Frontline is a topical flea and tick preventative that is applied to your dog’s skin. It is used to protect your pet from fleas and ticks, as well as other parasites including ear mites, sarcoptic mange and more.
Fleas are external parasites that feed on the blood of dogs, cats, birds and other animals. Fleas can cause severe irritation to your pet’s skin and can even lead to anemia if left untreated. Fleas have been known to transmit diseases from one animal to another, so it’s important to get rid of these pests before they have the chance to spread any diseases.
Frontline kills fleas on your dog immediately after application. It does not work instantly, but fleas will die within 12 hours of application. If you see fleas on your dog, it’s likely that they were recently laid by the adult female flea and are not yet ready to lay eggs. You should still apply Frontline if you see any signs of fleas on your dog because they will continue to bite and cause discomfort for your pet.
Does Frontline Treat Existing Fleas?
Yes, Frontline can treat existing fleas. It is a topical medication, so it is applied to the skin of your cat or dog. The medication works by entering the bloodstream and killing adult fleas on contact. It takes about 24 hours for the drug to start working.
In order to kill the existing fleas on your dog, you should apply Frontline according to the directions on the package. The product will kill adult fleas within 24 hours and prevent further infestation for up to three months.
How Long Does It Take Frontline to Start Killing Fleas on Dogs?
Frontline Plus takes about 24 hours to start killing fleas, but it can take several days for you to see the full effect.
If you’re using Frontline Plus on your dog and you notice any fleas, don’t panic. It’s normal for fleas to be around for a few days after administering the medication. This is because Frontline Plus works by preventing new flea eggs from hatching and by killing adult fleas that bite your pet.
Why Are Fleas Still Alive After Frontline?
Fleas can be tricky little bloodsuckers.
While it’s true that Frontline Plus will kill adult fleas, it’s important to remember that the product only kills adult fleas—it doesn’t kill eggs or larvae. This means that while Frontline Plus is working to kill the ones you see, you’ll still have to be vigilant and continue treating your pet with other products, like flea shampoo or collars, in order to get rid of all of them.
The longer it takes for you and your pets to notice a flea infestation, the harder it will be to get rid of them completely. If you notice any signs of fleas (e.g., itching), try using a product like Advantage II monthly for three months in addition to your regular treatment routine.
How Do You Know When Fleas Are Dying?
The best way to tell if a flea is dying is to look at its body. If you have a magnifying glass, you can examine the flea’s body for signs of distress.
Fleas are tiny, but they are quite distinct in their appearance. They look like little brownish-black bugs with six legs and a long tail. The adult flea has two sets of compound eyes and two pairs of wings. A female adult flea is larger than a male adult flea, but both adults are about the same size as an ant.
When you look at a live flea through your magnifying glass, it will appear to be moving around normally. However, when you see dead or dying fleas on the floor or in your pet’s fur, these insects will appear sluggish and may be unable to move at all. Their bodies may be bent over or arched backwards so that their heads are up against their back ends (this posture is called “couching”). The shape of their bodies may also change slightly as they die; they may become more elongated or flattened as well.
List of Frontline Product and Where to Buy
Frontline is a product that helps stop fleas and ticks from attacking your dog. It’s an easy-to-use, topical treatment that protects your dog for up to three months.

FRONTLINE Plus for Cats and Kittens (1.5 pounds and over) Flea and Tick Treatment, 3 Doses
Price : $38.99
Features :
- Waterproof flea and tick treatment for cats and kittens: Frontline Plus for Cats provides waterproof, fast-acting, long-lasting flea and tick treatment and control for your cat. This product is approved for use on cats and kittens 1.5 lbs and over.
- Break the flea life cycle with frontline: Frontline flea and tick treatment for cats kills adult fleas plus flea eggs and larvae to stop existing infestations and prevent establishment of new infestations.
- Kills fleas and ticks: Frontline flea and tick treatment for cats kills fleas, flea eggs, lice, and ticks. This flea and tick treatment kills ticks, including those that may transmit Lyme disease.
- Trusted flea and tick protection for cats: Frontline Plus for Cats has been trusted by veterinarians for nearly 20 years. Made with 2 tough killing ingredients, fipronil and (S)-methoprene – one to kill adult fleas and ticks and the second to kill flea eggs and larvae – this fast-acting, long-lasting protection provides flea and tick control for cats and kittens 8 weeks and older.
- Lasting flea and tick protection: Frontline’s long-lasting formula is stored in the oil glands of the cat’s skin to give non-stop flea and tick protection for a full 30 days. Frontline flea and tick treatment for cats works non-stop for a full 30 days. A 3-dose supply lasts for 3 months.
Additional Info :
Color | Green |
Item Dimensions | |
Height | 0.5 Inches |
Width | 4.5 Inches |
Length | 6 Inches |
Weight | 0.07054792384 Pounds |

