Can I Give My Dog Zyrtec and Benadryl?

correct answerThe Short Answer is:

You need to consult your vet about the recommended dosage of Benadryl Zyrtec or Claritin for your dog based on its weight. Antihistamines all have side effects but they are usually not severe.

In this research you will know the answer to the query “Can I Give My Dog Zyrtec and Benadryl?“.

Do you notice that your dog is itching all over and scratching like crazy? Are his eyes watering? Has he been sneezing a lot lately?

It appears your pet has an allergy but what can you do to relieve his symptoms until you see a veterinarian? Is it possible to give your dog Benadryl or Zyrtec which many people already have in their medicine cabinets?

Yes allergy medications meant for humans are considered safe for pets including cats and dogs. You must however be very careful when giving Benadryl or Zyrtec to a dog. What is the proper dosage for dogs in this article? We will also discuss possible side effects and the most common allergies in dogs.

Can I give my dog Benadryl and Zyrtec at the same time?

There is very little information about the safety of taking two antihistaminic drugs at the same time but in general experts say you should not take Benadryl and Zyrtec at the same time since this may lead to stronger side effects. It refers to human consumption but since you’re using human drugs on your dog it also applies to him.

Wait until the next day to offer your dog a different drug if you feel one isnot working.

Most pet owners wonder which of the two drugs is better but its impossible to answer that question. As each dog reacts differently to them you should ask your veterinarian for recommendations if you are unsure.

How much Benadryl can I give my dog?

Diphenhydramine is an antihistamine that is used to treat allergies in dogs and humans. At the moment Benadryl is not FDA-approved for use in dogs but experts consider it to be safe nonetheless.

Animal veterinarians have been treating dog allergies with human antihistamines for years and they know how much Benadryl can be given to your suffering pet. Weight is a determining factor. 

Benadryl is recommended at a dosage of 2 – 4mg/kg or 0.9 – 1.8 milligrams per pound according to the Merck Veterinary Manual.

You should give your dog a low dose of Benadryl if this is the first time you’re giving him the medication (more on that later). For instance if you example if you have a small 10 lb dog you should give him 10 mg of Benadryl which represents 1 mg per 50 lbs dog should lb dog should take.

Find out how many milligrams are in a tablet or a liquid dose of Benadryl in your cabinet and do the math. You can safely give two 25 mg tablets to a 50 lb dog but for a small dog you will have to cut them in half. Since you can measure how many drops your dog can take with liquid Benadryl it may be easier to administer.

Dogs can be given Benadryl at regular intervals of two or three times per day. 

Whether or not you are certain your dog is having an allergic reaction you can give him some Benadryl and wait to see if the symptoms improve.

The dog might have other health issues if there is no improvement so you should take him to the vet as soon as possible.

What are the side effects of Benadryl in dogs?

To begin with you should avoid giving your dog Benadryl that contains alcohol or decongestants. For example certain formulations of Benadryl Cough Syrup and Benadryl Liquid Elixir might contain up to 14 % alcohol which is toxic to dogs. 

You should not use an alcohol-containing product if your dog suffers from seasonal allergies and needs long-term antihistamine treatment.

Tablets do not contain any alcohol so they’re usually safe.

The side effects of Benadryl are the same as those of all drugs including:

  • Drowsiness
  • Increased heartbeat
  • Rapid breathing
  • Inability to urinate
  • Dry mouth

Vomiting and diarrhea are less common side effects as a change in your dogs appetite.

Please remember that this advice is for adult dogs only. Its best to speak to a vet before administering Benadryl to a puppy pregnant or nursing dog.

How much Zyrtec can I give to my dog?

Dogs can also safely take Zyrtec which has the active ingredient cetirizine.

As per the same Merck Veterinary Manual the recommended dosage is 1 mg/kg. Therefore a 10 kg dog should receive 10 mg S

Some Zyrtec adult formulations contain 10 mg tablets so one tablet should be enough for a dog weighing 10 kg.

