SENTINEL FLAVOR TABS 11-25LBS- milbemycin oxime, lufenuron tablet 
Virbac AH, Inc


Sentinel® flavor tabs® 11-25lbs

sentinel® flavor tabs®
(milbemycin oxime+lufenuron)

The palatable once-a-month prescription tablet that prevents heartworm disease and flea populations in dogs and puppies. SENTINEL® (milbemycin oxime/lufenuron) FLAVOR TABS® also controls flea populations, adult hookworm infections, remove and controls adult roundworm and whipworm infections in dogs and puppies.


Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian.


Not for human use. Keep this and all drugs out of reach of children.


SENTINEL FLAVOR TABS are available in four tablet sizes in color-coded packages for oral administration to dogs and puppies according to their weight. (See Dosage Section). Each tablet is formulated to provide a minimum of 0.23 mg/pound (0.5 mg/kg) of milbemycin oxime and 4.55 mg/pound (10 mg/kg) body weight of lufenuron.

Milbemycin oxime consists of the oxime derivatives of 5-didehydromilbemycins in the ratio of approximately 80% A4 (C32H45NO7, MW 555.71) and 20% A3 (C31H43NO7, MW 541.68). Milbemycin oxime is classified as a macrocyclic anthelmintic.
Lufenuron is a benzoylphenylurea derivative with the following chemical composition:
N-[2,5-dichloro-4-(1,1,2,3,3,3, - hexafluoropropoxy)-phenylaminocarbonyl-2,6-difluorobenzamide (C17H8Cl2F8N2O3, MW 551.15). Benzoylphenylurea compounds, including lufenuron, are classified as insect development inhibitors (IDIs).

Mode of Action

Milbemycin oxime, one active ingredient in SENTINEL FLAVOR TABS, is a macrocyclic anthelmintic which is believed to act by interfering with invertebrate neurotransmission.
Milbemycin oxime eliminates the tissue stage of heartworm larvae and the adult stage of hookworm (Ancylostoma caninum), roundworm (Toxocara canis and Toxascaris leonina) and whipworm (Trichuris vulpis) infestations when administered orally according to the recommended dosage schedule.
Lufenuron, the other active ingredient in SENTINEL FLAVOR TABS, is an insect development inhibitor which breaks the flea life cycle by inhibiting egg development. Lufenuron's mode of action is interference with chitin synthesis, polymerization and deposition. Lufenuron has no effect on the adult flea. After biting a lufenuron-treated dog, the female flea ingests a blood meal containing lufenuron which is subsequently deposited in her eggs. Lufenuron prevents most flea eggs from hatching or maturing into adults and thus prevents and controls flea populations by breaking the life cycle. (See Efficacy).


SENTINEL FLAVOR TABS are indicated for use in dogs and puppies, four weeks of age and older, and two pounds body weight or greater. SENTINEL FLAVOR TABS are also indicated for the prevention of heartworm disease caused by Dirofilaria immitis for the prevention and control of flea populations, the control of adult Ancylostoma caninum (hookworm), and the removal and control of adult Toxocara canis and Toxascaris leonina (roundworm) and Trichuris vulpis (whipworm) infections.
Lufenuron controls flea populations by preventing the development of flea eggs and does not kill adult fleas. Concurrent use of an adulticide product may be necessary for adequate control of adult fleas.
Without concurrent use of an adulticide, adequate flea control may not be achieved in dogs that have repeated exposure to flea infested animals or environments.


Do not use in puppies less than four weeks of age and less than two pounds of body weight. Prior to administration of SENTINEL FLAVOR TABS, dogs should be tested for existing heartworm infections. Infected dogs should be treated to remove adult heartworms and microfilariae prior to initiating treatment with SENTINEL FLAVOR TABS. Mild, transient hypersensitivity reactions manifested as labored respiration, vomiting, salivation and lethargy have been noted in some treated dogs carrying a high number of circulating microfilariae.
These reactions are presumably caused by release of protein from dead or dying microfilariae.
SENTINEL FLAVOR TABS immediately break the flea life cycle by inhibiting egg development. However, preexisting flea populations may continue to develop and emerge after treatment with SENTINEL FLAVOR TABS has begun. Based on results of clinical studies, this emergence generally occurs during the first 30-60 days. Therefore, noticeable control may not be observed until several weeks after dosing when a preexisting infestation is present. Cooler geographic areas may have longer lag periods due to a prolonged flea life cycle. The concurrent use of an approved adulticide may be employed depending on the severity of the infestation.
If a SENTINEL FLAVOR TABS-treated dog comes in contact with a flea-infested environment, adult fleas may infest the treated animal. These adult fleas are unable to produce viable offspring. The temporary use of an adulticide product may be necessary to kill these adult fleas.

