Giving Benadryl to Your Dog — The Complete Guide

Giving Benadryl to your dog: should you do it?

Is it helpful and harmless?

Or is Benadryl for dogs dangerous and a bad idea?

Used properly, in the right situations, Benadryl can be a lifesaver—preventing headaches and alleviating discomfort for your dog.

Before we get started, a disclaimer: it’s always a good idea to talk to your vet about giving medication to your dog. If you can’t make it in for an appointment, try just giving your vet a call to ask their opinion if you’re worried about giving your dog Benadryl.

What Is Benadryl & Where Can You Get It?

Benadryl is a common over-the-counter antihistamine that you can buy at any drug store, pharmacy, or grocery store.

Like other antihistamines, its primary use is to help reduce symptoms associated with allergies such as sneezing and runny nose.

Keep in mind that Benadryl is the brand name for the active ingredient called diphenhydramine. So even if your store doesn’t sell Benadryl, they almost certainly offer a different brand with the same active ingredient. Check the “Drug Facts” on the back of the label and look for diphenhydramine as the Active Ingredient.

Benadryl’s Uses for Dogs

Benadryl absorbs very quickly and usually begins to take effect after about 30 minutes. Benadryl can be helpful if your dog has any of these symptoms:

  • Itchy skin
  • Irritated skin
  • Nausea
  • Car sickness
  • Insomnia
  • Anxiety
  • Insect or flea bites
  • Bee stings
  • Reaction to vaccines
  • Hay fever, sneezing, or coughing
  • Stuffy or runny nose
  • Asthma
  • Allergies
bully max dog food can help with allergies
Bully Max dog food contains no artificial ingredients or fillers. Many customer report a change in their dogs health and well being.

Side Note:  Allergies in your dog can be caused by the type of food you are feeding your dog.

While there are many good hypoallergenic foods on the market, Bully Max offers high quality dog food that can help with your pets allergies.

Dog Food Advisor Rates Bully Max Dog Food 5 Stars.

Is Benadryl Safe for Pets?

Generally speaking, yes.

Benadryl is a relatively harmless drug that should be totally safe for your dog.

But there are a few caveats:

Benadryl might not be safe for puppies. If your dog is a little pup, ask your vet first. Just as you have to be careful giving medications to human babies, you have to be careful with what you give a puppy. They’re small and may not have fully developed

Avoid combination Cold/Sinus medications. Diphenhydramine is safe for dogs—but many of the other cold and sinus ingredients (including fever reducers, decongestants, and expectorants) may not be. Make sure diphenhydramine is the ONLY active ingredient listed on the label.

Steer clear of liquid Benadryl. In liquid form, Benadryl has high alcohol content that will be unsafe for your pet.

It’s counter-indicated with some conditions. If your dog has prostatic disease, glaucoma, cardiovascular disease, or hyperthyroidism, definitely check with your vet to make sure Benadryl is safe for your pet.

Watch for formulas containing sodium. Some Benadryl formulas (such as children’s versions) contain sodium, which could be problematic for dogs with certain health conditions who are taking medications. To be on the safe side, look for a form of Benadryl that does not contain sodium.

Do not exceed the recommended dosage. More details on this below.

Getting the Dosage Right (How Much Benadryl Does Your Dog Need?)

The amount of Benadryl your dog needs depends on its size.

The easy (and less precise) way to determine this is to put your dog into one of three categories:

  • 30 lbs and smaller – give 10 mg per dose
  • 30-50 lbs – give 25 mg per dose
  • 50 lbs and over – give 50 mg per dose

That should give you a fairly accurate dosage.

If you want to be more precise, the formula to do that is to give your dog 1 mg of Benadryl for every 1 lb of body weight.

So a 35-pound dog should get 35 mg of Benadryl per dose. The Benadryl dose for 16 lb dog would be 16mg.

Ask your vet for more help with dosing frequency, but the typical dose is 3 times a day, every 8 hours apart.

Potential Side Effects of Benadryl

Being a safe medication, Benadryl’s side effects are on the mild side.

