Frontline Gold for Cats: Overview, Dosage & Side Effects

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frontline gold for cats

Frontline is a brand of topical, “spot-on” flea/tick treatment and prevention containing the main ingredient fipronil. The patent on fipronil expired in 2010, leading to the release of many generic products. Frontline has since become chiefly available as the products Frontline Plus and more recently, Frontline GOLD.

Frontline Gold for Cats Overview

Medication Type:
Phenylpyrazole antiparasitic
Topical liquid solution
Prescription Required?:
FDA Approved?:
This topical medication is approved by the EPA for use in cats.
Life Stage:
8 weeks of age or older.
Brand Names:
Fronline Gold
Common Names:
Fipronil, (s)-Methoprene, Pyriproxifen
Available Dosages:
Single dose size for cats and kittens weighing 1.5lb or more.

In this article, you’ll learn more specifically about Frontline GOLD for cats, the ingredients it contains, what types of parasitic pests it targets, possible side effects to consider, and some frequently asked questions.

If you’re looking for a broader article on all Frontline products, see our article Frontline for Cats.

About Frontline Gold for Cats

Ticked Tabby Cat

Fipronil is the primary active ingredient in all Frontline products for both dogs and cats. It is indicated for treating fleas, ticks, and chewing lice infestations. It can also kill mosquitoes. While not labeled for it, it has also been successful in treating for chiggers and the sarcoptic mange mite that causes scabies.

Fipronil is a phenylpyrazole antiparasitic agent, and is technically classified as a pesticide. In invertebrates (including insects like fleas and arachnids like ticks and mites), it interrupts GABA-regulated nerve channels, causing neurologic overexcitement, disruption and death.

Frontline “spot-on” products are applied to the surface of a small target area or “spot” of the skin, usually at the back of the head or neck.

Fipronil collects in the oils of the skin and hair, allowing for continual release, lending to its 30 day period of efficacy. Per the product label, it takes about 24 hours to spread throughout surface oils on skin and hair to provide complete protection.

It is important to note that while these pesky pests are affected by Frontline by coming in contact with the skin and don’t have to actually bite a kitty to die, Frontline products do not provide true repellency that would prevent fleas or ticks from coming in contact with a pet.

What Does Frontline Gold Do for Cats?

Frontline products are among the only topical “spot-on” options for cats providing protection against both fleas and ticks. Other products for cats may only protect against fleas and some ticks, or just fleas.

Frontline GOLD specifically includes two insect growth regulators called (S)-methoprene and pyriproxyfen, making the product more efficient at interrupting the flea life cycle by targeting flea eggs and flea larvae, eliminating flea infestations faster than other previous Frontline products.

Side Effects of Frontline Gold for Cats

Side Effects Of Frontline Gold For Cats

In most cases, when used properly, side effects to Frontline products are uncommon and the most commonly reported effect is a temporary irritation at the application site.

When used properly, side effects to Frontline products are uncommon. Frontline GOLD for cats is only labeled for cats older than 8 weeks and weighing at least 1.5 pounds. Topical products like Frontline should never be ingested.

The most commonly reported effect is a temporary irritation at the application site. More red, irritated skin has been reported, but is considered rare. If this occurs, it is more likely a kitty has a hypersensitivity or allergy to one of the ingredients.

If this occurs, the manufacturer recommends bathing with a mild soap (Dawn dish soap for example) and rinsing with lots of water. Veterinary care should be sought with any persisting or worsening signs of skin irritation.

All three ingredients found in Frontline GOLD (fipronil, (S)-methoprene, pyriproxyfen) generally appear to have a low potential for toxicity both topically and even if accidentally ingested.

However, the products are very bitter tasting. If a kitty were to lick recently applied Frontline GOLD off either themselves or a housemate, the bitter taste alone can lead to excessive drooling, agitation, and sometimes even vomiting.

According to DVM360’s article “Toxicology Brief: The 10 most common toxicoses in cats” this effect is typically not a true toxicity, but a sometimes dramatic reaction to the bitter taste. Providing milk or liquid from a tuna can help resolve the signs in short order.

To avoid this from happening, it is important to apply any topical flea/tick product to the skin in front of the shoulder blades at the back of the neck, a location even the most flexible cat cannot reach to lick. In multiple cat households where lots of co-grooming occurs, separating housemate kitties for up to 24 hours after application to allow the product to fully dry may be advisable.

Although Frontline GOLD for dogs and cats contain the same active ingredients, there are differences in the dosage of active ingredients and inactive ingredients, so the dog products should never be shared with cats.

Frontline GOLD is approved for use in breeding, pregnant, or lactating queens, but should be used cautiously in an older cat, or a cat ailing from an acute or chronic illness. Make sure to discuss with your veterinarian if any medications your cat is on may interact with a Frontline product.

If you are ever concerned that your kitty may have developed side effects while using Frontline GOLD, or any topical flea/tick medication, make sure to contact your veterinarian, the ASPCA Animal Poison Control Center (1-888-426-4435), or Pet Poison Helpline (1-855-764-7661) for further advice.

Using Caution With Other Flea/Tick Products

While Frontline GOLD for Cats has been established as a safe product, the active ingredients may be found in other products in combination with other ingredients that are not safe for cats. This is especially the case with dog products like K9 Advtantix II which contains permethrin, which is extremely toxic to cats.

Fortunately, these products are now required to include a warning against use in cats. But just to be safe, when selecting a flea/tick product for your kitty, always make sure the product includes a picture of a cat and indicates the product is specifically for cats.