Efficacy: Milbemycin Oxime

Milbemycin oxime provided complete protection against heartworm infection in both controlled laboratory and clinical trials.
In laboratory studies, a single dose of Milbemycin oxime at 0.5 mg/kg was effective in removing roundworm, hookworm and whipworm. In well-controlled clinical trials, Milbemycin oxime was also effective in removing roundworms and whipworms and in controlling hookworms.

Efficacy: Lufenuron

Lufenuron provided 99% control of flea egg development for 32 days following a single dose of lufenuron at 10 mg/kg in studies using experimental flea infestations. In well-controlled clinical trials, when treatment with lufenuron tablets was initiated prior to the flea season, mean flea counts were lower in lufenuron-treated dogs versus placebo-treated dogs. After 6 monthly treatments, the mean number of fleas on lufenuron-treated dogs was approximately 4 compared to 230 on placebo-treated dogs.
When treatment was initiated during the flea season, lufenuron tablets were effective in controlling flea infestations on dogs that completed the study. The mean flea count per lufenuron-treated dog was approximately 74 prior to treatment but had decreased to 4 after six monthly doses of lufenuron. A topical adulticide was used in the first eight weeks of the study to kill the pre-existing adult fleas.

Safety: Milbemycin Oxime

Milbemycin oxime has been tested safely in over 75 different breeds of dogs, including collies, pregnant females, breeding males and females, and puppies over two weeks of age. In well-controlled clinical field studies 786 dogs completed treatment with milbemycin oxime. Milbemycin oxime was used safely in animals receiving frequently used veterinary products such as vaccines, anthelmintics, antibiotics, steroids, flea collars, shampoos and dips.
Two studies in heartworm-infected dogs were conducted which demonstrated mild, transient hypersensitivity reactions in treated dogs with high microfilaremia counts (see Precautions for reactions observed]. Safety studies in pregnant dogs demonstrated that high doses (1.5 mg/kg = 3X) of milbemycin oxime given in an exaggerated dosing regimen (daily from mating through weaning), resulted in measurable concentrations of the drug in milk.
Puppies nursing these females which received exaggerated dosing regimens demonstrated milbemycin-related effects. These effects were directly attributable to the exaggerated experimental dosing regimen. The product is normally intended for once-a-month administration only. Subsequent studies included using 3X daily from mating to one week before weaning and demonstrated no effects on the pregnant females or their litters. A second study where pregnant females were dosed once at 3X the monthly use rate after before, on the day of or shortly after whelping resulted in no effects on the puppies.
Some nursing puppies, at 2, 4, and 6 weeks of age, given greatly exaggerated oral doses of milbemycin oxime (9.6 mg/kg = 19X) exhibited signs typified by tremors, vocalization and ataxia. These effects were all transient and puppies returned to normal within 24 to 48 hours.
No effects were observed in puppies given the recommended dose of milbemycin oxime (0.5 mg/kg). This product has not been tested in dogs less than 2.2 pounds in body weight.
A rising-dose safety study conducted in rough-coated collies manifested a clinical reaction consisting of ataxia, pyrexia and periodic recumbency in one of fourteen dogs treated with milbemycin oxime at 12.5 mg/kg (25X monthly use rate). Prior to receiving the
12.5 mg/kg dose (25X monthly use rate) on day 56 of the study, all animals had undergone an exaggerated dosing regimen consisting of 2.5 mg/kg milbemycin oxime (5X monthly use rate) on day 0, followed by 5.0 mg/kg (10X monthly use rate) on day 14 and 10.0 mg/kg
(20X monthly use rate) on day 32. No adverse reactions were observed in any of the collies treated with this regimen up through the 10.0 mg/kg (20X monthly use rate) dose.