The most commonly reported side effect is drowsiness. This is so common that many people give Benadryl to their dogs to help them calm down. (Diphenhydramine is even marketed and used as a sleep-aid by many people.)

The second most common side effect is mild disorientation. We recommend paying attention to your dog’s behavior after giving them Benadryl to make sure they don’t experience this before giving them a second dose.

Other, less common side effects include:

  • Dry mouth
  • Breathing problems
  • Diarrhea
  • Lack of appetite
  • Vomiting
  • Agitation
  • Rapid heartbeat
  • Urinary retention (not peeing)

If you think your dog is experiencing any of these side effects, give your vet a call.

Tips for Giving Benadryl to Your Dog

Test it first. Instead of giving your dog a full dose right off the bat, try giving them a small amount of Benadryl and waiting for a few hours. Watch your dog for any signs of side effects or reactions.

Always give it with food. One way to avoid some of Benadryl’s side effects (such as nausea and lack of appetite) is to give it to your dog with a meal or a dog treat.  Bully Max high protein dog food is good for this.  

Break up tablets and put it into a piece of meat. Most dogs are less than eager to swallow a whole pill. But if you break the pill up into chunks and place them inside a piece of meat, your dog will wolf it down without ever knowing there was a pill inside.

Mix liquid gel Benadryl with wet food. If you have a liquid gelcap, try breaking it open and mixing it with some wet food containing gravy. Your dog will never taste the Benadryl (and they’ll love the gravy).



    • That’s correct.

    • brainiac 1900

      My vet told me to only use dye-free Benadryl.

  • Heather

    Can bullymax help with skin irritation? My pitbull (6months) stays inside but goes out to use the bathroom, so we have to bath him quiet regularly. He had also had itchy, red, irritated skin. I use special veterinary hot spot shampoo but it only helps some.

  • kathy barrow

    My brother left the benadryl down and ou dog are 14 benadryl is it going to hurt her

    • We would recommend contacting your veterinarian immediately.


    I have a 145 pound Saint Bernard mix who is having an allergic reaction right now. The vet told me this afternoon to give him prednesone 2x a day and 300mg (!) of bennedryl 3x a day (!)

    I have him 12 25s around 3pm and then another 12 around 10pm… I think the dose was too much! He actually seems to be in less discomfort now, but appears kind of high or drunk.. maybe I’m just projecting what I would expect.. is 900mg/day a safe dose ever??

    • With any medical emergency, we always recommend taking your vet’s advice. In certain situations (such as a snake bite), veterinarians normally recommend 2 mgs per pound of body weight. So the 300mg recommendation makes sense in some cases.

  • Leo

    What about a dog with a cold/runny nose will Benadryl help? At least stop the runny nose? or is there an over the counter medication for dogs with colds/runny nose. ( like at a pet store ) At this time, I cannot afford to take him to a Vet. Looking for a home remedy or an over the counter medication for dogs… Thanks so much for answering.

    • JoJo

      I read some where you can give them robitussin for cough, Pepto/Keopetate for diarrhea, and Dramamine for car sickness. That’s all the “human” meds I can recall.

      • Leo

        Hi JoJo,
        Thank you for replying, after I left that msg/question I continued to do my own research, and found Vibactra !!! All Natural Herbal Antibiotic I will be placing an order. It’s EXACTLY what I was looking for YAY!

  • Melissa granger

    Our dog is a little dog and has the collapsed trachea…so the vet said give him benadryl….he is only 12.5 lbs…can I give it to him everyday? Or is that too much? He wakes up in the middle of the night hacking and kinda sounds like a

    • CrowMeris

      Ask your vet to be certain, but generally yes – you can give it every day, but only as long as he really needs it. Start on half the recommended dose (twelve milligrams/dose for a twelve pound dog) and see if that works (that would be six milligrams/dose or one-quarter of a 25 milligram tablet).

    • Brtall

      That depends on what form you are givng. Liquid or pill. The pill of often 25mg, enough for a 25lb dog. Your dog being 12.5lb’s would need about half the pill, and you can give it to him twice a day. If you have teh liquid form, check how many mg of drug is in a 5ml dose.

