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PetDosageChart

Second-Generation Antihistamine (H1 Receptor Antagonist) · For Cats

How much Claritin (Loratadine) can I give my cat?

Standard Claritin dose for cats is 0.375 mg per kg (0.17 mg per lb), given Once daily. Use the calculator below for your cat's exact weight, or jump to the weight-by-weight chart.

Onset
1-3 hours
Duration
24 hours
Class
Second-Generation Antihistamine (H1 Receptor Antagonist)

Calculator estimate from Plumb’s Veterinary Drug Handbook. Not yet vet-reviewed — see our methodology .

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. Sourced from Plumb's Veterinary Drug Handbook and the Merck Veterinary Manual.

Dosage Calculator · 01

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By Weight

Claritin dose by cat weight

Pick your cat's weight to jump to a dedicated page with the dose, frequency, safety notes, and FAQ for that size.

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Dosage Chart · 02

Claritin dosage for cats by weight

Scroll sideways to see full table

Weight Low Dose Standard Max Safe 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

Common Uses · 03

What is Claritin (Loratadine) used for in cats?

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

Administration · 04

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 · 05

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 — call your vet

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

Emergency · 06

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

For Dogs

Looking for Claritin dosage for dogs?

View the Claritin dosage chart and calculator for dogs.

Related · 08

Related medications for cats

Sources · 09

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.

Read more about our methodology and how we calculate dosages.

Transparency · 11

How this page was made

Sourced from Plumb's Veterinary Drug Handbook, the reference used in US vet schools. Every dose, frequency, and tablet count on this page is generated from that data, then checked against the published references below.

Sources cited
  • Plumb's Veterinary Drug Handbook
  • Merck Veterinary Manual
Calculator formula
Doses scale linearly from a standard basis of 0.375 mg per kg (0.17 mg per lb) of body weight, given Once daily. The calculator multiplies that basis by your cat's weight and rounds to the closest available tablet size.
Last-reviewed status
Automated from Plumb’s, not yet vet-reviewed.

More on our methodology and editorial process — how we source, calculate, and review cats dosage data.

Frequently Asked · 07

Questions about this medication

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.

Safety · 10

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