Benadryl for Dogs – What is it and what kind should I get?

In Dogs, Pet Health by Emotional Pet Support TeamLeave a Comment

Spring season may be the most pleasant in the year, but it’s also the season for some pretty gruesome allergies. Some include sneezing, coughing, runny eyes, and runny nose. If your dog is joining you in this allergy-induced misery, don’t make the mistake of just giving them a dose of your trusty Benadryl unless you know the ins and outs of the drug because there’s actually a version of Benadryl specifically designed for just dogs.

If your vet has approved its use, you can give your dog Benadryl. Benadryl’s active ingredient is diphenhydramine, an antihistamine, that’s both effective and safe for canines. It treats a few things in dogs, including nausea, minor anxiety, and allergies.

But do understand that the FDA does not approve the use of Benadryl for dogs due to the trust of dog owners, but if you use the correct amount, it is no harm. Here are some important points to keep in mind while using this medicine:

What is Benadryl for Dogs?

In a nutshell, it is mainly a drug that is also known as Diphenhydramine drug. According to PubChem, its molecular formula is C17H21NO.


Histamine is treated by using this medicine. This medication helps only after the effects of allergy have started. If the allergy symptoms are not being expressed, then it won’t do you any good to use it anyway. It helps in decreasing the redness of the nose, watering eyes, and loss of appetite.

Is Benadryl Safe for My Dog?

Benadryl is incredibly safe for dogs that are free from pre-existing health conditions. You should still consult with your vet before dosing your dog because there are some associated safety recommendations. First, some medications do interact negatively with diphenhydramine. The list can vary, and your vet will know if your dog’s current medications fall into this category. Dogs with cardiovascular disease, glaucoma, hyperthyroidism, or prostate disease shouldn’t have Benadryl and will need an alternate medication.

There are a few Benadryl formulations that aren’t safe for dogs. The first is the liquid form. It might be easier to administer, but it’s quite high in its alcohol content, making it quite bad for them. You should also keep an eye on the label’s active ingredient. If there’s anything besides diphenhydramine listed as the active ingredient, then your dog should definitely not have it.

How Do I Give Benadryl To My Dog?

You can insert it in the dogs’ body in many forms. First of all, you can take a standard teaspoon size of 5 mL and after taking proper measurement give it to your dog. It is suggested not to use alcohol while turning it into liquid. Five mL amount of liquid Benadryl holds diphenhydramine of 12.5 mL. Secondly, the dogs that dislike the taste of liquid medicine, tablets are recommended.

The amount of Benadryl that should be given to your dog depends on the weight of the dog. The third form is to inject the medicine. It is used when the airway to the stomach of your dog is blocked by the intense allergy. Normally it is injected into the muscle tissues of dog, under his skin or into the blood vessel. Not only are these three forms available. You can also use it in the form of a gel, spray, cream, etc. but these forms include less amount of medicine in them.

How Long Does It Take To Work?

The approximate time for Benadryl to start working is roughly 30 minutes. Be sure to monitor your dog properly before and after applying the medication.

What Is The Proper Dosage Of Benadryl For A Dog?

Benadryl dosage for dogs usually depends on the dog’s body weight. Benadryl is an effective drug but the amount of consumption should be properly measured before administered.

It’s too low dosage is also not effective. So the amount of Benadryl given to dogs should be measured and prescribed.

The amount of Benadryl dosage in accordance with the dog’s body weight is given below:

According to PetMD, a dog should only have 1 mg of Benadryl for 1 lb. of the dog’s weight.

But more convenient amounts of dosage suggested by doctors are,

  • 10 mg of DPH for 30 lb dog
  • 25 mg of DPH for 30 to 50 lb dog
  • 50 mg of DPH for 50+ lbs. every 8 hours.

Benadryl will be effective when you will give it to your dog 3 times a day. You could also inject Benadryl into your dog.

What Happens If My Dog Has Too Much Benadryl?

No matter how safe Benadryl is, if it’s given in too high of a dose, your dog will suffer from it. An overdose can be mild or it can be severe; it all depends on how much you’ve given and your dog’s current health.

According to the American Kennel Club (AKC), the effects of an overdose with this medication are:

  • Rapid heartbeat
  • Dilated pupils
  • Agitation
  • Constipation
  • Seizures

To prevent an overdose, always double-check with the other people in your household to ensure they haven’t already given your dog their dose. Keep the medication out of reach of your dog; while you think it wouldn’t be appetizing to a dog, sometimes they’ll eat things out of boredom.

Major Side Effects of Using Benadryl for Dogs

It is not such a harmful drug because it is used only for treating small allergies that are not such a big issue. But it is probable that it may cause some of the side effects.

Some symptoms are listed here:

  • Drooling
  • Lethargy
  • Odd behavior
  • Excitability
  • Increased breathing rate
  • Reduced rate of urination
  • Dry mouth
  • Diarrhea
  • Depression (tension)

These are some of the common reactions that are caused by the use of this medicine. There are some other symptoms proved with research that may appear in your pet. Those symptoms include loss of appetite, vomiting, diarrhea, nausea, digestive disorders, and allergic reaction if not given in appropriate amounts and situations. If your dog shows such reactions, go immediately to your veterinarian and take the prescribed medicine for healing.


Precaution & Warning

While using Benadryl for dogs, there are certain cautions to keep in mind. If you are visiting a vet, don’t forget to tell him the names of other medicines that your dog is using and also other medical issues like blood pressure of glaucoma.

It is necessary to avoid the wrong outcomes. The dogs suffering from liver, the heart, and kidneys are at greater risk and complications may arise. Also, avoid the usage of other drugs because it may cause a reaction due to contradicting chemicals present in drugs.


Although Benadryl for dogs is one of the most common drugs. It has multiple interesting usages that need to be well understood before using it.

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