NEW CUSTOMERS SAVE 40% W/AUTOSHIPUse code NEW40 (Up to $30 max. Exclusions apply)
SAVE AN EXTRA $5 - $20 OFFUse code PETS in cart (Exclusions apply)
Kills Fleas |
![]() |
![]() |
![]() |
Repels Fleas |
![]() |
![]() |
![]() |
Kills Flea eggs and Larvae |
![]() |
![]() |
Prevents Development |
Kills Ticks |
![]() |
![]() |
![]() |
Repels Ticks |
![]() |
![]() |
![]() |
Kills and/or Repels Mosquitoes |
![]() |
![]() |
![]() |
Prevents Heartworm |
![]() |
![]() |
![]() |
Other Parasites Information | NA | Kills chewing lice and controls mites that may cause sarcoptic mange. | Controls adult hookworms and removes and controls adult roundworms & whipworms |
Waterproof (shampooing once a week can reduce effectiveness) |
![]() |
![]() |
N/A |
Safe for pregnant or nursing Pets |
![]() |
![]() |
![]() |
How long does it take to work | Reapply Activyl every 30 days. | Kills fleas and ticks with the same efficacy as Frontline Top Spot. | Begins to work Immediately, However, pre-existing flea populations may continue to develop and emerge. |
Taste | Applied to skin | Applied to Skin | Beef Flavor |
Active Ingredient(s) | indoxacarb | Fipronil | Milbemycin Oxime/Lufenuron |
RX Required |
![]() |
![]() |
![]() |
Dosage | |||
Usage |
![]() |
![]() |
![]() |
Video | Coming soon | Coming soon | Coming soon |
Vet Review | Another recently available new topical flea preventative for dogs and cats. This new product works by being activated by only the flea's enzyme systems into a flea specific mechanism which paralyzes and kills the adult flea. The company claims that it does not get into the blood stream, but stays only in the superficial skin layers of the pet. Any adult fleas which come into contact with this product are quickly killed so that fleas do not have to actually bite the pet, which is tremendously helpful in those flea-allergic pets, where it only takes a few flea bites to set off an extensive itchy allergic reaction. Another wonderful benefit of this product is that it is waterproof, which is especially helpful in those active outside pets who are exposed to rain or like to swim. This effective product starts working within 12 hours of application, where over 90% of adult fleas are killed. Another excellent benefit of this product is that it also inhibits the development of flea eggs and larvae in the environment, which is a big bonus since much of the flea life cycle occurs in the home environment. While Activyl is very safe and effective for most pets, I have seen occasional rare reactions in sensitive pets, which most commonly is seen as irritation or excessive itchiness at the site of application. While the company says that it is odorless, some of my clients have said that they do sense an odor within the first several days of application, as well as leaving an occasional oily film for the first day or two following application. This film, however usually quickly disappears. The only other very rare reactions include digestive upset and/or drooling/neurological reactions, and certainly if a pet has any chronic digestive weaknesses or history of seizures, etc then the local veterinarian should be consulted before applying the product. I give this product an overall rating of 4, with an ease of use of 4. | I recently completed a small clinical trial using Flea 4X topical product for dogs in my veterinary clinic. And I must say that the initial reports on efficacy and safety has been excellent. With the main ingredient being the tried and tested fipronil, this product is very effective in controlling fleas, ticks, chewing lice and mosquitoes. It is also labelled to control mites that cause sarcoptic mange in dogs as well. This product is a wonderful generic alternative to the Frontline product that has been out for years. Clients have loved the economic savings of this product over similar topical flea and tick preventatives. It is manufactured exclusively in the United States, as well as having the trustworthy and reliable 1800petmeds label on the packaging. It is also water proof for those canine patients who spend a lot of time outside and/or swimming during the summer months. Clients are reporting back to me quick flea and tick killing that lasts up to several weeks in treated pets. I highly recommend this product to those canine guardians seeking out an effective and economic alternative to similar products on the market. | Sentinel is a wonderful combination of the heartworm prevention pill interceptor and the flea control product program both in this one pill. Many clients enjoy the convenience of having such broad acting internal and external parasites in one pill, without having to worry about giving two separate medicines. Lufenuron, which is the main flea control ingredient, stops the flea life cycle in its track at the egg and larval stage, thus being like a birth control pill for fleas who get on our pets. Given that the main problem of fleas is how rapidly they reproduce, this pill literally stops escalating growth of flea populations, before they can become established in our homes, where most of the flea life cycle occurs. The main disadvantage to this product is that it does not kill or repel adult fleas, so in situations with already established heavy infestations, it is best combined with a great topical product like advantage or front line or with the oral adulticide flea pill Capstar for maximal effect. The only other rare disadvantage I see is the slight increase in reactions when two products are combined into one like this, but fortunately this is not common in clinical practice. With milbemycin for prevention of heartworms and controlling and treating most common intestinal worms, I overall highly recommend this versatile product. |