It is also always advisable if you have a pup and kitty who like to hang out together or groom each other, to separate them for 24 hours after applying a topical product to your dog, especially if the product contains permethrin.

If you have any concerns for potential toxicity, even if you think your kitty might have just licked some Frontline GOLD off her fur and is having a bitter taste reaction, it is always best to contact your veterinarian, or the ASPCA Animal Poison Control Center for further advice.

And lastly, topical products like Frontline GOLD for cats have been known to cause skin and eye irritation in people. It is best to avoid contact with the solution during application and to wash your hands after.

Frontline Gold for Cats Dosage

Frontline Gold For Cats Dosage

Protection against ticks is limited to 30 days, though it provides more long-lasting protection against fleas, reportedly for up to 6 weeks according to the manufacturer.

Frontline GOLD for cats is only indicated for cats or kittens older than 8 weeks of age and weighing more than 1.5 pounds.

Frontline GOLD is typically applied every 30 days for the best flea and tick protection. Protection against ticks is limited to 30 days, though it provides more long-lasting protection against fleas, reportedly for up to 6 weeks according to the manufacturer.

Always follow all instructions on the packaging for any topical product you use for your kitty. Frontline GOLD vials have a long tip on the end. Unlike with previous Frontline products, the tip does not need to be cut or broken off. While pointing the tip away from the face, the tip is rotated clockwise ½ turn while pushing down to break the seal. It is then best applied by parting the fur and applying to the skin along the back of the neck in front of the shoulders where a kitty cannot reach to lick it off of himself.

While Frontline GOLD is considered to be waterproof, the manufacturer recommends not bathing your kitty for 48 hours after an application. Bathing shortly before application may also reduce its effectiveness.

If for some reason you are unsure if the product was administered correctly or whether all of it was applied, it is usually safest to not apply an additional dose.

If you have any questions about application or safety for Frontline products or any topical product, make sure to get in touch with your veterinarian.

Frontline Gold vs Plus for Cats

All Frontline products contain fipronil, which targets adult fleas, ticks, and lice. Frontline Plus additionally contains the insect growth regulator (S)-methoprene, which targets fleas eggs and larvae. Frontline GOLD also contains (S)-methoprene, but has a second insect growth regulator called pyriproxyfen that reduces the time it takes to start killing fleas.

Around the year 2000, Frontline Plus was released and the original Frontline started to be phased out. Frontline GOLD was released just a couple of years ago. Currently only Frontline Plus and Frontline GOLD are widely available.


Frontline GOLD is the newest incarnation of Frontline with a full month of flea and tick control. Considering more fast-acting compared to its predecessors, it has the fastest kill time against fleas and ticks.

The ingredients in Frontline GOLD are largely considered to be safe for kitties, though individual sensitivities can always occur. It’s important with any topical product to ensure it is specific for use in cats and to follow all instructions carefully.

Topical products like Frontline can all have different combinations of ingredients targeting different parasites that can sometimes be confusing. Make sure to clarify any questions you have about the best product for your kitty by having a chat with your vet.

Frequently Asked Questions

Can Frontline GOLD Be Used on Cats?

Yes, but only the cat specific product should be used. Although both the cat and dog products contain the same active ingredients, the dosages are different, especially for larger dogs, so the dog products should never be shared with cats. 

Does Frontline GOLD Have Side Effects?

Frontline GOLD is typically considered to be well-tolerated, however, side effects can occur with any topical product. Most commonly, side effects may include signs of skin irritation, like redness, itching, or other signs of discomfort at the application site. 

It’s important to remember that if your cat currently has fleas, that some of these signs may already be occurring.

Digestive upset signs including vomiting and diarrhea have also been reported. 

If you are ever concerned that your kitty may have developed side effects while using Frontline GOLD or any other topical flea/tick medication, make sure to contact your veterinarian, the ASPCA Animal Poison Control Center (1-888-426-4435), or Pet Poison Helpline (1-855-764-7661) for further advice. 

How Long Does It Take for Frontline GOLD to Work?

According to the manufacturer, Frontline GOLD can start to kill fleas within 30 minutes and can kill 100% of fleas on a pet within 12-18 hours. It is important to remember however that when first applied, it can take up to 24 hours for Frontline to be fully effective. 

When it comes to ticks, it can take up to 48 hours for them to be killed. According to the product label, mosquitoes are killed within 24 hours for up to 14 days and within 48 hours for up to 28 days.

Because the mechanism of action of Frontline products causes neurologic overexcitement of the flea prior to it dying, it is not uncommon to see “more” fleas present within the first few hours of applying the product. This may give the mistaken impression that the fleas are more active and the product is not working. However, all fleas on a pet should still be killed within 24 hours of application. 

Does frontline gold for cats kill ear mites?

Frontline Gold for Cats is not specifically labeled to kill ear mites. Consult your vet for an accurate diagnosis and use a product designed for ear mite treatment if needed.

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About Dr. Chris Vanderhoof, DVM, MPH

Dr. Chris Vanderhoof is a 2013 graduate of the Virginia-Maryland College of Veterinary Medicine (VMCVM) at Virginia Tech, where he also earned a Masters in Public Health. He completed a rotating internship with Red Bank Veterinary Hospital in New Jersey and now works as a general practitioner in the Washington D.C. area. Dr. Vanderhoof is also a copywriter specializing in the animal health field and founder of Paramount Animal Health Writing Solutions, which can be found at Dr. Vanderhoof lives in the Northern Virginia area with his family, including 3 cats.