This is not medical advice. Before pursuing feeding your dog a new food, supplement, or medication it’s advised to consult with your veterinarian.
If your dog is an adventurous soul, it’s likely they’ve rambled through poison ivy, collected a series of stinging burrs, or perhaps tried to catch a bee or wasp with their mouth. (Ouch!) Maybe your pup is the anxious sort, who would prefer that things like fireworks and thunderstorms didn’t exist. Or perhaps you’re about to travel with your dog and a helpful friend recommended you give your dog Benadryl for motion sickness and anxiety.
Learn all about Benadryl, what it can be used for, and if you can give it to your dog below!
What is Benadryl?
Benadryl is the brand name for the common medication, diphenhydramine HCL. According to the American Kennel Club (AKC), “Diphenhydramine is a first-generation ethanolamine-derivative antihistamine, which is the scientific way of classifying antihistamines that can cross the blood-brain barrier-making them very effective but also increasing the risks of adverse side effects. While Benadryl is not yet FDA-approved for veterinary use, it is considered safe for use in dogs and cats and is commonly used in veterinary practices across the U.S.”.
Benadryl can cross the blood-brain barrier that makes it both effective and potentially dangerous if used incorrectly. This is one of the reasons why it is important to talk to your vet about using Benadryl for your dog, even though it is generally safe when used appropriately.
According to the AKC, “Diphenhydramine works by blocking the receptors that receive histamines in the body.” You’re likely familiar with the term histamine if you’ve ever used over-the-counter allergy medicine, some of which contains a medicine called antihistamines. Histamines are chemicals that you and your dog’s immune system make. WebMD describes histamines “…like bouncers at a club.”. They’re made to keep the bad things out, e.g., anything from the outside that is bothering or harming your body, like allergens (pollen, mold, dust) or insect venom. Histamines are trying to get the allergen or toxic substance out of your body, or dog’s body, as quickly as possible. One of the fastest ways to eliminate toxins is through the skin. This is why we sometimes develop a rash as part of an allergic reaction. The next step after trying to get foreign substances out through the skin is through the eyes and nose, which can cause red, itchy eyes, watery eyes, and a running nose. Histamines are part of our body’s natural defense system. Sometimes though our body’s immune system can overreact, leading to allergy symptoms. Antihistamines cross through the blood-brain barrier and block receptors for histamines, meaning the body isn’t getting the signal to launch an immune response.
What does Benadryl do for dogs?
While Benadryl is generally a safe drug to give dogs when used appropriately, to do so, you must talk to your veterinarian to use it safely. Vets will often prescribe Benadryl for dogs suffering from common ailments like anxiety, allergies, and reactions to insect bites.
Benadryl is a great medication to give dogs who have mild to moderate allergy symptoms. Symptoms of allergies include hives (red, itchy bumps), swelling and inflammation, redness, runny nose and eyes, coughing, sneezing, or the very serious anaphylactic reaction. An anaphylactic reaction is a severe allergic reaction, which can sometimes be life threatening. While serious, anaphylaxis is a rare reaction.
Insect stings or bites can cause allergic reactions like swelling and inflammation, and in some cases can be dangerous or fatal. If your dog was stung or bitten by an insect or critter, try to identify the culprit by quickly searching the area for a flying or crawling insect or spider. Capture the offender, if possible, to help with appropriate treatment. If you didn’t witness your dog being stung or bitten, signs your dog was stung or bitten are if they start to suddenly paw at their face, chew a part of their body, or if some part of their body begins to swell. In case of a bee sting, look for the stinger. Bee’s leave their stinger in their victim, and the stinger continues to spread venom. If you see a stinger, use a credit card to scrape the stinger off your dog. Do not use tweezers, since squeezing the stinger will release more venom. Luckily, it’s only bees that release their stingers, other stinging insects like wasps keep their stinger with them after they sting. To soothe an insect bite, make a thick paste of water and baking soda, and apply it to the affected area. In the case of multiple stings or bites (such as if your dog explored an anthill a little too closely), give your dog an oatmeal bath. To make an oatmeal bath, grind 1/3 cup of oatmeal for small dogs, or ½ c.-1 c. oatmeal for larger breeds in a blender and add to a warm (Not hot! Hot water can dry out the skin and worsen inflammation.) bath. Next, call your vet and ask how much and what kind of Benadryl to give your dog to lessen or prevent an allergic reaction.
One of the safe side effects of Benadryl is that it is a mild sedative, which means it can make your dog relaxed and sleepy. This works well for situational anxieties due to thunderstorms, fireworks, or travel. (Benadryl also mildly prevents motion sickness, which is another reason why it could be good for dogs who are traveling.) However, when used for anxiety, sometimes Benadryl can cause the opposite reaction and make your dog even more anxious and hyper. This is one of the reasons it’s important to talk to your vet before giving your dog any medicine, even one as generally safe as Benadryl. Also, if your dog has chronic anxiety, simply giving them Benadryl will not relieve the causes of their anxiety. PetMD recommends talking to your vet about other courses of treatment which may include: changing your pet’s environment, behavioral training, medications, and other tools like dog pheromones or an anxiety vest.
What Dogs Can’t Use Benadryl?
While Benadryl is generally well tolerated, effective in dogs and has few side effects, certain dogs cannot take Benadryl safely. It is only a safe medicine for dogs when used under a veterinarian. However, there are safety risks when using Benadryl for dogs with the following conditions:
Low Blood Pressure.
Can I Give My Dog Benadryl?
After you’ve spoken to your vet about using Benadryl for your dog, the correct dosage is based on your dog’s weight. According to the Merk Veterinarian Manual, the correct dosage is 0.9 to 1.8 milligrams per pound of weight. Pet MD says this amount can be administered two to three times a day, depending on your dog’s symptoms.
While it’s best to use a Benadryl that was designed for dogs, it’s possible to use human Benadryl as well. However, there are some important things to be aware of before you give your dog Benadryl made for humans.
- Never give your dog medications with decongestants or alcohol in the formula. You want a formula with only diphenhydramine (Benadryl) because those other ingredients are toxic to dogs.
- Don’t give your dog time-released drug capsules. They could bite the capsule and receive the whole dose at once, and even if swallowed whole, time-released Benadryl could still lead to an overdose.
- For small dogs, it’s better to use children’s Benadryl, because you can adjust the dose more easily.
- Talk to your vet before giving your dog liquid Benadryl. Liquid medications are absorbed differently and need a different dosage.
Signs of an Allergic Reaction to Benadryl in Dogs
While Benadryl is generally well tolerated by dogs, occasionally some dogs have an allergic reaction. Symptoms of an allergic reaction are:
Red rash on the skin.
Swelling of the face and tongue.
Diarrhea, vomiting, and an upset stomach.
Skin chewing or licking.
If your dog is allergic to Benadryl, these signs should show up during the first hour after giving your dog the drug. Less severe side effects include sleepiness, dry mouth, rapid breathing, hypersalivation (lots of drool), and increased heart rate. However, if the severe side effects don’t go away, or if you think your dog has overdosed on Benadryl, contact your vet immediately.