Purina FortiFlora Probiotics for Dogs, Pro Plan Veterinary Supplements Powder Probiotic Dog Supplement – 30 ct. box
Price : $30.99
Features :
- One (1) 30-Count Box – Purina Pro Plan Veterinary Diets Probiotics Dog Supplement, Fortiflora Canine Nutritional Supplement
- Probiotic recommended by veterinarians (Kynetec, Probiotic Recommendation Study, March 2019)
- A Probiotic supplement for the dietary management of puppies and adult dogs with diarrhea
- Contains a probiotic to promote normal intestinal microflora. Helps reduce flatulence
- Proprietary microencapsulation process for enhanced stability
Additional Info :
Item Dimensions | |
Height | 3.25 Inches |
Width | 2.25 Inches |
Length | 3 Inches |
Weight | 0.06625 Pounds |

Frontline Plus Flea and Tick Treatment for Dogs (Small Dog, 5-22 Pounds, 3 Doses)
Price : $38.99
Features :
- Waterproof flea and tick treatment for dogs: Frontline Plus for Dogs provides waterproof, fast-acting, long-lasting flea and tick treatment and control for your dog. This product is approved for use on dogs 5-22 lbs.
- Break the flea life cycle with frontline: Frontline flea and tick treatment for dogs kills adult fleas plus flea eggs and larvae to stop existing infestations and prevent establishment of new infestations.
- Kills fleas and ticks: Frontline flea and tick treatment for dogs kills fleas, flea eggs, lice, and ticks. This flea and tick treatment kills ticks, including those that may transmit Lyme disease.
- Trusted flea and tick protection for dogs: Frontline has been trusted by veterinarians for nearly 20 years. Made with 2 tough killing ingredients, fipronil and (S)-methoprene – one to kill adult fleas and ticks and the second to kill flea eggs and larvae – this fast-acting, long-lasting protection provides flea and tick control for dogs and puppies 8 weeks and older
- Lasting flea and tick protection: Frontline’s long-lasting formula isstored in the oil glands of the pet’s skin to give non-stop flea and tick protection for a full 30 days. Frontline flea and tick treatment for dogs works non-stop for a full 30 days. A 3-dose supply lasts for 3 months.
Additional Info :
Color | orange |
Item Dimensions | |
Height | 4.5 Inches |
Width | 0.75 Inches |
Length | 5.75 Inches |
Weight | 0.8 Pounds |

Frontline Plus Flea and Tick Treatment for Dogs (Medium Dog, 23-44 Pounds, 3 Doses)
Price : $38.99
Features :
- Waterproof flea and tick treatment for dogs: Frontline Plus for Dogs provides waterproof, fast-acting, long-lasting flea and tick treatment and control for your dog. This product is approved for use on dogs 23-44 lbs.
- Break the flea life cycle with frontline: Frontline flea and tick treatment for dogs kills adult fleas plus flea eggs and larvae to stop existing infestations and prevent establishment of new infestations.
- Kills fleas and ticks: Frontline flea and tick treatment for dogs kills fleas, flea eggs, lice, and ticks. This flea and tick treatment kills ticks, including those that may transmit Lyme disease.
- Trusted flea and tick protection for dogs: Frontline has been trusted by veterinarians for nearly 20 years. Made with 2 tough killing ingredients, fipronil and (S)-methoprene – one to kill adult fleas and ticks and the second to kill flea eggs and larvae – this fast-acting, long-lasting protection provides flea and tick control for dogs and puppies 8 weeks and older
- Lasting flea and tick protection: Frontline’s long-lasting formula isstored in the oil glands of the pet’s skin to give non-stop flea and tick protection for a full 30 days. Frontline flea and tick treatment for dogs works non-stop for a full 30 days. A 3-dose supply lasts for 3 months.
Additional Info :
Color | Blacks & Grays |
Item Dimensions | |
Height | 4.5 Inches |
Width | 0.75 Inches |
Length | 5.75 Inches |
Weight | 0.0625 Pounds |

FRONTLINE Dog Spray 500mL
Price : $55.99
Features :
- Contains fipronil to kill existing flea and tick infestations. It also kills fleas before they lay eggs, effectively preventing reinfestation for up to 30 days
- Kills up to 100% of existing fleas within 24 hours
- Remains waterproof for 30 days, even if your dog or cat swims or is bathed
- Easy to use spray bottle and is safe for use on puppies and kittens 8 weeks of age or older
- Kills fleas at all life stages, brown dog ticks, American dog ticks, lone star ticks, and deer ticks. Also helps control flea allergy dermatitis when applied regularly
Additional Info :
Item Dimensions | |
Height | 8.75 Inches |
Width | 2.75 Inches |
Length | 4 Inches |
In Conclusion
It is safe to say that you can use Frontline on your dog if they are already covered with fleas, but you will want to be sure to treat the area thoroughly. It will not kill the fleas that are already on your dog, but it is a good idea to look for the fleas and remove them before applying the product. If you find that there are still some fleas left, then you may need to reapply Frontline for Dogs or another product in order to completely get rid of them.