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Sentinel Rx

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Product Overview

How To Use

What’s in it?



Questions & Answers

Product Description

Sentinel is a flavored tablet used to prevent heartworms, control and prevent fleas, control adult hookworms, and control and remove adult roundworm and whipworm. See the Allivet Heartworm Comparison chart to find which heartworm prevention is best for your pet.

What is Sentinel?

Sentinel (milbemycin oxime/lufenuron) Flavor Tabs are chewable tablets manufactured by Virbac that control flea populations and adult hookworms, and remove and control adult roundworm and whipworm infections in dogs and puppies. In addition Sentinel helps prevent heartworms.

Who is Sentinel for?

For puppies and dogs 4 ages 4 weeks and up.

Why use Sentinel?

Sentinel is an oral monthly tablet with a savory beef flavor. It:
  • Protects against many types of infections and infestations
  • Controls existing flea infestations
  • Prevents and treats heartworms
  • Controls and treats roundworms and whipworms

How does Sentinel work?

  • Lufenuron and milbemycin oxime eradicate infestation of worms and control fleas
  • Milbemycin oxime, a macrocylic anthelmintic, is believed to interfere with invertebrate neurotransmission
  • Milbemycin oxime is known to eliminate heartworm larvae in the tissue stage, along with roundworm (Toxascaris leonina and Toxocara canis), whipworm (Trichuris vulpis), and hookworm (Ancyclostoma caninum) when the recommended dosage schedule is followed
  • Lufenuron is shown to controlfleas by preventing flea eggs from developing, but it does not kill fleas in the adult stage. An adulticide may be used concurrently to control adult fleas adequately.



Active ingredient(s):

Milbemycin Oxime - Lufenuron

How is Sentinel sold?

Sentinel is sold in four tablet sizes in color-coded packages for oral administration to dogs and puppies according to their weight (see How to Use). 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.

What are the side effects of Sentinel?

The following side effects have been reported:
  • Diarrhea
  • Vomiting
  • Loss of appetite
  • Depression
  • Lethargy
  • Staggering
  • Drooling
  • Seizures

What special precautions are there?

  • Sentinel should not be given to puppies under 4 weeks old or under 2 pounds.
  • Your dog should be tested for heartworms prior to taking Sentinel.

What to do if overdose?

Contact your closest emergency pet hospital.

How can I store Sentinel?

Store at room temperature. Keep out of the reach of children.

Helpful Tips:

Sentinel can be used together with Capstar (nitenpyram) to prevent flea eggs from hatching and to kill mature fleas. Please reference the included Supplemental Package Insert for more information about the concurrent use of two flea prevention products.

Pharmacists are standing by to offer Pet Parent counseling regarding prescription medication purchased from Allivet before and after dispensing. Pharmacists on duty are available Monday-Friday, 9:30AM - 5:30PM EST and will be on call Saturday 12:00PM - 4:00PM EST for consultation.


Sentinel is 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 (10 mg/kg) lufenuron. Please see separate insert in this package for concurrent dosing of Sentinel Flavor Tabs and Capstar Tablets.

Flavor Tabs are palatable and most dogs will consume the tablet when offered by the owner. If you are having trouble getting your dog to eat the tablets, they can be hidden in food as an alternative to direct dosing. Make sure dog consumes the entire tablet or tablets. 

Administer Flavor Tabs immediately after or in conjunction with a normal meal. Food is essential for adequate absorption of lufenuron. Watch your 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 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.
Sentinel for Flea Control
Give your Flavor Tabs once per month to prevent and control flea populations. Sentinel Flavor Tabs contain lufenuron. Lufenuron controls flea populations by preventing the development of flea eggs and does not kill mature fleas. If a dog currently has a flea infestation, more rapid relief can be accomplished by adding Capstar. Capstar Tablets contain nitenpyram and are effective for the treatment of flea infestations. Nitenpyram starts killing adult fleas within 30 minutes of administration. Administer the treatment as follows:
- Give your dog Capstar Tablets once per week until adult fleas are no longer observed.
- For a severe flea infestation, administer Capstar Tablets twice per week until adult fleas are no longer observed.
- Additional Capstar Tablets may be administered as needed to kill the occasional adult flea picked up from infested environments.
- It is important to treat all cats and dogs in the household. All cats should be treated with approved products like lufenuron in combination with nitenpyram as needed. Fleas can reproduce on untreated pets and allow infestations to persist.
The combination of Sentinel Flavor Tabs and Capstar Tablets should be administered according to the following schedule. Weigh your dog prior to administration to ensure proper dosage. Do not administer to dogs under 2 pounds or less than 4 weeks of age.
Administer with a normal meal.

Recommended Dosage Schedule: 
Dog’s Weight  /  Milbemycin Oxime Per Tablet  /  Lufenuron Per Tablet
2 to 10 lbs.    /                  2.3 mg                   /                46 mg
11 to 25 lbs. /                   5.75 mg                 /               115 mg
26 to 50 lbs. /                  11.5 mg                 /                230 mg
51 to 100 lbs. /                23 mg                   /                 460 mg
For dogs over 100 pounds give the appropriate combination of tablets.

Main Ingredients

The active ingredients present in Sentinel Flavor Tabs are milbemycin oxime and lufenuron.

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Customer Submitted Questions

What happens if my dog's weight is in between

1 Answer

is sentinel the only tablet I HAVE to give my dog ...since its for heartworm prevention and also controls flea population?

1 Answer

Does this product prevent BOTH heartworm & Flea & Tick?

1 Answer
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