      If giving the correct size dose, you should be able to give it to your dog 2 – 3 times a day.

      • Tausha Barker

        Brtall the article above said do not give them liquid Benadryl because it has sodium in it.

        • Lynn Coy

          It said a high alcohol content, not sodium……childrens liquid does not have alcohol in it anyway.

          • paula vallee

            yes the sodium part was about some childrens liquids.

    • Jodi Mickay

      My eldests daughters dog is the same way vet said seasonal allergies. And the noise is said to be get this.. Backwards sneezes!! They started with benadryl one pill one to two times daily. Its been 5 yrs and now the benadryl no longer works and so she is on a steroid med every spring and fall…….

  • Debbie Sidell

    I bought a quickfinder nail clipper because my dog’s nails are ridiculously long and when I tried to clip her nails I didn’t even get near the nail and she bit me. I was wondering if I could give her enough Benadryl to knock her out so I could clip her nails? Any experience or any advice would be really helpful. Thanks!

    • I would not recommend using benadryl as a sedative. Walking your dog on a concrete will do the trick.

  • Amanda

    My dog had reacted to the vaccines about 2 days ago and had a high dosage of benadryl to counteract the swelling in her face. She’s been good now but had started to have diarrhea two days later. Is this normal?

  • Tiffeny

    My dog is having an allergic reaction right now. Shes having a reaction to her rabies vaccination. Within an hour she broke out in hives and has swollen eyes and mouth. Her first dose of benadryl was liquid about 30ml, it helped quickly and she slept for a couple hours. 5hrs later she became itchy and swollen again. I have her another dose, This time chewable tabs ( she fought me with the liquid and I couldn’t get it in her again, plus I read to avoid liquid) it does not seem to be helping as effectively this time, plus she is shaking her head alot. Should I continue with benadryl in another 4 hours? I plan to call vet in the am but I don’t know what to do for the rest of the night. I have a 4yr old female pitbull , she’s about 50 lbs.

    • If the Benadryl isn’t working, I would recommend contacting an emergency vet that’s open 24 hours.

  • Sarah` White

    My bichon has skin allergies. How long can Benedryl be used in this case. Is it dangerous to give it to her indefinitely….can it harm her if taken over a prolonged time?

  • Renee

    Hi guys, I have an Aussie bulldog (sorry not a pit bull) but he is terrified in storms, so much that no matter where he is, he escapes and runs away. Due to current circumstances I am unable to have him inside in a storm, especially when they hit during the day.. what is recommend to knock him out enough so that he doesn’t climb out of his enclosure?

    • Bob Pendleton

      Get him a “Thunder Shirt.” Works wonders with fraidies .

      • Charlene Jones

        Thunder Shirt did absolutely nothing for my dog. Mine had to have tranquilizers. But that was 5 yrs ago so don’t remember name of med, was given to me by the vet.

    • Nell

      Go to your vet. & ask for Sileo. My dog is scared to the point of hiding & shivering. This comes in a syringe to give in the side of the inside of her mouth. She will calm down and or go to sleep in 15 min. It works great.

  • Ari

    I have a Chihuahua mix and last time he was weighed he was 15 pounds but I believe he is not about 20 pounds. I have been giving him half a tablet of 25mg. At first every 24 hours and now at the moment every 12 hours. He has bad environment allergies.
    Do you think I can give him an entire tablet of Benadryl every 24 hours?
    Or should I just give him half the tablet every 8 hours? Though it’s not easy as I’m away from home 7am to 5:30pm. But I can start I can give it to him tonight and then have someone give it to him on Friday when I’m not home. And then I’ll be home Saturday and Sunday.
    I plan on starting him on fish oil. And I am currently spraying spraying him with a dog itch relief tea tree. And will buy him GNC itch relief shampoo.

  • Sondra

    Gave our 4yr old 17lb yorkie bath with medicated shampoo (we never use this ) she broke out in hives pea and dime size…we have given about 5ml of children’s liquid …they haven’t gotten worse but haven’t gotten better either …any suggestions? ??