Safety: Lufenuron

Lufenuron tablets have been used and tested safely in over forty breeds of dogs, including pregnant females, breeding males and puppies over six weeks of age. In well-controlled clinical trials, 151 dogs completed treatment with lufenuron tablets. Lufenuron tablets were used safely in animals receiving frequently used veterinary products such as vaccines, anthelmintics, antibiotics and steroids. In a ten-month study, doses up to 10X the recommended dose rate of 10 mg/kg caused no overt toxicity. A single dose of 200 mg/kg (20X the recommended dose rate) had no marked effect on adult dogs, but caused decreased activity and appetite in eight week old puppies. Mean body weights of male and female puppies were higher in treated versus control group at the end of the study. In specifically designed target animal safety studies, lufenuron tablets were tested with concurrent administration of flea adulticides containing carbaryl, permethrin, chlorpyriphos and cythioate. No toxicity resulted from these combinations. Lufenuron tablets did not cause cholinesterase inhibition nor did they enhance cholinesterase inhibition caused by exposure to organophosphates.
Four reproductive safety studies were conducted in breeding dogs with lufenuron tablets: two laboratory and two well-controlled clinical studies. In one of the laboratory studies, where
lufenuron was administered to beagle dogs at doses equivalent to 90X (3X daily) the monthly recommended dose of 10 mg/kg, the ratio of gravid females to females mated was 8/8 or 100% in the control group and 6/9 or 67% in the lufenuron-treated group. The mean number of pups per litter was two animals higher in the treated versus control groups and the mean birth weights of pups from treated bitches in this study was lower than control groups.
These pups grew at a similar rate to control pups. There was a higher incidence of four clinical signs in the lufenuron-treated versus control group: nasal discharge, pulmonary congestion, diarrhea/dehydration and sluggishness. The incidence of these signs was transient and decreasing by the end of lactation. Results from three additional reproductive safety studies, one laboratory and two clinical field studies evaluating eleven breeds of dogs, did not demonstrate any adverse findings for the reproductive parameters measured including fertility, pup birth weights and pup clinical signs after administration of lufenuron up to 5X the recommended monthly use rate.
Data from analysis of milk from lactating animals treated with lufenuron tablets at 2X and 5X the recommended monthly use rate demonstrates that lufenuron concentrates in the milk of these dogs. The average milk:blood concentration ratio was approximately 60 (i.e., 60X higher drug concentrations in the milk compared to drug levels in the blood of treated bitches). Nursing puppies averaged 8-9 times higher blood concentrations of lufenuron compared to their dams.


SENTINEL FLAVOR TABS are given orally, once a month, at the recommended minimum dosage of 0.23 mg/lb (0.5 mg/kg) milbemycin oxime and 4.55 mg/lb (10mg/kg) lufenuron.

Dogs over 100 lbs are provided the appropriate combination of tablets.



SENTINEL FLAVOR TABS are palatable and most dogs will consume the tablet when offered by the owner. As an alternative to direct dosing, the tablets can be hidden in food. Be certain the dog consumes the entire tablet or tablets. Administer SENTINEL FLAVOR TABS to dogs immediately after or in conjunction with a normal meal. Food is essential for adequate absorption of lufenuron. Watch the dog closely following administration to be sure the entire dose has been consumed. If it is not entirely consumed, redose with the full recommended dose as soon as possible.

SENTINEL FLAVOR TABS must be administered monthly, preferably on the same date each month. Treatment with SENTINEL FLAVOR TABS may begin at any time of year. In geographic areas where mosquitoes and fleas are seasonal, the treatment schedule should begin one month prior to the expected onset and should continue until the end of "mosquito and flea season." In areas with year-round infestations, treatment should continue through the entire year without interruption.
If a dose is missed and a 30-day interval between dosing is exceeded, administer SENTINEL
FLAVOR TABS immediately and resume the monthly dosing schedule. If SENTINEL FLAVOR
TABS replace daily diethylcarbamazine (DEC) for heartworm prevention, the first dose must be given within 30 days after the last dose of DEC.

