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Sentinel Flavor Tabs for Dogs

Sentinel Flavor Tabs for Dogs

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  • Description
  • Ingredients
  • Directions
  • FAQ
  • Reviews


Sentinel Flavor Tabs is a preventive for heartworms, adult roundworms, adult hookworms and whipworms for your dog. Sentinel also prevents the development of flea eggs on your pet by breaking the flea life cycle. Sentinel can be taken along with Capstar for a more thorough flea treatment program. Sentinel requires a prescription from a veterinarian in order to be dispensed to your pet.


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.

Key Benefits

  • Prevents heartworm disease
  • Comes in palatable beef flavored tabs
  • Easy to administer just once a month
  • Controls flea population
  • Controls hookworms
  • Removes and controls roundworms
  • Removes and controls whipworms

How It Works

Milbemycin oxime eliminates the tissue stage of heartworm larvae and the adult stage of hookworm, roundworm, and whipworm infestations. Lufenuron, the other active ingredient, is an insect development inhibitor that breaks the flea life cycle by inhibiting egg development. Lufenuron prevents most flea eggs from hatching or maturing into adults and thus prevents and controls flea populations by breaking the life cycle.


Do not use in puppies less than four weeks of age and less than two pounds of body weight. Dogs should be tested for existing heartworm infections prior to initiating treatment with Sentinel Flavor Tabs. Infected dogs should be treated to remove adult heartworms and microfilariae prior to initiating treatment with Sentinel Flavor Tabs.

Prescription Required

NADA 141-084


Active Ingredient (per tablet)Milbemycin OximeLufenuron
Sentinel Brown2.3 mg46 mg
Sentinel Green5.75 mg115 mg
Sentinel Yellow11.5 mg230 mg
Sentinel White23 mg460 mg

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.



Give Sentinel exactly as directed by the veterinarian. If you do not understand the directions ask your pharmacist or veterinarian to explain them to you. The usual dose of Sentinel for dogs 2 to 10 pounds is 2.3mg/46mg, 11 to 25 pounds is 5.75mg/115mg, 26 to 50 pounds is 11.5mg/230mg and 51 to 100 pounds is 23mg/460mg given once a month year-round. For dogs over 100 pounds give the appropriate combination of tablets.


Heartworm testing should be performed prior to the start of prevention therapy. If your pet is off Sentinel for 6 months or less, re-start the medication and test after 6 months since microfilaria, that take 6 months to mature, will result in a positive test result. Store Sentinel at room temperature. Do not remove the tablet from its wrapper until ready to give the medicine. Keep this medication away from children and pets. Consult your veterinarian for pregnant or lactating dogs.

View Sentinel Flavor Tabs Drug Facts Sheet.

Quick Tips

  • Give Sentinel Flavor Tabs once a month on the same day of each month year-round.
  • Sentinel Flavor Tabs is for use in dogs only. Do not give to cats.
  • Watch your dog closely following dosing to be sure the entire dose has been swallowed. If it is not completely swallowed, give one more full recommended dose as soon as possible.
  • Do not remove Sentinel from its wrapper until ready to give to your pet.

Dosage Table

WeightMonthly Dosage
2-10 lbsOne Tablet (Brown)
11-25 lbsOne Tablet (Green)
26-50 lbsOne Tablet (Yellow)
51-100 lbsOne Tablet (White)
Over 100 lbsGive combination of Flavor Tabs based on weight

Storage Directions

Should be stored at room temperature between 59° and 77°F (15-25°C). Keep out of reach of children.


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

Adverse Reactions

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


How often do I give my dog Sentinel Flavor Tabs?

For optimal protection against 5 kinds of parasites, including fleas and heartworms, you should administer Sentinel Flavor Tabs every 30 days.

How do I give my dog Sentinel Flavor Tabs?

Sentinel Flavor Tabs are chewable tablets that are given by mouth along with a meal. Giving the product with a meal helps ensure full absorption of the medicine.

How are Sentinel Flavor Tabs (milbemycin / lufenuron) different from Heartgard Plus (ivermectin / pyrantel)?

Both products protect dogs against heartworms, roundworms, and hookworms, but Sentinel Flavor Tabs also protect against 2 important and common parasites that Heartgard Plus doesn’t: fleas and whipworms.

Why should I give my dog Sentinel Flavor Tabs?

