How Often Should You Give Sentinel to Dogs?
Sentinel Flavor Tabs are a monthly, prescription-only chewable tablet designed to protect dogs from a range of parasites, including heartworms, fleas, and intestinal worms. Understanding the correct administration schedule is crucial to maintaining your dog’s health and ensuring the medication works effectively.
Monthly Administration Is Key
The most important thing to remember about Sentinel is that it must be administered once every 30 days. Each tablet provides protection for a month, and consistency is necessary to prevent gaps that could lead to infection from parasites such as heartworms, hookworms, roundworms, whipworms, and flea eggs.
Administering Sentinel
- Give the tablet orally once a month, ideally on the same date each time.
- Administer with or immediately after a meal to support proper absorption—especially of the active ingredient lufenuron.
- The tablet is typically palatable (beef or pork-liver flavored) and can be given by hand or hidden in food.
Monitor your dog to ensure that the full dose is consumed. If your dog doesn't eat it voluntarily, try placing it directly in the mouth or crushing and mixing it with a small amount of food.
What to Do If You Miss a Dose
- If more than 30 days pass between doses, give the missed dose as soon as possible and resume the monthly schedule.
- Do not double dose to make up for a missed one.
- Ensure heartworm testing is done annually to check for any infections before continuing treatment.
Why Monthly Dosing is Crucial
Each Sentinel tablet is formulated to provide 30-day coverage. Giving it monthly helps build a continuous defense against parasites:
- Milbemycin oxime eliminates developing heartworm larvae and treats adult roundworms and hookworms.
- Lufenuron inhibits the development of flea eggs, reducing infestations.
A monthly schedule ensures that these benefits overlap perfectly, protecting your dog without interruption.
Correct Dosage by Weight
Sentinel tablets come in four sizes color-coded by the dog’s body weight:
- 2–10 lbs: 2.3 mg milbemycin oxime / 46 mg lufenuron
- 11–25 lbs: 5.75 mg / 115 mg
- 26–50 lbs: 11.5 mg / 230 mg
- 51–100 lbs: 23 mg / 460 mg
For dogs over 100 lbs, appropriate combinations of tablets should be used under veterinary guidance.
Before Starting Sentinel
- Ensure your dog is at least 4 weeks old and weighs over 2 lbs.
- Get your dog tested for heartworm before starting treatment.
- If your dog is heartworm-positive, they need treatment before starting Sentinel to avoid adverse effects.
Safety and Side Effects
Sentinel is considered safe for puppies, adults, pregnant, and breeding dogs. However, hyper-sensitive dogs (especially those with high microfilariae counts) can show mild side effects. Common side effects include:
- Vomiting
- Lethargy
- Itching
- Diarrhea
- Hypersalivation
- Loss of appetite
In rare cases, more severe symptoms like ataxia and convulsions can occur. Always consult your vet if you notice anything unusual after dosing.
Storage and Safety
Store Sentinel tablets in their original packaging at room temperature (59–77°F / 15–25°C), in a dry place away from children and pets.
Because Sentinel is a prescription medication, it must be used only under the direction of a licensed veterinarian. Inform your vet about all other medications your dog is taking, as some drugs may interact with Sentinel.
Additional Recommendations
- All dogs in the household should be treated for flea control.
- Use concurrent adult flea treatments for quick relief, as Sentinel does not kill adult fleas.
- Practice good hygiene and clean up pet waste promptly to reduce environmental contamination.
Final Thoughts
Using Sentinel as directed—once every month and under a veterinarian’s supervision—can protect your beloved dog from serious and potentially life-threatening parasites. Its broad-spectrum protection and easy administration make it a trusted choice among pet owners and veterinarians alike.





