How much Benadryl can you give a dog?

If your dog is suffering from some allergy then you must have thought about giving your dog Benadryl. But the question is how much benadryl can you give a dog. It is common for us humans to take Benadryl in order to treat our allergies. In fact, its availability as an over-the-counter drug makes it a convenient choice for us. But is it safe for dogs?

No matter what allergy is bothering your dog, it is always safe to consult the vet first. If you give your dog anything without any vet’s prescription then it can cause more harm than good. Since Benadryl is something that is over-the-counter drug makes it hard for the dog owners to take the right decision.

If your dog is showing actual signs of allergies and discomfort, only then you should go for Benadryl. And while giving Benadryl, keep in mind the dosage prescribed by a certified vet.

The dosage can depend on different factors. In order to know more about Benadryl and its effects on your pooch, follow this guide given below. You’ll become aware of its effects as well as benefits and side-effects that the drug can cause.

What does Benadryl do for a dog?

Benadryl is an antihistamine available over-the-counter to calm the allergic reactions caused by allergens, insect bites etc. The allergies can also be caused by some vaccine reactions. So, Benadryl is used to calm them down.

It can also help with motion sickness and works as a sedative to prevent discomfort. But the fact that it is not FDA approved for dogs makes it not so safe choice. Even though you can use it easily on humans, but for your pet, you need to see the vet.

how much benadryl can you give a dog

Benadryl itself is not the drug that treats allergies in dogs, it’s the active drug named Diphenhydramine that does the work. Benadryl is actually the brand name. When given in prescribed amounts, it can improve the symptoms of allergies in your dog.

While looking for the drug, you’ll come across a lot of drugs under the name of Benadryl. A lot of them are usually fake or contain other chemical compounds that can put your dog at risk. That is why it is always advised to take a vet’s advice before taking any decision.

What are the side-effects of Benadryl?

There are some side-effects of Benadryl for dogs and as a pet owner, you should be well aware of that. No matter how bad the situation gets, always consult a veterinarian before you give Benadryl to your dog. Given below are some of the side-effects of Benadryl on your pooch.

  • Severe heart failure
  • Angle-closure glaucoma
  • Hypertension
  • Prostatic hypertrophy
  • Bladder neck obstruction
  • Pregnancy
  • Allergic lung disease
  • Seizure disorders
  • Dry mouth
  • Hypersalivation
  • Diarrhea
  • Vomiting

There are many other side-effects like rapid breathing that you should look out for. It is also observed that some side-effects start showing up within the first few hours of intake.

When is the Benadryl most harmful to dogs?

Even though Benadryl is a drug commonly used to treat allergies in dogs, there are some situations in which it can actually do some harm. Given below are the situations in which you should be concerned.

  • Any medical condition

If your dog has any medical issues such as high blood pressure, glaucoma, heart diseases, and many similar situations then you should avoid giving your dog Benadryl as the situations can worsen with it.

  • Allergic reaction

Even though it is an antihistamine, it can still cause allergic reactions in some dogs. So, watch out for the signs if you start the dosage.

  • Overdose

This is something that you should avoid, no matter what the situation is. An overdose of Benadryl in dogs can lead to lethal consequences. If something like that happens, take your pet immediately to the vet. The symptoms of overdose include seizures, dilated pupils, constipation etc.

  • Pregnancy

When a dog is going through pregnancy, you should never give it Benadryl without asking a vet.

  • Side-effects

When it comes to the side-effects, then there are many as mentioned above. So, if you see any of those symptoms in your dog, then it might be because of the drug. So, make sure that you consult a vet in a situation like that.

How much Benadryl should I give my dog?

Generally, the dosage largely depends on the dog and its physical condition. If your dog is suffering from any medical condition then we would not recommend you giving your dog Benadryl. But if you are looking for standard dosage then you should know that the standard oral dosage of Benadryl is 1 mg per pound of weight of the dog. You can give the drug 2-3 times a day.

If the dog is 30lbs and smaller then you should give 10mg per dosage. Similarly, if the weight is between 30-50lbs then it is 25 mg per dosage and if the weight is more than 50lbs or more then you should give 50 mg per dosage. Following this pattern will allow you to efficiently use the drug so that it can show some results and not cause any harmful side-effects.

When you go to the drug store, you’ll find that the available amount of diphenhydramine tablets is 25 mg. This is usually for a 25-pound dog. Also, while getting over-the-counter medications, always recheck the dosage to avoid any mishappenings. Following this dosage can help your dog in getting rid of the allergies. So, make sure that you consult a vet for max results.

Is it safe for dogs?

Yes, Benadryl is comparatively safe antihistamine available in the market. Its usage should not cause any inconvenience in the long run. Still, there are some things that should be avoided to keep your pet safe.