Taking Zyrtec no more than once or twice a day is recommended.

The same applies to Claritin the brand name for another antihistamine whose main ingredient is loratadine. The recommended dosage of Claritin is 0.2 mg/pound and can be administered once or twice a day.

The same as Benadryl Zyrtec and Claritin can cause side effects such as drowsiness and dry mouth although to a lesser extent than Benadryl.

Antihistamines should never be left within your dogs reach as he can easily chew on the plastic container and overdose. In addition to dilated pupils and rapid heart rate seizures are also common signs of antihistamine overdose. Consult your veterinarian immediately.

What are the most common allergies in dogs?

Dogs normally develop allergies after they reach the age of six months. The vast majority of dogs diagnosed with allergies are young one to two-year-olds.

In the case of dog allergies about 10% are related to food with the most prevalent allergens in this category being beef dairy products wheat eggs and various other types of meat. In the event that your dog develops an allergic reaction after you have just changed their regular food take a look at the ingredients listed on the label to determine what might be causing the reaction. Dogs can be allergic to more than one kind of food so its going to be hard to determine whats bothering them.

Similarly dogs can be allergic to a variety of things including pollen mold dust insect bites household chemicals and certain medications.

  • The trees around your house would not change so you’ll have to deal with seasonal allergies caused by pollen every spring.
  • Additionally mold spores and dust can cause allergies. It is impossible to stop dogs from poking their noses everywhere because of their inquisitive nature. When the dog sniffs under the porch he inhales mold spores and starts sneezing and itching no matter how clean the house is.
  • The term “insect proteins” is used to describe the chemicals that enter the bloodstream of your dog when it is bitten by fleas ticks and other insects. The bite site will show large bumps if your dog is allergic to insects. Dogs who are allergic to insects might scratch themselves raw if they are bitten by insects. In addition to the allergy medication check the dogs skin for signs of infection and apply an antibiotic ointment. The allergic reaction to flea saliva is called Flea Allergy Dermatitis. It causes itchiness that causes the dog to scratch himself until he removes the clumps of hair. Your veterinarian can advise you on the best way to protect your dog from fleas.
  • If your dog is allergic to vaccines you should watch him closely after his shots.
  • Despite what you might think dogs can be allergic to Benadryl although it will be pretty hard to distinguish the signs of Benadryl allergy symptoms from the allergy symptoms he was experiencing in the first place. Donot give the dog another dose if you notice any new symptoms such as seizures or difficulty breathing. Seek immediate medical attention if these occur. Acute allergic reactions are sometimes fatal.

What are the most common allergy symptoms in dogs?

Allergies are largely the same in dogs as in people. The most obvious symptom is itchiness. If you see your dog scratching and shaking his head or licking and chewing at his paws thats probably because he has an allergy.

Among other allergy symptoms are

  • Runny nose
  • Watery eyes
  • Hives
  • Swelling and inflammation
  • Coughing and sneezing

Anaphylactic shock can also occur in dogs when they experience an acute allergic reaction. Swelling in the head and throat area are the most serious signs of anaphylactic shock. The dog may stop breathing if the swelling continues. Give the dog an antihistamine you have near you immediately and then take him to the vet right away.


You can safely give your dog some of your allergy medications if he develops itchiness runny eyes or noses coughing and sneezing due to a mild allergy.

You need to consult your vet about the recommended dosage of Benadryl Zyrtec or Claritin for your dog based on its weight. Antihistamines all have side effects but they are usually not severe.

The dog might be experiencing an acute allergic reaction or anaphylactic shock if he is struggling to breathe. This is a medical emergency.

Antihistamine medications should be kept out of sight and reach of your dog preferably locked up.

If you want to read more about dog health tips read here: Dog Health Tips and Tricks.

Can I Give My Dog Zyrtec and Benadryl? (Watch Video)

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