Benadryl is an over the counter antihistamine for humans, which most of us have a bottle of somewhere. It is used to treat allergies and itchiness in humans and is used most commonly in dogs to treat allergies. Some vets recommend Benadryl for dogs as relief for anxiety in dogs.
What is Benadryl for dogs
As we mentioned earlier, Benadryl is an antihistamine, commonly used by humans. Antihistamines are receptor agonists or inverse agonists. They work to counter the effects of the naturally occurring chemical ‘histamine’ that is produced during an allergic reaction.
Before we give our dog any medication not prescribed specifically by his veterinarian, it’s important to make sure that we know exactly what we are doing.
Benadryl for dog allergies is the most common use of this drug. However, there are a few more ways in which Benadryl may be used by pet owners. These include treatment of the symptoms of:
- Runny eyes
- Runny nose
- Travel sickness
Benadryl for Dogs: Quick Links
Follow the links below to jump to more information about these common questions
- Uses Of Benadryl For Dogs
- Using Benadryl to treat itching
- How Does Benadryl Work?
- What Form Of Benadryl?
- Talking To Your Vet
- Benadryl Dosage For Dogs
- How Often Can I Give My Dog Benadryl?
- Side Effects Of Benadryl
- Is Benadryl Safe For Dogs?
- How To Give Your Dog Benadryl
- What are the alternatives to Benadryl?
The science behind Benadryl for dogs
Benadryl is the brand name for a product containing diphenhydramine, an antihistamine. The brand Benadryl has been around since 1946. Studies have proven its efficacy in dogs as far back as 1947. Though, it is difficult to pin down exactly whose idea it was to administer it to a dog!
The most important thing for you to know are the active ingredients. Depending on what part of the world you are in the active ingredient may differ. In the US & Canada as well as Australia and New Zealand the active ingredient is diphenhydramine. Whereas, in the UK, the active compound is either acrivastine or cetirizine.
Whatever the compound, they largely work in the same way. When you have an allergic reaction, your body processes a substance called histamine. This causes the symptoms of the allergy, like inflammation and runny eyes or nose.
Is Benadryl safe for dogs
Benadryl given in the right dose should not cause an otherwise healthy dog any serious problems. However, if your dog has an existing medical condition, it can be dangerous.
For example, you should not give Benadryl to a dog already suffering from glaucoma, high pressure, prostatic disease, hyperthyroidism or cardiovascular disease.
As with any other medication, it’s always good to have a chat with your veterinarian before you give your dog Benadryl.
Dog Benadryl toxicity
The lethal dose (LD50) for diphenhydramine in dogs ranges between 5 to 6 mg per pound of bodyweight by IV administration.
It is therefore possible for a dog to overdose and die from overconsumption of Benadryl. As few as 4 tablets of 25mg taken orally can be a lethal dose, though it may take many more in some cases.
The risk is not worth taking. Keep all medicines out of reach of curious snouts.
Using Benadryl for dogs safely
How much Benadryl is safe for a dog depends upon the dog’s weight and any pre-existing medical conditions.
For a dog in otherwise good health we calculate the dosage by weight.
1mg per pound in weight of Benadryl is the formula that is normally used. Benadryl usually comes in 25mg tablets, but you must check the packet carefully.
Can you give human Benadryl to dogs
While Benadryl is not sanctioned by the FDA for use in dogs, the literary and veterinary opinion suggests that it is safe to do so in some cases. However, it is not wise to give your dog any medication, particularly human medication without consulting with your vet.
Some varieties of Benadryl will contain other ingredients such as painkillers, expectorants (to make you cough) or decongestants, which are not appropriate for animal use. Children’s Benadryl can contain sodium too, which is not advised either.
Warning: Liquid Benadryl
You must not give your dog adult Liquid Benadryl. You can however give your dog Children’s Liquid Benadryl if your vet confirms that it is appropriate for us on them.
Liquid Children’s Benadryl usually has 12.5mg diphenhydramine in every 5ml.
This means that you can give 0.4ml of liquid children’s Benadryl per 1lb body weight.
So a 35lb dog would have a 14ml dose, for example.
Warning: UK Readers
Talking To The Veterinarian
When your dog is showing new symptoms of illness or discomfort, then your first port of call should always be to take them to the veterinarian.
Although itching can be caused by mild allergies that Benadryl can relief, they can also be signs of other problems. Potentially more serious ones too.
Do not medicate a dog yourself for a new condition without first taking him to be checked over in person. This way you can be sure he is being given an appropriate treatment.
Severe Allergic Reactions
If you think that your dog is having a severe allergic reaction, do not give him Benadryl. Don’t delay in rushing him to the vets.
Severe signs of allergy include trouble breathing, potentially with swelling of the face or neck. This can be potentially life threatening and requires immediate medical treatment from a qualified veterinarian.
Using Benadryl to treat dog itching
Itching is one of the most common signs of an allergic reaction. Benadryl, like other antihistamines excel in alleviating the discomfort of itchy skin in humans and dogs alike.
What is Itching?