  • Combining Benadryl and cold medicines.

Even though Benadryl is safe for your dog, combining it with cold medicine may not be the best thing to do. So, try not to mix Benadryl with other medicines.

  • Not safe for puppies

Before starting any medication on small dogs and puppies, make sure that you consult a vet first. Puppies are sensitive and can’t handle strong medicines as they haven’t developed fully.

  • Side-effects

As mentioned above, if your dog already has conditions like glaucoma, heart conditions, etc. then ask your vet before you give your pet Benadryl.

  • Avoid Sodium

It has been noticed that some formulas of Benadryl contain sodium. Now, as a pet owner, you should know that sodium intake can be harmful to your dog if it is having any health condition. So, just to be safe, avoid sodium.

Apart from all these factors, Benadryl is a safe drug and its right usage can actually benefit your dog. Try not to exceed the standard dosage and you’ll be fine.

How much liquid Benadryl to give my dog?

One of the most common questions that people ask is how much Benadryl can they give their dog in liquid form. This question arises when people don’t know about the harmful effects of liquid Benadryl on dogs. You should know that Benadryl in liquid form contains a high content of alcohol, which is not safe for your pet. So, before giving Benadryl in liquid form to your pet, ask your vet. Sometimes, liquid Benadryl can cause more harm than good.

How to give Benadryl to my dog?

  • Start small

When it comes to seeing results, you can’t really force your pet. While giving Benadryl for the first time, make sure that the dosage is smaller than standard. This way you can see its possible effects on your dog and test it if it actually works or not. This way you can also study possible side-effects on your dog.

  • Accompany with food

In order to avoid any side-effects, Benadryl should be given with food. You can use dog treats or the entire meal to give your dog Benadryl. This is something that vets recommend.

  • Hide the medicine in food

If your dog is not very fond of tablets, then you can hide them in the food where they can’t see it. Try breaking the tablets into two.

How long does Benadryl last for dogs?

When it comes to the effects of Benadryl, surprisingly, we can be sure about its effects. Benadryl is a drug that gets absorbed easily and very quickly. It takes only 30 minutes to see the effects. If your dog has been suffering from any allergies, then it can help in getting rid of them in a small period of time.

Also, if your dog is scared of something or hyperactive then the drug can also help in calming down the nerves and helping your dog relax. Usually, the effects of Benadryl last anywhere from 4 to 6 hours.

Will Benadryl make my dog sleepy?

It is said that Benadryl is a safe drug, but still, there are some side-effects that make it not so perfect choice for some pet owners. Another most common question that arises is “will Benadryl make my dog sleep?”

You should know that one of the most common side effects of Benadryl is drowsiness. Even though the side-effects of this medication are on the mild side, but still drowsiness is something which is frequently reported by the pet owners who have fed their dogs Benadryl. But some think that this is better for their dog because then their dog calms down easily.

How much Benadryl for a dog to go to sleep?

When it comes to the side-effects, you can’t really judge unless you try the medication. Now, if you want to know how much Benadryl to make your dog sleep, then you should know that this is a mild side-effect which comes into light when you are following the standard dosage of Benadryl. If the dosage is correct, only then this side-effect will show up. If you overdose your dog, then the side-effects might be different. But it is reported that the standard usage of Benadryl cause sleepiness in dogs and some also use it to calm down their dogs.

Can I give my dog Benadryl for the itching?

As mentioned above, Benadryl being an anti-histamine can really help with the itching in your dog. Benadryl is safe and can treat itching caused by skin allergies. Since, it is safe and over-the-counter, the chances of it getting a misused increase. That’s why take a recommendation from a certified vet before starting any kind of medication. So, if your dog itches too much because of allergies, then you can easily give your dog Benadryl. It works within hours and provides comfort to your dog.

Can you overdose your dog on Benadryl?

Yes, you can overdose your dog on Benadryl. In fact, the overdose in dogs can lead to serious health issues. The signs of OD include hyper-excitability of the central nervous system of your dog. This issue can be fatal and cause serious harm to your dog. In such cases, you should take your dog immediately to the vet. There are many other symptoms of overdose. Some of them include seizures and dilated pupils etc.

How much Benadryl is too much for your dog?

If you are not following the standard amount and giving your pet more, then it can be considered as too much. The dosage of oral Benadryl is an mg per pound of the dog’s body weight.


Overall, we can say that Benadryl is not that bad when it comes to treating your dog’s allergies. There might be some side-effects, but that shouldn’t be a problem if your dosage is right and your dog doesn’t have any other medical condition. Still, we’d recommend you to go to a vet before taking any decision yourself. This way you can avoid any possible side-effects of Benadryl and take full advantage of anti-histamines anti-allergenic properties. Benadryl is a safe drug and help your dog in getting rid of allergies in no time.