In addition to providing flea and heartworm protection, you’ll also be protecting your dog against common intestinal parasites—roundworms, hookworms, and whipworms.


Review Summary
83 Reviews
90% (75)
8% (7)
0% (0)
1% (1)
0% (0)
96% Recommend this product (80 of 83 responses)
By Bronte
Enid, ok
Great communication
June 7, 2015
Highly recommended seller and product! They made sure to stay in contact while waiting for my vet to respond. They were very fast and professional ! The product is great too my dog has been happy and healthy . This is by far the best price including shipping that I was able to find.
By Melodie
Minneapolis, MN
Great Deal
March 11, 2020
Trusted and great product for a great price!
ProsPrice Quality
By DunPainted1
Plant City, FL
Great service, fast shipping
February 14, 2020
Will keep ordering !
By G-Mom
Austin, TX
Good Price - Fast Shipping.
February 10, 2020
Good Price and Fast Shipping. Thanks!
By Sheila
Crossville, TN
Good Price
February 8, 2020
Worked with me getting the ok from my vet and getting the pills to me in time..Thanks
By Louise
Wyomissing, PA
Safe heartworm medication
February 6, 2020
I have used Sentinel for 25 years for all 4 of my dachshunds and never had a reaction. Recently I got a mini doxie, who at adult weight is only 11.3 pounds, and the vet said even though he was on the low side of the Sentinel green (11-25 pounds), he still recommended the “green†because it is one of the safest on the market. Love the product; just have to be vigilant with remembering to give the pill. I always start them on the first of the month so it’s easy to remember!
ProsOnce a month oral tablet they can chew if you choose. Also, no mess since it’s a heartworm and flea medication.
ConsRemembering to give the pill.
By Renee' K.
Best Heartworm Protection and Flea Population Prevention
January 24, 2020
I've been using this product for all the dogs in my life for over 20 years - most of which time I've lived in the heartworm rampant states of the Carolinas & Texas - and have never had a dog come up heartworm positive, or have I ever had a dog have a negative reaction or long-term effect from this medication.
It also does help to effectively prevent flea populations in dogs and the environments (indoor & outdoor) in which they live without the seizure and gastrointestinal side effects of the newer flea prevention oral medication pills. I actually researched this topic in detail & found that the active flea prevention ingredient in Sentinel has the best track record of pet safety over ALL the other oral meds on the market! BUT, it must be noted that the company is emphatic that the flea protection lasts only 32 days, and it takes UP TO SEVEN DAYS to become effective in the dog's system again if you let the 32 days lapse before readministering! So don't delay a dose, and do so EXACTLY @ the 30 day mark! -Or else you could be introducing flea populations to your dog & environment!! I did so once when we went on a 2 week trip, & I forgot my dog's monthly pill, so she was late in getting her dose by 5 days.... Never again will I do that! Apparently she picked up fleas @ a hotel on the way home, of which I wasn't aware of until I got home, so the fleas contaminated & repopulated not only my truck, but also my house & yard! It took me over a month to have a totally flea-free environment again, & I had to do a LOT of house cleaning in that time (to suck up & wash away untreated flea eggs & larvae), as well as I had to bomb my truck & spray my yard - which I do NOT like doing!
Anyway, I learned my lesson that if I'm traveling, just double-protect them with a good spot-on product, like Advantage II, AND DON'T FORGET TO TAKE THE NEXT MONTH's PILL WITH ME!! LOL
ProsExtremely effective heartworm prevention with a long track record, and is the safest heartworm prevention and flea population protection product on the market today.
ConsMust be readministered within no later than 32 days from previous dose to maintain continuous flea population prevention protection.
By Kathy
New Hampshire
January 23, 2020
My vet recommends this. My 2 dogs have taken it for years. No side effects.
By Leigh
Best prices,
January 19, 2020
I have 2 dogs and am always shopping for the best prices on heartworm pills. I purchase a years worth at a time for both and EntirelyPets has the best prices & fast and friendly service!
By Annie
Easy and effective
January 19, 2020
I’ve used Sentinel for years. The dogs love them. I just add it to their breakfast once a month and I’m done with heartworm prevention! Couldn’t be any easier,,
By Kenny
Bradenton, Florida
Excellent Pricing
December 22, 2019
The price for Sentinel was significantly less than the other sites I have purchased the product from. Delivery was timely and without delay!
By Karen
Corpus christi
December 4, 2019
I have been buying these from Petmeds for years thinking I was getting a good deal on the price. I saved $18.00 buying from Entirely Pets Pharmacy for the exact same product!! I am very happy with them!
By Dora R.
Norman, OK
Entirely Pets
November 27, 2019
Great prices and quick service!
By Gary
Best product ever.
November 20, 2019
Just 1 pill no messy oil on back works great
ProsJust 1 pill no messy oil on back works great
By Gary
Best product ever
November 20, 2019
Just 1 pill no messy oil on back works great as usual
ProsJust 1 pill no messy oil on back works great
By Gary
Best product
November 20, 2019
Just 1 pill no messy oil on back works great
ProsJust 1 pill no messy oil on back works great
By My T.
Coral Springs, Florida
Great savings
November 1, 2019
I have purchased this elsewhere for far much more and not only was Entirely Pets cheaper but their customer service could not be beat. They went over and above to get my script transferred to them and to get the Sentinel to me for my Tucker on time for his next dose. They were great!