    • George Peterson

      The article above states the following: Steer clear of liquid Benadryl. In liquid form, Benadryl has high alcohol content that will be unsafe for your pet.

      • Kirk Albers

        Children’s liquid as opposed to the regular liquid,typically doesn’t have the alcohol, but certainly check the labels 1st.

  • Tricia Martin

    For those that are giving their pets Benadryl on a regular basis because of skin allergies or something of the sort, I would recommend trying to find thine source of the allergy, dryness, irritation, or whatever and treating that. Speaking from personal experience, I because allergic to antihistamine from taking it so much because of allergies. I still have allergies but now can’t take antihistamine so I have learned to find and eliminate causes as much as possible or find more natural ways to treat the symptoms. I’m not saying not to use this, but maybe sparingly is better. I’m not a vet though. Just someone with personal experience. I have been able to change the condition of my pets’ skin by changing what they eat and what I bath them with.

  • adam

    The recommended dosage makes no sense at all. If this theory was applied to humans, a two hundred pound man would take 200mg of Benadryl. It’s strange to see such advice given by professionals. Dogs 20 pounds and under should get a children benadryl at 12.5 mg. Dogs 20 – 40 pounds should get a 25 mg dosage and dogs 40 pounds and above should get 25-50 mg dosage dependent upon ailment. Most people are absent of the fact that 50 mg of Benadryl is actually used as a sleeping aid for humans. I can’t imagine any dog ever needing more than 50 mg of benadryl at one time.

  • Geoffrey Jackson

    Are topical creams safe?

  • john donald

    Interesting how allergies in Dogs has been getting more and more prevalent. Every Dog I had growing up showed no signs or symptoms of allergies. I think this has a root cause somewhere. Same with allergies in people. I don’t buy the reasoning behind a cleaner than normal environment being the cause of allergies. I would be more inclined to believe that it has a lot more to do with vaccines. Of course there is no proof, at least not in my hands, except for the fact that Dogs seem to get a lot more stuff pumped into them starting at a very young age at a time when their little immune systems are just starting to come online for lack of a better term. I’m not 100% against vaccines, I don’t really know what to think about them, but what I do think is that they may be overused and maybe even used for nefarious purposes, for instance making some people or animals not necessarily sick, but leaving them in need of a lifetime of certain treatments? I’m not saying this is certain, I’m just observing and hypothesizing.

    • TB

      Wow your dumb

    • C

      Hun, while you were growing up were you really going to realize if your dog had allergies? Most likely you or your family put it down to fleas or a dog just being a dog. Not to mention, like humans, not everyone has allergies. Saying they have become more prevalent is difficult to prove, considering the internet gives us a larger sample size than personal experience could ever have in the past. Your “observations” about vaccines, also, are based on the media and society’s fear mongering, and not on science. If you want, you can look up some scientific journals on the progression of vaccines and the active ingredients in them. It could really help clear things up if people did such instead of taking the whole “back in my day” attitude.

    • twogs

      I AGREE ITS THE OVER VACCINATIONS! After my dog has been dubbed an allergy dog ive spent MANY hours reseaching and asked many questions on different web sites. Hind site 20/20. Wishing i didnt allow all the many early in life vaccinations!

