Claritin(®) (also known as loratadine) is an antihistamine drug available over-the-counter. It can be used to treat dogs suffering from skin irritation brought on by allergies, minimize side effects from vaccinations and relieve the inflammation associated with mast cell tumors.

Which formulation should be used?

Owners should stick to using either the plain formula or children’s formula. Avoid using Claritin-D which contains the additional ingredient pseudoephedrine, as just 240 mg of pseudoephedrine could be lethal to small dogs and could cause unwanted stimulant-like effects in larger dogs. If you have accidentally given your dog Claritin-D, please contact the vet or the ASPCA pet poison hotline on (888) 426-4435 immediately.

Safer alternative:

If you’d rather avoid exposing your dog to the side effects of Claritin, use Derma-Ionx instead. Derma-Ionx is an effective natural remedy which provides fast relief from itching and skin irritation without the vomiting, diarrhea and urinary retention that’s possible when using Claritin.

Recommended Dosage

Do not give this medicine to your dog without approval from your vet.

According to Dr. Fiona, Loratadine can be given to dogs at a dosage of 0.12 mg/lb to 0.22 mg/lb (0.25 to 0.5 mg/kg) to relieve allergy symptoms. The chart below shows a typical dose of 0.2 mg/lb:

Loratadine dosage for dogs
Dog’s Weight In Pounds: Dosage In Mg:

Note that regular tablets contain 10 mg of loratadine per pill, while the children’s tablets contain 5 mg.

Example: A 20 lb dog could be given between 2.4 and 4.4 mg of loratadine. This means that half a Children’s tablet could be used (2.5 mg).

Can I Give My Dog Claritin?

Plain formulations containing loratadine as the only active ingredient can be safely given to a dog. Loratadine also appears to be safe when used in higher amounts. However, using Claritin-D which contains the ingredient pseudoephedrine could be very dangerous.

Pregnant Dogs: Because of the limited information regarding the use of loratadine during pregnancy it’s advised not to give this medicine to a pregnant dog. Instead, consider using similar medicines such as Zyrtec® which have shown to be safe for use in these circumstances.

Guidelines For Use

To ensure the safety of your dog during treatment you should always seek advice from your vet prior to use. Do not exceed the vet’s recommended dosage, and be sure to notify him or her of any medical conditions your dog suffers with, particularly liver disease. You should also tell the vet about any other medicines or supplements your pet is taking.

What Can It Treat?

In dogs Claritin is able to treat:

  • Skin irritation caused by allergies
  • Inflammation caused by mast cell tumors

It can also be used to minimize any reactions following vaccination.

Side Effects

During treatment dogs could experience these side effects:

  • Urinary retention
  • Increased thirst
  • Vomiting
  • Diarrhea

It is not expected to cause drowsiness but this side effect can still occur in rare cases or when larger amounts are used.


Large overdoses are unlikely to be lethal, but could result in several nasty side effects. If your dog has ingested an overdose get in contact with your vet as soon as possible and watch closely for drowsiness, seizures, changes in behavior, changes in body temperature and changes in the color of the gums.


Dr. Fiona
Dr. Erin