Introduction
Both Zyrtec (cetirizine) and Benadryl (diphenhydramine) are antihistamines commonly used to treat allergies in humans and pets. Antihistamines work by blocking the effects of histamine, a chemical released by the body during an allergic reaction. Histamine is responsible for many of the bothersome symptoms associated with allergies, such as itching, sneezing, and runny nose or eyes. By blocking histamine, antihistamines can provide relief for dogs experiencing allergic reactions.
Benadryl for Dogs
Benadryl is a commonly used over-the-counter antihistamine that veterinarians prescribe for dogs with mild to moderate allergies or travel anxiety. The active ingredient in Benadryl is diphenhydramine which blocks histamines that cause allergy symptoms and drowsiness
Some common uses of Benadryl in dogs include:
- Relieving symptoms of seasonal, environmental, or food allergies like itching, sneezing, and watery eyes
- Treating insect bites and stings
- Alleviating motion sickness during travel
- Reducing anxiety during vet visits, grooming, thunderstorms or fireworks
The recommended Benadryl dosage for dogs is 1 mg per pound of body weight, given 2-3 times a day. For a 25 pound dog, a 25 mg dosage is appropriate. Some side effects like drowsiness, dry mouth, and lack of coordination can occur. It’s important to consult your vet before administering (Benadryl For Dogs – American Kennel Club).
Zyrtec for Dogs
Zyrtec (cetirizine) is an over-the-counter antihistamine sometimes prescribed by veterinarians for dogs with allergies or atopic dermatitis. It works by blocking histamine receptors and reducing inflammation associated with allergic reactions (source).
Common uses of Zyrtec in dogs include treating itchy skin, hives, and respiratory allergies. The standard dosage is 1 mg per pound given once or twice daily (source). Zyrtec begins working within 1-2 hours and lasts for 24 hours.
Potential side effects of Zyrtec are mild but may include vomiting, diarrhea, loss of appetite, lethargy, and restlessness. Most dogs tolerate Zyrtec well, especially at the recommended dosage. It’s important to give the medication with food and follow label instructions closely.
Overall, vets often recommend Zyrtec as an accessible OTC option for managing dog allergies. It provides relief from allergy symptoms without as many potential side effects as some prescription medications.
Comparing Benadryl and Zyrtec
Both Benadryl and Zyrtec are common over-the-counter antihistamines used to treat allergies and itchiness in dogs. However, there are some key differences between the two medications:
Benadryl contains the active ingredient diphenhydramine, which is a first-generation antihistamine that works by blocking the effects of histamine in the body. This helps reduce symptoms like itching, sneezing, and runny nose or eyes (Kingsdale).
Zyrtec contains the active ingredient cetirizine, which is a second-generation antihistamine. It is more selective in the receptors it targets, so it has fewer side effects like drowsiness. Studies in dogs have found cetirizine to be more effective at preventing allergic reactions compared to diphenhydramine (Banovic et al.).
Benadryl typically starts working within 30 minutes, while Zyrtec can take 1-2 hours to take effect. However, Zyrtec provides relief for a full 24 hours, while Benadryl may only last 4-6 hours (Wagwalking). So Zyrtec may need to be given less frequently.
Benefits of Using Zyrtec
One of the main benefits of using Zyrtec over Benadryl for dogs is that it has a longer lasting effect. While Benadryl typically provides relief for 4-6 hours, Zyrtec can last for 24 hours or more. This means you may only need to give your dog Zyrtec once a day, compared to multiple doses of Benadryl per day.
Zyrtec also causes much less sedation than Benadryl. Benadryl is known for making dogs very sleepy and lethargic. Zyrtec has minimal effects on sedation, so it won’t affect your dog’s energy levels or make them drowsy. Your dog should be able to function normally while taking Zyrtec.
The longer lasting effects and decreased sedation are two of the major advantages of using Zyrtec rather than Benadryl for dogs with allergies or itchy skin. You can provide 24 hours of relief for your pup without making them overly sleepy.
Drawbacks of Using Zyrtec
While Zyrtec can be an effective allergy medication for dogs, there are some potential drawbacks to be aware of compared to using Benadryl:
Zyrtec requires a prescription from a veterinarian, whereas Benadryl can be purchased over-the-counter. This means an extra vet visit is needed to obtain Zyrtec, which can be inconvenient and costly for dog owners.
