Onguard Flea & Tick Treatment for Cats & Kittens, 6 treatments (Compare to Frontline Plus), slide 1 of 1

Onguard Flea & Tick Treatment for Cats & Kittens, 6 treatments (Compare to Frontline Plus)

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Onguard Flea & Tick Treatment for Cats & Kittens is a long-lasting topical treatment that kills fleas and ticks and controls infestations of chewing lice. It works quickly to not only rid your cat of these pests, but keeps working to prevent them from coming back. This spot treatment is safe for kittens and cats that are at least 8 weeks old and 1.5 to 22 pounds. With the same active ingredients as Frontline Plus—fipronil and (S)-methoprene—Onguard keeps new flea eggs from hatching and rids your pet of adult fleas that can cause flea allergy dermatitis for up to 6 weeks. This powerful formula keeps killing Brown dog ticks, American dog ticks, Lone Star ticks and Deer ticks that may carry Lyme disease for up to a month. Application is easy—just squeeze this spot treatment onto your cat’s skin between the shoulder blades. Onguard is long-lasting and waterproof, so it still offers protection even after a bath or if your cat’s fur gets wet.

Key Benefits
  • Topical treatment kills all life stages of fleas and ticks on cats at least 8 weeks old and 1.5 to 22 pounds. Also controls infestations of chewing lice.
  • Uses fipronil and (S)-methoprene, the same active ingredients as Frontline Plus, formulated to control fleas and ticks. Effective for 30 days and safe for cats 8 weeks and older.
  • Breaks the flea life cycle and rids your cat of flea eggs, larvae, pupae and adults. Also kills tick larvae, nymphs and adults.
  • Effective against fleas that cause flea allergy dermatitis as well as Brown dog ticks, American dog ticks, Lone Star ticks and Deer ticks that may carry Lyme disease.
  • Easy to apply, long-lasting and waterproof treatment provides protection even after your cat has a bath or gets their fur wet.
What's Included

(6) applicators each containing 0.017 fl oz (0.50 ml).


Do not use on dogs. Keep out of reach of children. Use only on cats weighing over 1.5 lbs. and 8 weeks or older. It is a violation of Federal Law to use this product in a manner inconsistent with its labeling. Do not allow children to apply product. To prevent harm to you and your cat, read the entire label and package insert before each use. Follow all directions and precautionary statements carefully. Use on cats only. Do not use on dogs, rabbits or other animals.

Onguard is not manufactured by or distributed by Merial Limited. Frontline is a registered trademark of Merial Limited.

Important Information

Fleas rise to the top of your cat's coat as they die, so consider it a triumph if you start seeing more fleas at first, after treating your pet.

Onguard works to eliminate fleas in all life stages. If you’re still seeing fleas after application, it may be because your cat has picked up new fleas from the environment, which may include other pets, surfaces and outdoor areas. Don’t worry, Onguard starts working immediately on any new fleas that get on your cat, eliminating them within 24 hours from contact. It may take up to 30 days to break the entire flea life cycle. Additionally, you should also treat sources of new fleas (i.e., carpet, yard, etc.) to ensure complete flea control.

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Active Ingredients: Fipronil 9.8%, (S)-Methoprene 11.8%.


To apply Onguard Flea & Tick for Cats: Your cat needs to be dry at the time of application and remain dry for 24 hours after application. Part the hair on the neck at the base of the skull until the skin is visible.

Place the tip of the applicator on the skin and squeeze the applicator to apply the entire contents directly on the skin of your cat. Do not apply more than one applicator per treatment for one cat regardless of the cat's weight. Do not allow your cat to ingest this product, or get the product into their eyes. Proper placement of the product on your cat will minimize the opportunity for the cat to lick and ingest the product. Carefully avoid allowing the product to run off the side of the cat. Separate treated cat from all other cats and pets until product has dried.

Fleas: Kills newly emerged fleas before they lay eggs. Kills adult fleas which may cause flea allergy dermatitis.

Ticks: Kills ticks that may transmit Lyme disease. Kills tick nymphs and adults.

Lice: Rapidly controls infestations of chewing lice.

Frequency of Application

Fleas: When used monthly, Onguard Flea & Tick for Cats kills all stages of the flea life cycle and prevents reinfestation of fleas on your cat for up to six weeks after application. Although Onguard Flea & Tick for Cats can control fleas for up to six weeks, if there is a high risk of re-infestation of fleas on your cat, or if the cat has fleas which may cause flea allergy dermatitis, apply Onguard Flea & Tick for Cats once every 30 days.

Ticks: Onguard Flea & Tick for Cats kills all stages of the tick life cycle (larvae, nymph, and adult) for at least 30 days. For best control of ticks, apply once every 30 days.

Chewing Lice: Onguard Flea & Tick for Cats kills chewing lice for at least 30 days. For best control of chewing lice, apply once every 30 days.

Do not reapply Onguard Flea & Tick for Cats for 30 days.


Where is this product sourced from?

We source all our products from manufacturer approved distributors or directly from the manufacturers. Chewy takes pride in ensuring that our furry friends’ wellbeing is always our top priority. We have worked hard to partner with all of the manufactures to deliver 100% authentic products

Will I stop seeing fleas after the first application?

