Cetirizine (Zyrtec® or Reactine®) is one of the most commonly used over-the-counter antihistamines recommended by veterinarians. Claritin® can be used but is not typically recommended by veterinarians as some forms of Claritin® contain decongestants such as pseudoephedrine which is very toxic to dogs.
Zyrtec is an over-the-counter human allergy medication sometimes given to dogs with atopic dermatitis or mild to moderate environmental allergies. Vets may recommend Zyrtec for dogs who scratch excessively, are sensitive to insect bites, or have dermatitis.
Zyrtec Dosage and Instructions. It is recommended to give your dog 0.5mg per pound of body weight. You can safely give Zyrtec to your dog up to 20 mg per day.
Zyrtec (cetirizine) or Claritin (loratadine) can be given once to twice daily. The adult tablets are both 10mg. Dogs under 10 pounds should get no more than 5mg, or ½ of a tablet. Those weighing 10-50 pounds should get 10mg, and heavy dogs (over 50 pounds) can take up to 20mg.
Antihistamines with the active ingredients of diphenhydramine, chlorpheniramine, cetirizine, clemastine or loratadine are usually safe for most healthy adult dogs. Hydroxyzine is another dog-safe antihistamine and one of the most effective available, but it's only available on prescription.
DO NOT USE ALLEGRA D IN PETS. Fexofenadine is also available an oral suspension that contains xylitol (NOTE: Xylitol may be toxic in dogs). The human oral suspension is not recommended for use in pets.
The dose is 1 mg/kg twice daily. fexofenadine (Telfast®) – this is a second gen. It is available as 60 mg capsules and 120 or 180 mg tablets. The dose is 5–10 mg/kg once or twice daily (don't use if your dog is on ketoconazole or a macrolide antibiotic)
Claritin is used to treat symptoms like runny noses and hives in humans, but it is primarily used to address itchy skin in dogs. It is not, however, appropriate for emergency use, such as during a life-threatening allergic reaction.
Bottom Line. Zyrtec and Claritin are both second generation antihistamines with low risk of sedation; however, Zyrtec is more likely to cause sedation than Claritin. Zyrtec also has a quicker onset of action (one hour vs up to three hours for Claritin) but both last for 24 hours.
Recommended Claritin Dosage For Dogs
The recommended dose for Claritin is 0.2 milligrams per pound of body weight every 12-24 hours. This is only a general recommendation, and as with all medication, you should consult with your veterinarian and have them give you the appropriate dose for your individual dog.
Cetirizine (Zyrtec® or Reactine®) dose: The typical dose is 1 mg/kg every 24 hours. Hydroxyzine (Vistaril®) dose: The typical dose is 2-4 mg/kg every 8-12 hours.
Cetirizine (Zyrtec®, Reactine®) is an antihistamine used to treat and prevent pruritus (itching) associated with atopic dermatitis, urticaria (hives), and insect bite reactions in cats and dogs.
Diphenhydramine (Benadryl): 1mg per pound (one 25mg tablet for a 25lb dog) twice daily. Cetirizine (Zyrtec) ¼ - ½ mg per pound (one 10mg tab per 30-40 lbs) twice daily.
Benadryl is a great medication for use in dogs with mild-to-moderate allergies. Seasonal allergies, food allergies, environmental allergies, and allergic reactions to snake and insect bites all respond to Benadryl in most cases.
ZYRTEC 10 mg film-coated tablets
Swallow the tablet whole, with a glass of water. You can divide the tablet into two equal doses.
Diphenhydramine (Benadryl®), cetirizine (Zyrtec®), and loratadine (Claritin®) are commonly used antihistamines that relieve allergy symptoms or counteract allergic reactions. Antihistamines are usually safe but can make some dogs drowsy and others hyperactive.
“Zyrtec is found to be more potent, or stronger, in laboratory studies, compared with Claritin,” says Dr. Kung. “It also reaches a higher concentration in the skin, which can be more helpful for skin-related allergies. However, Zyrtec has a greater chance of making you sleepy while taking it.”
Zyrtec (cetirizine) and Claritin (loratidine) are two popular brands. They contain different compounds but appear to be equally effective. Antihistamines can reduce allergy symptoms, such as watering eyes, itchy skin, hives, and swelling.
Other safe antihistamines for dogs include Claritin (loratadine) and Zyrtec (cetirizine). They produce less sedation than Benadryl does but could still make your dog drowsy. Warning: Make sure your OTC allergy medicine only contains antihistamines.
These include Claritin, Zyrtec, and Benadryl. Benadryl may be more commonly used but can also produce more drowsiness than Claritin or Zyrtec. How long does it take for Claritin to work on dogs? If your dog is suffering from allergies, your dog should show improvement one to two hours after taking Claritin.
Telfast®- (active ingredient fexofenadine ) these are available in 60 to 180 mg tabs. But note that while not likely to overdose, the dosage for most dogs is only 5-10 mg / Kg once or twice a day.
Toxicity to pets
When accidentally ingested by dogs and cats, antihistamine poisoning can result in clinical signs of severe agitation, lethargy, sedation, aggression, abnormal heart rate, abnormal blood pressure, vomiting, diarrhea, inappetance, seizures, respiratory depression, and even death.
Can I give Human Painkillers to my Pet? The short answer is NO. You should never attempt to treat your pets with human medication, precautions should be taken to keep household medications out reach of your pet to avoid a potentially harmful or fatal reaction.
Vets generally prescribe Claritin for dogs in a dosage 0.2 milligrams per pound of body weight. This can translate as giving a small dog around 5 milligrams of Claritin every day, or 10 milligrams for a larger dog.