      • john donald

        I don’t like to tell people that disagree with me that I’ve got a Masters in Chemistry and currently in Medical school at the University of British Columbia. I’m not trying to tell them I’m right because I’ve got a degree, in fact I think this institution is an indoctrination mill, I’ve just got to smile and nod until I have my PhD, then I can tell people what I think as a professional. However I will tell people that do agree with what I’ve said that I have a Masters in Chem.
        Having said that I will tell you what I’ve seen in the field of science over the past 15 years. Peer review is a joke. I’ll scratch your back if you scratch mine type thing. No serious consideration of anything goes into those. Then there is research. Try obtaining a research grant to research the effects of vaccinations on people and animals. It’s just like trying to get the funds to look into alternate causes of climate change, you will not get it. If your research goes against the status-quo, or risks big oil, bit pharma, or a big corporations bottom line, you won’t get funding. A friend of mine wanted to research the effects of “Oxybenone” on people and the effect it has the oceans, lakes and rivers. No such luck. They did get private funding, but the research was largely ignored. Science has become like religion in a lot of ways, and there a lot of traditional people of science that don’t want to see it go the way of “this is the way it is because I say so” They have started calling people “Deniers” which is too bad. Nobody is denying anything, we are merely skeptical. One of the main tenets of science is scepticism. Carl Sagan said “All scientists should be skeptics. True skepticism is the self-correcting machinery of science” So of course some vaccines are necessary, but people aren’t reading my comment correctly. I did say that I believed that vaccines had “a lot to do” with allergies and that I believe that they are overused. I didn’t say they are the absolute 100% main cause of allergies, in fact I don’t believe in any absolutes except for the fact that I will die one day. Over use of anything, including drinking water, is harmful. The media will never tell you the truth behind the chemicals out there that we as humans, and now our pets are exposed to, and the eventual side effects. Did you know that processed meats are a group 1 carcinogen? Probably not, but they are, and are in the same group as tobacco and asbestos. What about Fluoride? I handle it in the lab every now and then and it says right on the container in the MSDS “do not let it come into contact with skin or eyes, toxic if ingested” I am very concentrated forms of Fluoride, but still, people will say “well they only put a little in the water” which to me is like saying, “well just a little Anthrax will be ok” I don’t care if it is put into the water in small amounts below the LD50 mark, it is poison and it’s side effects amount to cornucopia of different things. Don’t even get me started on the effects of the constant and sudden barrage of electromagnetic radiation that we are all involuntarily bathed in on a daily basis. I’m talking about wifi. This isn’t a conspiracy. Take a physics class, make it to the part on electromagnetic radiation. Actually, just go into your iphone and read the safety message. It will get to the part about how many side effects are possible if you hold the phone to close to your head for extended periods, or if you carry it in your pocket. So when it comes to vaccinations, considering the things you are not being told, and the fact that you may not understand if you were told (informed consent) maybe a little caution should be in the cards.
        Sometimes I don’t believe people can be fully informed without having obtained a degree in said field. How are you supposed to explain in 5 minutes what someone has learned in 7-10 years, it is my opinion that in some cases it can be impossible, in others, daunting to say the least.

        • john donald

          Addendum… Oxybenzone is one of the main ingredients in sunscreen.

        • Elizabeth Delaney

          Whats a good water filter or water system that doesn’t cost a arm N leg, as I’m on a fixed income.

          • Carla Bray

            I have used reversed osmosis water for all drinking and food preparation. I buy Culligan at Walmart.

        • Jodie

          Wow quite impressive. I would like to pick your brain for about 1000 hours lol. I’ve never heard the WiFi thing, but now you got me going and a little scared so I must know. Thanks.

    • rayhaneh

      even if vaccines were the root cause of this problem (which is ridiculous), I would rather my dog be itchy than die from parvo.

      • Jodi Mickay

        Research it is not ridiculous and they give more than just parvo vacs.. John has indeed shared some very wise words. Peace

    • Greg

      Thirty years ago, dogs–and humans, for that matter–didn’t subsist on daily rations of corn, soy, and omega-6 fatty acids. The chronic systemic inflammation that comes with a terrible diet has huge ramifications.

    • mrkb2366 .

      John, you are correct. We have humanized our pets. My own Vet said the dog he had never went to a Vets office. He said it also ate what the family had for their meal. The purebred animals seem to have more problems than a stray that wanders by. We have a Rottie. She has had several problems. The Veterinarian again agreed that overbred Animals immune system was compromised. He was retiring and I guess he figured it didn’t matter any longer.

  • El

    My dog has bad allergies so we gave him some Benadryl and he was fine until this morning. He can’t open one of his eyes and his breathing is ridged and heavy. Are these symptoms related to the benadryl? Is he OK?

    • George Peterson

      Sounds like a trip to the vet is in order.

  • Cassandra Fraser

    Dosage instruction here is confusing: 10 mg/ 30 lb of dog is just 1/3 mg/ lb. Elsewhere it says 1 mg per lb of dg. Which is it? That is a huge variation.