Onguard works to eliminate all life stages of those fleas that are already on your cat. While your cat can still get new fleas from an untreated environment, Onguard will continually eliminate any new fleas within 24 hours form contact, with uninterrupted monthly treatment. To ensure complete flea control, you must treat environmental sources of recurring flea infestations, including other pets, household surfaces and outdoor areas.

What if I still see fleas on my cat after treatment?

Seeing more fleas after treatment can be a good thing, as fleas come up to the top of your cat’s coat as they are eradicated. If your cat has had an ongoing flea infestation prior to applying Onguard, it may take up to a month to break the flea lifecycle and eliminate them entirely. Your cat can also pick up fleas from other pets, household surfaces and outdoor environments like the yard, so you must treat these other sources of flea infestations for more complete flea control.

How does Onguard protect my cat and kill fleas and ticks?

Once Onguard Flea & Tick for Cats is applied, it stores itself in the oil glands in your pet's skin. It then self-distributes continuously for one month to your pet's hair and skin through the hair follicles, killing fleas and ticks.

How often should you apply Onguard Flea & Tick for Cats?

It should be applied once per month to protect from fleas, ticks, and chewing lice.

How old does my cat need to be/or weigh to use Onguard Flea & Tick for Dogs?

Your pet should be at least 8 weeks old and at least 1.5 lbs to use this topical treatment. Please use the correct product for your pet's weight.

Can I use the same size of topical on my two cats or can I buy a larger size and split the product between my cats?

We always recommend using the proper size product for your pet. The active ingredients are in a liquid form and there would be no way to be certain that you applied the proper amount of actives for your pet. This could lead to ineffective pest control or an overdose for your pet.

How long does Onguard take to dry?

We suggest keeping your pet off of carpet and furniture for around 2 hours to allow the product to dry.

Is Onguard Flea & Tick for Cats waterproof? Does that mean pets can swim after application? Or can I bathe my cat after application?

It is recommended to wait 24-48 hours after application prior to your pet getting wet or being bathed. If this has happened the effectiveness of the product may be reduced. You can bathe your pet with a dishwashing liquid to remove any of the product that is still left, wait 24 hours and another application can be applied.

Can I use it if my pet is on medication?

Before using Onguard Flea & Tick for Cats, ask your vet about possible interactions with any medications your cat is taking.

Can I apply Onguard Flea & Tick for Cats on my dog or Onguard Flea & Tick for Dogs on my cat?

No, never apply a cat product on a dog, or a dog product on a cat; it is always recommended to apply the proper product for your pet.

I applied Onguard Flea & Tick for Cats on my cat, why am I still finding fleas?

You may still notice a small number of fleas after application as fleas rise to the top of the cat's haircoat as they die. However, if your cat had an infestation of fleas prior to application of Onguard, it may take a month or so to break the flea lifecycle and get rid of all fleas entirely. We also recommend treating your home to help avoid your cat picking up more fleas.

About Onguard Flea & Tick For Cats

Powerful protection with one easy solution

Onguard is a monthly topical spot treatment that helps eliminate fleas and ticks and protects your pet from painful bites and infestations. This flea and tick preventative not only stops ticks and fleas in their tracks, but also prevents the hatching of new fleas and keeps fighting off ticks so your cat can find relief from these pests.

Onguard Flea & Tick For Cats
Preventing Fleas at Every Turn

Fleas are not only a nuisance to your kitty, but they may also cause bigger problems like flea allergy dermatitis. The best way to prevent and eliminate a flea problem is to attack them at all life stages, which Onguard does efficiently.

Flea finds a home

Flea finds a home

Once on your cat, it bites to feed within just 2 hours.

Eggs are laid

Eggs are laid

In 2 days, an adult flea will lay eggs.

Eggs hatch into larvae

Eggs hatch into larvae

Eggs fall off your pet, scatter around the home, and then hatch.

Larvae turn into pupae

Larvae turn into pupae

Pupae can wait for up to a year before emerging as adult fleas.

2 Powerful Active Ingredients

Onguard uses two active ingredients that are commonly used to protect cats from fleas and ticks. Fipronil and (S)-methoprene work together to stop an infestation in its tracks and prevent future ones. Fipronil kills adult fleas, ticks and chewing lice. (S)-methoprene prevents reinfestation by eliminating flea eggs and larvae by disrupting their maturation. Together the two create a highly effective flea and tick preventative.

One-Step Application

These topical flea and tick treatments are easy to apply and effective for up to 30 days. Each box contains six applications so you can keep your pet protected for a full six months. Simply apply it between the shoulder blades of your pet, and the long-lasting solution will keep protecting them from fleas and ticks. The formula is both waterproof and sunlight-proof, so you don't have to worry about reapplication throughout the month.

Combating Ticks for a Healthier Pet

Onguard is an effective preventative that kills ticks at all life stages and keeps them from coming back. Monthly applications of Onguard can protect your pet from ticks that may carry Lyme disease and Rocky Mountain spotted fever. It kills many of the most common types of ticks that carry these diseases.

Effective preventative that kills ticks
About Halo

Onguard is dedicated to protecting cats and dogs from the discomfort and diseases that come along with flea and tick infestations. That is why they offer efficient and effective flea and tick treatments that will keep your pet happy and healthy. Their monthly solutions for flea and tick prevention are convenient and ideal for busy pet parents who want to spend more time with their pets, not fighting off fleas and ticks.

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