Itching is symptomatic of some kind of skin irritation. This is commonly caused by an allergic reaction to contact with a foreign body or allergen.
We all know it can be difficult to resist itching a mosquito bite or a nettle sting or any number of itchy intrusions. Unfortunately, dogs suffer from the same kinds of itchiness.
It might not seem like a major problem. However if the itchiness persists, it can lead to your dog causing much more damage to himself by scratching. It may even lead to an open wound and, in turn, an infection.
Benadryl for itching in dogs
Benadryl is an effective antihistamine in dogs. Therefore, in cases where itching is caused by the release of histamine, it should prove to be somewhat useful.
If your dog’s itching persists, it’s likely that his itching is not the result of a reaction that induced a histamine response. In that case, consult your vet and she will help you deduce what the problem is.
Benadryl dosages for dogs with itchiness
Using Benadryl to treat dog anxiety
Benadryl for dogs anxiety is occasionally recommended as a temporary measure by veterinarians, as it can produce mildly sedative results.
However using Benadryl to calm dogs is not something that is a good idea on a regular basis, or as an alternative to behavioural training exercises and socialisation.
What is Anxiety?
Anxiety is just another thing humans and dogs have in common. Unfortunately our canine pals can get very stressed or anxious. Treatment of dog anxiety is quite similar to the treatments for human anxiety.
Anxiety can be treated in a number of ways, both medically using prescribed medicines and holistically/environmentally. By that I mean by making changes to your dog’s lifestyle to reduce the amount of contact he has with the things that cause him to be anxious.
Of course this isn’t always possible and medicine can be a great help to our anxious pets.
Benadryl for anxiety in dogs
Firstly, Benadryl is not the conventional choice when it comes to anxiety treatment in humans or dogs. It may be useful in the short term because it acts as a sedative. This may help your dog to get through some anxiety-inducing events.
Secondly, Benadryl is not a long term solution for anxiety in your dog. You might want to look at behavioural training and lifestyle changes as a more effective combatant.
Benadryl dosages for dogs with anxiety
If your vet recommends Benadryl for your dog’s anxiety, she will also prescribe the dosage. As a benchmark, the previous dosage of 1mg per pound of weight still applies.
Side effects of Benadryl for dogs
Remember, all remedies and medicines that have a clinical effect will also have potential side effects. Benadryl is no different.
Benadryl can have side effects, most of which are mild.
The main ingredient diphenhydramine has been known to cause drowsiness and dizziness. It can also cause stomach problems such as constipation or diarrhoea.
If your dog seems to be showing signs of an upset stomach, then speak to your vet before continuing with the next dose.
Alternatives to Benadryl for dogs
If you choose not to use Benadryl for your dog for any particular reason, you might be wondering what alternatives are available to you.
Luckily there are many solutions for dog itching and allergies. These may come in the form of dietary or medicinal products.
Benadryl benefits for dogs
Benadryl may be a useful tool to have in your box. It can come in handy if your dog is experiencing itching. It may even be useful in a pinch when it comes to any anxious episodes he might have.
However, it’s worth remembering that Benadryl is formulated for humans. As such, you need to exercise due diligence. Always read the label. Never give your dog any medication that has more than the active ingredient you require.
It’s much easier to give your vet a call before you administer any medication than it is to rush your sick pooch to the emergency room.
Giving Benadryl to your dog
If you have checked the correct dose of Benadryl, spoken to your vet and are confident that this is the right product for your dog, then you will need to think about how to give your dog a Benadryl tablet.
One way is to wrap the tablet in some tasty meat or cheese, or pop it inside a treat pouch if you have one handy.
It’s a good idea to have a second lump of meat of cheese (without a tablet in it) clearly ready and obvious to your dog when giving him the treat containing his medicine.
This makes him more eager to swallow the concealed tablet, as he will be keen to get the second treat that he can see waiting
Monitor your dog for any side effects. And contact your vet if you have any concerns
Remember! Always Check with your Vet!
The information given in this article is to supplement that provided by your vet, and in no way intended as a substitute for proper medical care for your dog.
Before you give your dog Benadryl for the first time, arrange for a vet to speak with you and give them a check up to be sure that this is the right treatment for your dog and his current problem.
Have you tried giving your dog Benadryl? We’d love to hear about your experiences in the comments below.
References and Further Reading
- Jessica Vogelsang, DVM , Can I Give My Dog Benadryl and If So, How Much?
- John P. Cunha, DO, FACOEP, Common Side Effects of Benadryl
- Australian Register of Therapeutic Goods
- Electronic Medicines Compendium, Benadryl Allergy Relief (GSL)
- T. R. Sherrod, Earl R. Loew and H. F. Schloemer, Pharmacological properties of antihistamine drugs, benadryl, pyribenzamine and neoantergan. Journal of Pharmacology and Experimental Therapeutics 1947,
- John P. Buchweitz, Stephen A. Raverty, Margaret B. Johnson, and Andreas F. Lehner Fatal diphenhydramine poisoning in a dog, The Canadian Veterinary Journal, 2014