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PetDosageChart

Claritin (Loratadine) Dosage for Cats

Second-Generation Antihistamine (H1 Receptor Antagonist) ⏱ Onset: 1-3 hours ⏳ Duration: 24 hours

This dosage information is for educational purposes only. Always consult your veterinarian before giving any medication to your pet. Dosages may vary based on your pet's health conditions, other medications, and individual factors.

Content reviewed by licensed veterinarians. This information is sourced from veterinary drug references including Plumb's Veterinary Drug Handbook and the Merck Veterinary Manual.

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Claritin Dosage Chart for Cats by Weight

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Weight Low Dose Standard Dose Max Dose Frequency
3 lbs (1.4 kg) 0.5mg 0.5mg 0.5mg Once daily
4 lbs (1.8 kg) 0.5mg 0.5mg 1mg Once daily
5 lbs (2.3 kg) 0.5mg 1mg 1mg Once daily
6 lbs (2.7 kg) 0.5mg 1mg 1.5mg Once daily
7 lbs (3.2 kg) 1mg 1mg 1.5mg Once daily
8 lbs (3.6 kg) 1mg 1.5mg 2mg Once daily
9 lbs (4.1 kg) 1mg 1.5mg 2mg Once daily
10 lbs (4.5 kg) 1mg 1.5mg 2.5mg Once daily
12 lbs (5.4 kg) 1.5mg 2mg 2.5mg Once daily
14 lbs (6.3 kg) 1.5mg 2.5mg 3mg Once daily
16 lbs (7.3 kg) 2mg 2.5mg 3.5mg Once daily
18 lbs (8.2 kg) 2mg 3mg 4mg (5mg tablet) Once daily
20 lbs (9.1 kg) 2.5mg 3.5mg 4.5mg (5mg tablet) Once daily
25 lbs (11.3 kg) 3mg 4mg (5mg tablet) 5.5mg (5mg tablet) Once daily

What is Claritin (Loratadine) used for in cats?

Allergic dermatitis Environmental allergies (atopy) Itching and scratching Allergic rhinitis

How to give Claritin to your cat

Loratadine tablets can be cut to the appropriate dose and hidden in a pill pocket or small piece of soft treat. Because cat doses are small fractions of human tablets, precise cutting is important—a pill cutter helps. Alternatively, use the children's liquid suspension (1 mg/mL) measured with an oral syringe for accurate dosing. The liquid can be mixed into a small amount of wet food. Loratadine can be given with or without food. Always verify the product is plain loratadine—NEVER Claritin-D.

Available Forms

Tablet, Oral syrup

Give with Food?

No — can be given without food

Side effects of Claritin in cats

Common side effects

Mild sedation (less than first-generation antihistamines)
Dry mouth
Decreased appetite
Gastrointestinal upset

Serious side effects

  • Urinary retention
  • Rapid heart rate (tachycardia)
  • Severe allergic reaction to the medication
  • Liver dysfunction (rare)

When to call the vet

Call your vet immediately if your cat shows any of these signs:

  • Rapid heart rate or panting
  • Difficulty urinating or straining in the litter box
  • Signs of allergic reaction: facial swelling, hives, vomiting
  • Extreme lethargy or disorientation
  • No improvement in allergy symptoms after 2 weeks of daily use

Related Medications for Cats

Second-Generation Antihistamine (H1 Receptor Antagonist)

Zyrtec

Cetirizine

For Allergic dermatitis and itching

View dosage chart
Antihistamine (H1 Receptor Antagonist)

Atarax

Hydroxyzine

For Allergic dermatitis and itching

View dosage chart
NK1 receptor antagonist / Antiemetic

Cerenia

Maropitant

For vomiting

View dosage chart
H2 receptor antagonist

Pepcid

Famotidine

For stomach acid reduction

View dosage chart

Sources & References

The dosage information on this page is compiled from the following veterinary and pharmaceutical references:

  • Plumb's Veterinary Drug Handbook — the standard veterinary pharmacology reference used by veterinarians worldwide.
  • Merck Veterinary Manual — a trusted, peer-reviewed resource for veterinary professionals and pet owners.
  • DailyMed (FDA Drug Labels) — official FDA-approved drug labeling and prescribing information for Loratadine.

Frequently Asked Questions

Can I give my cat Claritin for allergies?
Plain loratadine (Claritin) can be given to cats for allergy symptoms at a dose of 0.25-0.5 mg/kg once daily. For an average 4 kg cat, this is about 1-2 mg per day. CRITICAL WARNING: Never use Claritin-D, which contains pseudoephedrine—a decongestant that is toxic and potentially fatal to cats. Always check the label to ensure it is plain loratadine only.
Is Claritin less sedating than Benadryl for cats?
Yes, loratadine (Claritin) is a second-generation antihistamine that causes significantly less sedation than diphenhydramine (Benadryl), which is a first-generation antihistamine. This makes Claritin a better choice for cats that become overly drowsy on Benadryl or need daily allergy management without sedation. However, some cats may still experience mild drowsiness.
How do I dose Claritin for a small cat?
For small cats (3-4 kg), the dose is approximately 0.75-2 mg of loratadine per day. Since Claritin tablets come in 5 mg and 10 mg sizes, you will likely need to cut the tablet. A quarter of a 5 mg tablet (1.25 mg) is a common starting dose for an average-sized cat. The children's liquid formulation can make measuring small doses easier—but check that it does not contain xylitol or pseudoephedrine.
How long does it take for Claritin to work in cats?
Loratadine typically begins working within 1-3 hours in cats. For chronic allergies, the full benefit may take several days of consistent daily dosing to become apparent. Antihistamines are generally more effective when given preventatively before allergen exposure rather than after itching has already started.
Can I use Claritin liquid for my cat?
Yes, the children's liquid formulation of loratadine can be easier to dose for cats. Ensure the product contains ONLY loratadine as the active ingredient—no pseudoephedrine (Claritin-D) and no xylitol sweetener (toxic to some animals). The standard children's liquid is 1 mg/mL, making it relatively easy to measure small cat-appropriate doses with a syringe.

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