Merchant Response:Hi, I am so glad to hear that we were able to get Tucker his medication. As a pet owner myself I know how important our pets are, they are like our family. I would also like to personally thank you for ordering with our EntirelyPets Pharmacy. We appreciate your business and the opportunity to serve you.
ProsBest prices and service
By Cindy
Great deal
September 12, 2019
Great deal, timely delivery, overall happy
By Lynne
Great product
September 10, 2019
Great product
By Sheila
Always pleased
September 8, 2019
Have used Sentinel for years with three dogs. Always pleased !
By Pat
Doylestown, OH
Great Product!
September 7, 2019
Have been using for years. Protects for some parasites that other products do not. Their products were not avail able about a 6 years ago for a period of time so I used another product recommend by the vet in the interim. My boy ended up with worms that were hard to treat and he somehow contracted an infection that got into his heart and we lost him. We did a necropsy to find out his cause of death since we had multiple dogs. We will never really know if the worms caused the infection but it will always be suspect since he was so recently treated for the worms. That was the only recent health issue he presented. Now I am adamant about using Sentinel or Interceptor for the most complete parasite protection.
By Sue
Cheaper than anywhere
August 30, 2019
Best price out there. Quick ship.
Merchant Response: Hi Sue, I would like to personally thank you for ordering with our EntirelyPets Pharmacy. We appreciate your business and the opportunity to serve you.
By Cocker M.
Tulsa Oklahoma
Highly Recommend
August 24, 2019
I have been using Sentinel and Interceptor for 20 yrs on 6 dogs (cockers/shelties. The only difference between the 2 is Sentinel has a flea med that stops them from reproducing. Same Heartworm ingredient. No side effects from any of my dogs. My vet highly recommends as the most effective and safest.
ConsNone of my dogs like the chewable flavor but I just disguise it in their food or a piece of bread and they take it fine.
By Helen
Menifee CA
works well for 3 dogs
May 9, 2019
My pets haven't had any issues
ProsConvenient small tablet
By Mike S.
Orange, Texas
excellent price and service
February 21, 2019
Entirely Pets has the best prices for RX products for your animals.
ProsBest price and service!
By Fern
Very good product and exceptional price
December 28, 2018
The cheapest price anywhere and they contacted my vet quickly. Got my things quickly. I use this product because it prevents flea eggs from hatching and we had a flea problem. My puppy also wont eat the other products for heartworm.
ProsSmall pill
ConsFlavoring got licked off so i finally coated it with peanut butter to get him to take it. Hes a puppy and has teeth issues but he finally took it. The soft type dose didnt work for him.
By Deb
December 15, 2018
Flea free no greasy drops to put on pet
By Donna
Napa, CA
Great product
December 9, 2018
I like Sentinel best because it covers more than just heart worms. I don't have to do something more for fleas.
By Gary
August 9, 2018
Have been using this product for several years. Seems to be very effective.
By Sandy C.
Decatur, Illinois
Payton heart worm
July 21, 2018
Very happy with this company, Very prompt to respond to my request. They called my vet immediately and got the ok for the prescription. Will definitely use again.

Sandy C
Decatur, Il
Merchant Response:Sandy, That's high praise and we thank you. We strive to be better every day.

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