Topical antiparasitic (avermectin) · For Cats

Revolution dosage reference for cats (Selamectin)

This page's standard weight-based reference is 6 mg per kg (2.72 mg per lb), with once monthly (topical application) recorded as the reference frequency. Use the calculator to see the arithmetic for your cat's weight, then confirm the indication, product, and actual dose with a veterinarian.

Onset: 12-24 hours for flea kill, full protection within 24-36 hours
Duration: 1 month
Class: Topical antiparasitic (avermectin)

Weight-based calculator estimate from the references listed on this page. This page has not been independently DVM-reviewed — see our methodology .

This information is for educational purposes only. Always consult your veterinarian before giving medication to your pet. Do not use this calculator for emergencies, overdoses, pregnancy, very young animals, very old animals, pets with liver/kidney disease, or pets taking multiple medications.

Each medication page lists the references recorded for its data. The calculator math and editorial presentation are maintained by PetDosageChart; a page is independently DVM-reviewed only when a named reviewer byline appears. See our methodology and limitations.

Selamectin (often known by brand names such as Revolution and Stronghold) is a topical antiparasitic (avermectin) commonly used in veterinary medicine for flea prevention, heartworm prevention, ear mite treatment, roundworm treatment, and hookworm treatment. Understanding the correct dosage, administration, and potential side effects of Selamectin is critical for your cat’s safety and well-being.

A typical Selamectin dose for cats is around 6 mg/kg once monthly (topical application), within a usual range of 6-12 mg/kg. Available forms include topical.

Calculator Warning: Use this only as an educational estimate. Your veterinarian may prescribe a different dose based on your pet’s condition, age, weight, other medications, and medical history.

Selamectin Dosage Calculator for Cats

Enter your cat’s weight below to estimate the Selamectin dose from the 6 mg/kg guideline. Your veterinarian may adjust it for your cat’s age, condition, and other medications, so treat the result as an educational starting point, not a prescription.

Dosage Calculator · 01

Enter your cat's weight

Quick Dosage Chart

Typical Selamectin amounts for common cat weights, for quick reference:

Dosage Chart · 02

Revolution weight-based reference chart for cats

Scroll sideways to see full table

Weight	Lower Reference	Standard Reference	Upper Reference	Frequency
3 lbs (1.4 kg)	8.4 mg	8.4 mg	16.8 mg	once monthly (topical application)
4 lbs (1.8 kg)	10.8 mg	10.8 mg	21.6 mg	once monthly (topical application)
5 lbs (2.3 kg)	13.8 mg	13.8 mg	27.6 mg	once monthly (topical application)
6 lbs (2.7 kg)	16.2 mg	16.2 mg	32.4 mg	once monthly (topical application)
7 lbs (3.2 kg)	19.2 mg	19.2 mg	38.4 mg	once monthly (topical application)
8 lbs (3.6 kg)	21.6 mg	21.6 mg	43.2 mg	once monthly (topical application)
9 lbs (4.1 kg)	24.6 mg	24.6 mg	49.2 mg	once monthly (topical application)
10 lbs (4.5 kg)	27.0 mg	27.0 mg	54.0 mg	once monthly (topical application)
12 lbs (5.4 kg)	32.4 mg	32.4 mg	64.8 mg	once monthly (topical application)
14 lbs (6.3 kg)	37.8 mg	37.8 mg	75.6 mg	once monthly (topical application)
16 lbs (7.3 kg)	43.8 mg	43.8 mg	87.6 mg	once monthly (topical application)
18 lbs (8.2 kg)	49.2 mg	49.2 mg	98.4 mg	once monthly (topical application)
20 lbs (9.1 kg)	54.6 mg	54.6 mg	109.2 mg	once monthly (topical application)
25 lbs (11.3 kg)	67.8 mg	67.8 mg	135.6 mg	once monthly (topical application)

Parenthetical tablet amounts are arithmetic comparisons only. They do not account for scoring, release type, concentration, product labeling, or whether this medication is appropriate for an individual animal.

By Weight

Revolution reference by cat weight

Choose a common weight to open its optional reference page. Use the main medication calculator for a different exact weight.

Common-weight pages are convenience views of the same educational reference, not separate medical recommendations.

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How to Give Selamectin to Your Cat

Part the fur at the base of the skull (between the shoulder blades where your cat cannot lick) and apply the entire contents of the tube directly onto the skin. Do not apply on top of the fur. Allow the area to dry completely before petting. Do not bathe your cat for at least 2 hours after application. If you have multiple cats, separate them after application until the product dries to prevent grooming each other.

It may interact with other avermectin products (ivermectin) and other topical parasite treatments.

Side Effects and Safety

Common side effects include temporary hair loss at application site, mild skin irritation, transient drooling if licked, and mild lethargy. More serious side effects can occur, such as severe skin reaction at application site, tremors or incoordination (rare), persistent vomiting, and seizures (rare, in overdose).

Cautions · 12

When Revolution should be used with caution or avoided

Some cats should not take Revolution, or need a different dose and closer monitoring. Tell your veterinarian about your pet's full health history and every other medication or supplement they take before giving Revolution.

kittens under 8 weeks old
known hypersensitivity to selamectin
severely debilitated animals
pregnancy (use with caution)

Interactions · 13

Revolution drug interactions

Revolution can interact with other drugs. This list is not complete — always give your veterinarian a full list of your cat's medications and supplements.

other avermectin products (ivermectin)

When not to use this calculator

This calculator gives a general educational estimate for a healthy adult cat at a known weight. Do not rely on it in these situations — talk to your veterinarian instead:

In an emergency, or after accidental ingestion or a suspected overdose
For pregnant or nursing pets
For very young or very old cats
For pets with liver disease, kidney disease, or another chronic illness
For pets taking several medications at once
When you are not sure of your cat's current, accurate weight
For combination products that contain additional active ingredients

Overdose · 15

Suspected overdose: what to do

If you think your cat had too much Revolution, or swallowed any medication by accident, act right away. Do not wait for symptoms to appear.

