung disease or hyperthyroidism (which is rare in dogs).

You also shouldn’t give Benadryl to pregnant or nursing females. 

If You Must Give Your Dog Benadryl

Sometimes emergencies happen and maybe Benadryl is all you have handy. If you ever have to use it, make sure you ask your veterinarian for the correct dosage for your dog. Don’t guess … because it’s really easy to overdose Benadryl and cause severe illness.

But now you have some home remedies to turn to … so stock up on these natural solutions instead of grabbing that little pink pill from the medicine cabinet.


Fein, M.N., Fischer, D.A., O’Keefe, A.W. et al. CSACI position statement: Newer generation H1-antihistamines are safer than first-generation H1-antihistamines and should be the first-line antihistamines for the treatment of allergic rhinitis and urticaria. Allergy Asthma Clin Immunol 15, 61 (2019).

de Mello Schier AR et al. Antidepressant-like and anxiolytic-like effects of cannabidiol: a chemical compound of Cannabis sativa. CNS Neurol Disord Drug Targets. 2014;13(6):953-60. 

Schultz RD. Duration of immunity for canine and feline vaccines: A review. Veterinary Microbiology. 2006;117(1):75-9.