Recommended Dosage Schedule 
Body WeightMilbemycin Oxime
Per Tablet
Per Tablet
2 to 10 lbs.2.3 mg46 mg
11 to 25 lbs.5.75 mg115 mg
26 to 50 lbs.11.5 mg230 mg
51 to 100 lbs.23 mg460 mg

Adverse Reactions

The following adverse reactions have been reported in dogs alter giving milbemycin oxime or lufenuron: vomiting, depression/lethargy, pruritus, urticaria, diarrhea, anorexia, skin congestion, ataxia, convulsions, hypersalivation, and weakness.

To report suspected adverse drug events, contact Virbac at 1-800-338-3659.

For additional information about adverse drug experience reporting for animal drugs,
contact FDA at 1-888-FDA-VETS or

How Supplied

SENTINEL FLAVOR TABS are available in four tablet sizes (see Dosage Section) formulated according to the weight of the dog. Each tablet size is available in color-coded packages of 6 or 12 tablets each, which are packaged 10 per display carton.

Storage Conditions

Store in a dry place at controlled room temperature, between 59° and 77°F (15-25°C).

Questions? Comments?

Please Call 1-800-338-3659
Visit our website at

Manufactured for.
Virbac AH, Inc.
P.O. Box 162059
Ft Worth, TX 76161

NADA #141-084, Approved by FDA

© 2016 Virbac Corporation. All Rights Reserved.
SENTINEL and FLAVOR TABS are registered trademarks of Virbac Corporation.





Recommended for dogs and puppies


Sentinel® flavor tabs®

(milbemycin oxime+lufenuron)

Once-a-month flavored tablets

6 pack

Prevents Heartworm Disease and Flea Populations in Dogs and Puppies

Also controls flea populations, adult hookworm infections, remove and controls adult roundworm and whipworm infections in dogs and puppies.

Keep this and all drugs out of reach of children.

Net contents: 6 tablets, 5.75mg milbemycin oxime and 115mg lufenuron each

Give with a meal

CAUTION: Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian.

Product #52221 NADA141-084

Approved by FDA

Important directions for use

  • To ensure adequate absorption, always administer SENTINEL® (milbemycin oxime/lufenuron) FLAVOR TABS® to dogs immediately after or in conjunction with a normal meal.
  • SENTINEL FLAVOR TABS have no effect on adult fleas, but controls flea populations by breaking the flea cycle at the egg stage.
  • Treatment may begin at any time of the year. In geographic areas where fleas and mosquitos are seasonal, treatment should begin several weeks prior to the expected onset and should continue until the end of the flea and mosquito season. In areas with year-round infestations, treatment should continue the entire year without interruption.
  • It is important to treat all dogs in the household for fleas. Cats in the same household should be treated with approved products like lufenuron.
  • SENTINEL FLAVOR TABS must be administered monthly, preferably on the same date each month.
  • For full product information, see enclosed inserts.
  • If you have any questions concerning the use of this product, contact your veterinarian, who is your pet's healthcare expert.

For technical assistance call 1-800-338-3659

Sentinel® flavor tabs®
(milbemycin oxime+lufenuron)

Made in France.
Manufactured for Virbac AH, Inc.
P.O. Box 162059, Ft. Worth, TX 76161

Storage conditions: Store in a dry place at controlled room tempterature, between 59° and 77°F (15-25°C).

image description

milbemycin oxime, lufenuron tablet
Product Information
Product TypePRESCRIPTION ANIMAL DRUGItem Code (Source)NDC:51311-125
Route of Administrationoral
Active Ingredient/Active Moiety
Ingredient NameBasis of StrengthStrength
Product Characteristics
ColorbrownScoreno score
ShapePENTAGON (5 sided)Size10mm
#Item CodePackage DescriptionMarketing Start DateMarketing End Date
1NDC:51311-125-091 in 1 BOX, UNIT-DOSE
Marketing Information
Marketing CategoryApplication Number or Monograph CitationMarketing Start DateMarketing End Date
Labeler - Virbac AH, Inc (131568396)
Registrant - Virbac AH, Inc (131568396)
NameAddressID/FEIBusiness Operations
Elanco France S.A.S.736833104manufacture, analysis
NameAddressID/FEIBusiness Operations
Alps Pharmaceutical Ind. Co. Ltd690535893api manufacture
NameAddressID/FEIBusiness Operations
Lonza AG480007517api manufacture
NameAddressID/FEIBusiness Operations
Packaging Coordinators. LLC078525133pack, label

Revised: 4/2017
Virbac AH, Inc