THE PET PHARMACY By Wendy C. Brooks, DVM, DipABVP Educational Director, VeterinaryPartner.com

Confused about flea protection? This FAQ compares all the currently available flea control products to assist you in determining which is right for your situation. These products are available at licensed veterinary hospitals. These tales do not include over-the-counter products (as would be sold in a grocery or pet supply store.

Table 1: Flea killing ingredient; flea sterilizing or additional ingredients; for dogs or cats; youngest age or size approved for use; waterproof or water resistant

Table 2: Approved for pregnancy or lactation (nursing); how long until maximum effect against fleas is reached; other parasites killed, controlled or repelled; how often applied or administered

Table 3: Oral or topical, prescription drug, non-prescription drug or insecticide; LD50 (lethal dose to 50% of the population)

Table 4: Year first made available in U.S.; manufacturer and link to manufacturer’s website; additional cautions

TABLE 1	Flea Killing Ingredient	Flea Sterilizing or Additional Ingredients	For Dogs or Cats	Youngest Age or Size Approved For Use	Waterproof or Water Resistant
Comfortis	spinosad	none	dog	14 weeks; at least 5 lbs	waterproof
Vectra 3D	dinotefuran & permethrin	pyriproxyfen (flea sterilizer)	dog	7 weeks; at least 2.5 lbs	waterproof
Vectra for Cats	dinotefuran	pyriproxyfen (flea sterilizer)	cat	8 weeks	water resistant
Promeris	metaflumizone	amitraz (for additional parasites)	dog	8 weeks	waterproof
Promeris Feline	metaflumizone	none	cat	8 weeks	waterproof
Revolution	selamectin	none	dog or cat	6 weeks puppies 8 weeks kittens	waterproof
Advantage	imidacloprid	none	dog or cat	7 weeks puppies 8 weeks kittens	water resistant
K9Advantix	imidacloprid & permethrin	none	dog	7 weeks	water resistant
Advantage Multi also called Advocate	imidacloprid	moxidectin (for additional parasites)	dog or cat	7 weeks puppies 9 weeks kittens	water resistant
Frontline	fipronil	none	dog or cat	8 weeks	waterproof
Frontline Plus	fipronil	methoprene (flea sterilizer)	dog or cat	8 weeks	waterproof
Program	none	lufenuron   (flea sterilizer)	dog or cat	4 weeks	waterproof
Sentinel	none	lufenuron  (flea sterilizer) & milbemycin (for additional parasites)	dog	4 weeks; at least 2 lbs	waterproof
Capstar	nitenpyram	none	dog or cat	4 weeks; at least 2 lbs	waterproof

TABLE 2	Approved for Pregnancy and Lactation (Nursing)	How Long until Maximum Effect against Fleas Is Reached?	Other Parasites Killed, Controlled or Repelled	How often Applied or Administered?
Comfortis	manufacturer recommends against use but not specifically labeled against	100% fleas dead in 4 hours	none	monthly
Vectra 3D	no	96% of fleas dead in 6 hours	kills ticks; repels flies and mosquitos	monthly
Vectra for Cats	no	98% of fleas dead in 6 hours	none	monthly
Promeris	no	24 hours to maximum effect	kills ticks	every 6 weeks (monthly recommended)
Promeris Feline	no	24 hours to maximum effect	none	every 7 weeks (monthly recommended)
Revolution	yes	42 hours to zero fleas	dogs: ticks, ear mites, sarcoptic mange mites, & heartworm larvae cats: hookworms, roundworms, ear mites & heartworm larvae	monthly
Advantage	manufacturer recommends consulting with veterinarian first	98% of pre-existing fleas dead in 12 hours; then new fleas in 2 hours	none	monthly
K9Advantix	no	98% of fleas dead in 12 hours	kills ticks; repels flies and mosquitos	monthly
Advantage Multi also called Advocate	no	98% of fleas dead in 12 hours	dogs: whipworms, hookworms, roundworms & heartworm cats: hookworms, roundworms, ear mites, & heartworm	monthly
Frontline	top spot yes; spray no	24 hrs to translocate, then 4-18 hours to kill fleas	kills ticks & lice	monthly
Frontline Plus	yes	24 hrs to translocate, then 4-18 hrs to kill fleas and 24-48 hours to kill ticks	kills ticks & lice	monthly
Program	yes	peak activity at 6 hours	none	monthly for oral; every 6 months for injectable
Sentinel	individual ingredients yes, but combination not approved	peak activity at 6 hours	hookworms, roundworms, whipworms & heartworm	monthly
Capstar	yes	maximum effect in 4 hours	none	as needed or daily (no lasting activity)