Call your veterinarian or the nearest emergency animal hospital.
ASPCA Animal Poison Control Center: (888) 426-4435
Pet Poison Helpline: (855) 764-7661

A consultation fee may apply to the poison hotlines. Have the medication packaging ready, and note how much your pet may have taken and when. Do not try to make your pet vomit unless a veterinarian tells you to.

When to Call the Vet

If your cat experiences any of the following, contact your veterinarian or an emergency clinic immediately:

Severe skin redness, swelling, or blistering at application site
Tremors, staggering, or seizures
Persistent drooling or vomiting after application
Lethargy lasting more than 24 hours
Signs of an allergic reaction (facial swelling, difficulty breathing)

Frequently Asked Questions

Frequently Asked · 07

Questions about this medication

Does Revolution protect cats against heartworm?

Yes, Revolution (selamectin) prevents heartworm disease in cats by killing the immature heartworm larvae transmitted by mosquitoes. While heartworm is less common in cats than dogs, it can be fatal with no approved treatment for adult heartworms in cats, making prevention critical — especially for cats that go outdoors or live in heartworm-endemic areas.

Can I use dog Revolution on my cat?

No, never use dog-formulated Revolution on a cat. The concentrations differ between species formulations, and using the wrong product could result in overdose or underdose. Always use the cat-specific product and the correct weight range for your cat.

How long after applying Revolution can I pet my cat?

Wait until the application site is completely dry, typically 30 minutes to 2 hours. Once dry, normal petting is fine. Avoid directly touching the application spot for the first 24 hours, and wash your hands if you do contact the wet product.

Does Revolution kill ticks on cats?

Standard Revolution (selamectin) does not reliably kill ticks. Revolution Plus (selamectin + sarolaner) was developed to add tick protection along with broader parasite coverage. If tick prevention is needed, ask your vet about Revolution Plus or other tick-specific products safe for cats.

Is Revolution safe for kittens?

Revolution is approved for kittens 8 weeks of age and older and weighing at least 2.5 lbs. It has a wide safety margin and is one of the most commonly recommended parasite preventives for young kittens. Do not use on kittens younger than 8 weeks.

Use This Guide Safely · 08

What weight alone cannot tell you

The calculator performs one narrow job: it multiplies your cat's weight by the lower, standard, and upper mg/kg values recorded for Revolution. It cannot decide whether this drug, indication, formulation, or schedule is appropriate for an individual animal.

Context in this medication record

Commonly listed uses: flea prevention, heartworm prevention, ear mite treatment, roundworm treatment, hookworm treatment
Recorded forms: topical
Reference timing: once monthly (topical application); onset 12-24 hours for flea kill, full protection within 24-36 hours; duration 1 month

Individual checks a calculator cannot perform

Confirm the diagnosis and the reason this medication is being considered.
Match the exact product, concentration, route, and whether a tablet may be split.
Account for age, pregnancy, organ function, genetics, allergies, and prior reactions.
Review every prescription, over-the-counter product, and supplement your pet takes.

Recorded cautions

kittens under 8 weeks old; known hypersensitivity to selamectin; severely debilitated animals; pregnancy (use with caution).

Recorded interactions

other avermectin products (ivermectin); other topical parasite treatments.

These lists reproduce the structured record used by this page and may not be exhaustive. Show your veterinarian the product label and your cat's complete medication list before acting on a number.

Related · 08

Related medications for cats

Sources · 09

Sources & references

The structured medication record behind this page names the references below. The links open the publisher or official resource; they do not turn this page into a prescription for an individual animal.

Plumb's Veterinary Drug Handbook — listed in this medication's source record.
Merck Veterinary Manual — listed in this medication's source record.
DailyMed label search for Selamectin — check current product and formulation labels; some veterinary uses may be off-label.

Source names are shown at the record level; passage-level page and label citations are still being added. Read our methodology and limitations.

Transparency · 11

How this page was made

This page's structured medication record includes Plumb's Veterinary Drug Handbook among its source names. PetDosageChart applies the record's mg/kg values to the entered weight and presents the arithmetic result. A source record is not the same as an individualized prescription or an independent clinical review.

Sources cited: Plumb's Veterinary Drug Handbook
Merck Veterinary Manual
Calculator formula: Doses scale linearly from a standard basis of 6 mg per kg (2.72 mg per lb) of body weight, given once monthly (topical application). The calculator multiplies that basis by your cat's weight and shows an arithmetic comparison with recorded tablet sizes. That comparison does not determine whether a tablet is scored, splittable, or appropriate for your pet.
Editorial owner: Prepared and maintained by the PetDosageChart editorial team, a software-led publisher and not a veterinary practice.
DVM review status: Not independently DVM-reviewed. A named reviewer and review date appear here only after a confirmed review.

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

Safety · 10

More resources

Pet Medication Safety Hub — What's safe, what's dangerous, and emergency signs
How we calculate dosages — Our sources, math, and review process
Printable emergency checklist — One-page reference for your fridge or first aid kit