    • George Peterson

      1/3mg x 30 = 10mg = exactly what the dosage above recommended.

  • Samar

    Just so I know what to expect, can you relate your experiences with Benadryl on a 20lb or under dog? Will it make them very tired? Irritated?

  • Thepuggz

    Okay my vet legit said 25 mg of Benadryl 2-3 times a day. I have a pug and he’s about 15 lbs and he’s ten months old. I haven’t given him any yet but after hearing this 1mg per pound what kind of advice is he giving me?

  • Roc

    I have a golden retriever that gets really bad seasonal allergies, and I’ve been giving her benedryl for the past few weeks. I noticed that she still scratches quite often even though it is definitely less frequent than before. Is there a special shampoo that you recommend for dogs with itchy skin?

    • Cocoa bean

      Hi. In my experience, its also the conditioner that matters. Try a conditioning rinse with cortisone in the formula, and then try rinsing with water mixed with unfiltered Braggs apple cider vinegar… 1/3 vinegar, 2/3 water mixture. It’s really great for itchy skin. Make sure it’s the unfiltered kind. All the good stuff is in the unfiltered substance. ☺

    • cakes1998

      Sometimes it is an allergy to their food. I have a German Shepard/chow mix and she used to be able to eat a certain food and all of a sudden it was like a switch went off and she started having skin issues. No shampoos or anything helped. I switched her food to 4health (which is just as good as blue buffalo but considerably cheaper) and she hasn’t had that issue. You can get it at any tractor supply store. Well worth it.

  • krnlws66

    My dog just had a mass cell tumor removed. I was told to give him twice a day a combination of Benadryl and Pepcid. I was told the combination of this can replace Predisone (spell?) with no side effects. One day my dog was great and took only a monthly pill for heartworm and fleas and over the course of one night two lumps popped up on him and it turned out to be cancerous. I hope this medicine combination works because as badly as I hate him having to take medicine everyday I really hope he never has to go through surgery, again. He is a Great Dane turning 6 soon and since their life expectancy is short I surely don’t want him having to have a bunch of medical procedures. He is a happy boy and just loves making everyone happy.

    • Kirk Albers

      krnlws66 I’m sorry your buddy has to go through all of that. I have a 3 year old Dane myself. I am hoping you can answer a question for me regarding this article though. It says to give them 1 mg per lb but that seems a bit much. Odin is 170 lbs and 6 or 7 pills @ 25 mg ea seems like a lot. & for him I’m trying to relieve his being so itchy from flea bites. We are treating him with Fiprogaurd for the fleas, but that doesn’t help with itching.

      • brainiac 1900

        Article says 50 mg for dogs 50 lbs. or more. I have a 60 lb. dog who has suddenly developed itchy skin. I give him 25 mg every 6-8 hours. That seems to be working.

        • Jodie

          Hi. I have a Great Pyrenees and he is supposed to be up to 180 pds full grown. This is my first experience with this size of dog…he is 6 months and 65 pounds. He has itchy skin, hives before that, and I give him 25m once a day every day of Benadryl after a 3 day every 8-10 hours. Is this too much? Should I try changing his food? I don’t like the side effects, he is not his normal happy puppy self, especially in the morning walks, he is like a drunk person. Any tips for a new mom with a large breed? Thanks!!😁😁

  • Jodie

    Does anyone know about Benadryl with Great Pyrenees? He is 6 1/2 months and has a skin problem. It looked likes hives so I tried dye free Benadryl 25mg for 3 days twice a day then once a day for a week. The hives went away but he is like an old man, lethargic and will only eat if I feed it to him or sit with him while he eats, and walking him is a joke, he almost hates it now. What should I do? Call the Vet? Change his food? No more Benadryl for now. He is still chewing himself all up so not sure if the Benadryl worked at all…ugh!!

    • Jodie

      Oh to add Beau just had ALL his last puppy shots two weeks before hurricane Irma…just sayin😳

  • Becky

    Zonisamide. Benadryl

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