TABLE 3	Oral or Topical?	Prescription Drug, Non-Prescription Drug or Insecticide	Lethal Dose to 50% of the Population (the higher the number, the safer the product) (*What is LD50?)
Comfortis	oral (chewable)	prescription drug	>3,000 mg/kg in rats; >2.000 mg/kg in rabbits (translates to over 30 times recommended dose)
Vectra 3D	topical	insecticide	>2,400 mg/kg in rats for dinotefuran, >4,000 mg/kg in rats for topical permethrin
Vectra for Cats	topical	insecticide	>2,400 mg/kg in rats for dinotefuran
Promeris	topical	insecticide	>5,000 mg/kg in rats for metaflumizone, > 2,000 mg/kg in rats for amitraz
Promeris Feline	topical	insecticide	>5,000 mg/kg in rats (over 15 times recommended dose)
Revolution	applied topically, but rapidly absorbed through skin	prescription drug	>1,600 mg/kg in rats
Advantage	topical	insecticide	dermal dose: >5,000 mg/kg in rats orally: 450 mg/kg in rats
K9Advantix	topical	insecticide	imidacloprid dermal dose: >5,000 mg/kg in rats imidacloprid orally: 450 mg/kg in rats >4,000 mg/kg in rats for permethrin
Advantage Multi also called Advocate	topical	prescription drug	imidacloprid dermal dose: >5,000 mg/kg in rats imidacloprid orally: 450 mg/kg in rats >2,000 mg/kg in rabbits for moxidectin
Frontline	topical top spot or spray	insecticide	fipronil dermal dose: >5,000 mg/kg in rats fipronil orally: 750 mg/kg in rats
Frontline Plus	topical	insecticide	fipronil dermal dose: >5,000 mg/kg in rats fipronil orally: 750 mg/kg in rats methoprene orally: >34,600 in rats (virtually non-toxic)
Program	oral; or injectable for cats only	over the counter drug	orally: > 2,000 mg/kg in rats
Sentinel	oral	prescription drug	lufenuron orally: > 2,000 mg/kg in rats milbemycin ld50 information unavailable symptoms of tremors and incoordination result at 19 times recommended dose
Capstar	oral	over the counter drug	orally: 1,575 mg/kg in rats

 *LD50 stands for "lethal dose to 50% of a population." Typically lethal doses are expressed as oral (toxin taken by mouth) or by dermal (toxin placed on the skin). LD50s are usually determined with lab animal species such as rats, mice, and rabbits, but occasionally information is available for dogs. LD50's are expressed in milligrams of ingredient per kilogram of animal body weight (i.e. mg/kg) and provides a way to compare the toxicity of different substances. The higher the LD50, the less toxic a substance is. Some of the materials reviewed here are so safe that LD50 has not been determined and we can only say that it is greater than a certain amount tested. The highest numbers represent the safest numbers.

TABLE 4	Year First Made Available in U.S.	Manufacturer	Additional Cautions
Comfortis	2007	Lilly	should not be used in dogs with known seizure disorders
Vectra 3D/Vectra for Cats	2007/2008	Summit	none
Promeris	2007	Fort Dodge	amitraz may interact with some drugs
Promeris Feline	2007	Fort Dodge	none
Revolution	2000	Pfizer	pets should test negative for heartworm before use
Advantage	1996	Bayer	none
K9Advantix	2003	Bayer	do not use in cats (cats are sensitive to permethrin)
Advantage Multi also called Advocate	2007	Bayer	pets should test negative for heartworm before use
Frontline	1996	Merial	none
Frontline Plus	2000	Merial	none
Program	1994	Novartis	give with food
Sentinel	1997	Novartis	give with food; pets should test negative for heartworm before use
Capstar	2000	Novartis	none

Date Published: 1/1/2001
Date Reviewed/Revised: 09/30/2008