Zyrtec is also more expensive than Benadryl. A month’s supply of generic cetirizine (Zyrtec) can cost $15-30, while a bottle of Benadryl is typically just a few dollars. For owners with multiple dogs or limited budgets, the price difference may make Benadryl the more practical option.
However, for dogs that don’t respond well to Benadryl or need a daily allergy medication, the advantages of using Zyrtec may outweigh the drawbacks of cost and accessibility for many owners. Discussing the pros and cons of each medication with your vet can help determine if Zyrtec is the right choice for your dog’s allergy symptoms.
When to Use Each Medication
Benadryl and Zyrtec are both antihistamines that can help relieve allergy symptoms in dogs, but they have some differences in their recommended uses:
Benadryl is often used for acute allergic reactions like insect bites or stings, vaccine reactions, or contact allergies. Its effects come on quickly, so it can provide fast relief when needed [1]. Benadryl is also frequently used as a mild sedative for dogs before car rides, vet visits, grooming, or other stressful situations.
Zyrtec is more commonly used for chronic allergy issues like seasonal environmental allergies or food allergies that cause ongoing itchy skin. It takes a bit longer to start working than Benadryl, but provides longer lasting relief. Zyrtec can be given daily to help control persistent allergy symptoms [2].
In general, vets recommend Benadryl for fast-acting, short-term allergy relief and Zyrtec for daily maintenance and control of chronic allergies. Either medication can provide symptomatic relief, so talk to your vet about the best antihistamine for your dog’s specific needs.
Getting a Prescription
In order for your vet to prescribe Zyrtec for your dog, they will need to examine your dog first to determine if Zyrtec is appropriate. Some key points about getting a Zyrtec prescription for your dog:
- Make an appointment with your veterinarian for an examination. Discuss your dog’s symptoms and why you think Zyrtec may help.
- The vet will evaluate your dog’s medical history and conduct a physical exam. They may recommend blood work or other tests to rule out other conditions.
- If allergy symptoms are present and the vet believes Zyrtec is a good treatment option, they will provide a prescription for the medication.
- Prescriptions allow you to obtain Zyrtec at much lower dosages than what is available over-the-counter for humans.
- Dosage will be determined based on your dog’s weight. Follow your vet’s instructions closely.
- You can fill the Zyrtec prescription at your local pharmacy. Compound pharmacies can create lower dosage versions if needed.
Always consult with your vet before giving any new medication to your dog. Let them examine your pet and determine if Zyrtec is suitable. With a prescription, you can access safe, effective dosages of Zyrtec specifically calibrated for your dog.
Dosage and Administration
When giving Zyrtec to your dog, it’s important to administer the proper dose based on your dog’s weight. Zyrtec dosage for dogs is typically 0.9-1.8 mg per pound, given once or twice daily.
For small dogs under 10 pounds, a typical dose is 2.5 mg. This would be half of a 5 mg tablet or a quarter of a 10 mg tablet. For medium dogs between 10-50 pounds, the dose is often one 10 mg tablet. For large dogs over 50 pounds, the dose can be two 10 mg tablets.
Zyrtec comes in both tablet and liquid forms. Tablets can be hidden in food. For the liquid, carefully measure out the dose using an oral syringe or dosing cup. Give liquid Zyrtec directly into your dog’s mouth or mixed with a small amount of wet food.
When first starting Zyrtec, begin with a low dose and gradually increase over 2-3 days to the full recommended amount. This allows your dog’s system to adjust. Zyrtec reaches full effectiveness at 1-2 weeks. Do not exceed the maximum dosage appropriate for your dog’s weight.
Always follow your veterinarian’s dosage instructions. Check with your vet before giving Zyrtec to pregnant dogs or dogs on other medications. Monitor your dog after administering Zyrtec to watch for any side effects.
Conclusion
In summary, both Benadryl and Zyrtec can be used to treat allergies and allergic reactions in dogs, but they have some key differences. Zyrtec tends to last longer and is less likely to cause drowsiness compared to Benadryl. However, Benadryl starts working faster and may be preferable for acute allergic reactions. It’s best to consult your veterinarian before giving either medication, as the dosage must be adjusted based on your dog’s weight. Your vet can help you determine which one is right for your dog’s specific needs and symptoms.
The bottom line is that both Benadryl and Zyrtec can provide allergy relief for dogs, but Zyrtec may be the better choice for long-term management if drowsiness is a concern. Always follow your vet’s dosage recommendations carefully when giving any medication to your dog. With appropriate use under veterinary guidance, both of these OTC antihistamines can be safe and effective options for managing canine allergies.