Sentinel Spectrum Chewable Tablets for Dogs, 50.1-100 lbs, 6 treatments

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Your furry friend must have a current heartworm test result on file with your veterinarian in order to be prescribed heartworm medication. Please visit your veterinarian to have this test performed annually to protect your four-legged friend. Sentinel Spectrum is a monthly oral preventive prescription that guards against heartworms, adult roundworms, adult hookworms, whipworms, and prevents the development of flea eggs. It protects your dog against heartworm disease and intestinal worms, all in a palatable, beef-flavored chewable.


Sentinel Spectrum is indicated for the prevention of heartworm disease. It is also formulated to help prevent and control flea populations, and for the treatment and control of adult roundworm, hookworm, whipworm, and tapeworm infections in dogs and puppies six weeks of age and older and weighing at least two pounds.

Possible Side Effects

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

Drug & Food Interactions

There are no known contraindications to the use of Sentinel Spectrum. 


Treatment with fewer than 6 monthly doses after the last exposure to mosquitoes may not provide complete heartworm prevention. Prior to administration of Sentinel Spectrum, dogs should be tested for existing heartworm infections. At the discretion of the veterinarian, infected dogs should be treated to remove adult heartworms. This medication is not effective against adult D. immitis. Mild, transient hypersensitivity reactions, such as labored breathing, vomiting, hypersalivation, and lethargy, have been noted in some dogs treated with milbemycin oxime carrying a high number of circulating microfilariae. These reactions are presumably caused by release of protein from dead or dying microfilariae. Do not use in puppies less than six weeks of age. Do not use in dogs or puppies less than two pounds of body weight. The safety of this medication has not been evaluated in dogs used for breeding or in lactating females. Studies have been performed with milbemycin oxime and lufenuron alone. Not for use in humans. Keep this and all drugs out of the reach of children.

  1. Prescribing Information

See all items by Sentinel Spectrum

  • Item Number
  • Brand

    Sentinel Spectrum

  • Dosage Measure

    Use according to your veterinarian's instructions.

  • Common Brand Name(s)

    Sentinel Spectrum

  • For Use With


  • Generic Name

    Milbemycin Oxime, Lufenuron, Praziquantel

  • Brand


  • Breed Size

    Medium Breeds, Large Breeds

  • Product Form

    Chewable Tablet

  • Health Condition

    Heartworms, Hookworms, Roundworms, Whipworms, Tapeworms, Fleas

  • Drug Type



Milbemycin Oxime, Lufenuron, Praziquantel n

Recommended Dosage

Sentinel Spectrum should be administered orally, once every month, at the minimum dosage of 0.23 mg/lb (0.5 mg/kg) milbemycin oxime, 4.55 mg/lb (10 mg/kg) lufenuron, and 2.28 mg/lb (5 mg/kg) praziquantel. For heartworm prevention,ngive once monthly for at least 6 months after exposure to mosquitoes.

Storage Instructions

Store in a dry place at controlled room temperature between 59° - 77°F.

SENTINEL SPECTRUM should be administered orally, once every month, at the minimum dosage. To ensure adequate absorption, always administer SENTINEL SPECTRUM to dogs immediately after or in conjunction with a normal meal. The chewables should be administered in a manner that encourages the dog to chew, rather than to swallow without chewing. Chewables may be broken into pieces and fed to dogs that normally swallow treats whole. Care should be taken that the dog consumes the complete dose, and treated animals should be observed a few minutes after administration to ensure that no part of the dose is lost or rejected. If it is suspected that any of the dose has been lost, redosing is recommended.

Heartworm Prevention: SENTINEL SPECTRUM should be administered at monthly intervals beginning within 1 month of the dog’s first seasonal exposure to mosquitoes and continuing until at least 6 months after the dog’s last seasonal exposure. SENTINEL SPECTRUM may be administered year-round without interruption. When switching from another heartworm preventative product to SENTINEL SPECTRUM, the first dose of SENTINEL SPECTRUM should be given within a month of the last dose of the former product.

Flea Treatment and Prevention: Treatment with SENTINEL SPECTRUM may begin at any time of the year, preferably starting one month before fleas become active and continuing monthly through the end of flea season. In areas where fleas are common year-round, monthly treatment with SENTINEL SPECTRUM should continue the entire year without interruption. To minimize the likelihood of flea reinfestation, it is important to treat all animals within a household with an approved flea protection product, as necessary.

Intestinal Nematode and Cestode Treatment and Control: Dogs may be exposed to and can become infected with roundworms, whipworms, hookworms, and tapeworms throughout the year, regardless of season or climate. Clients should be advised of appropriate measures to prevent reinfection of their dog with intestinal parasites. Because the prepatent period for E. multilocularis may be as short as 26 days, dogs treated at the labeled monthly intervals may become reinfected and shed eggs between treatments.


How are Sentinel Spectrum and Sentinel Flavor Tabs different from other heartworm medications?

Not all heartworm medicines provide the same spectrum of parasite protection. Sentinel Flavor Tabs are chewable tablets that protect dogs against fleas, heartworms, roundworms, hookworms, and whipworms. Sentinel Spectrum is a soft, beef and bacon flavored chew that adds tapeworm protection to offer the broadest coverage available.

My dog weighs more than 100 pounds. Are Sentinel Specturm or Sentinel Flavor Tabs a good option for him?

Yes. Talk to your veterinarian about the appropriate dose for your pet.

My dog is a toy breed. Are Sentinel Specturm or Sentinel Flavor Tabs okay for his small size?

Yes. Both Sentinel Specturm and Sentinel Flavor Tabs offer a size that can be given to small dogs. Sentinel Spectrum has a size available for dogs weighing from 2–8 lbs and Sentinel Flavor Tabs has a size available for dogs weighing from 2–10 lbs.

I see a few fleas on my dog. Is the medication working?

You may see an occasional “hitchhiker” adult flea that your dog has picked up at the dog park or in the yard or other infested environments where 95% of the flea population lives in the form of eggs, maggot-like larvae, and pupae. Sentinel Specturm and Sentinel Flavor Tabs put an end to fleas before they become adults. You may need an adulticide, such as Effitix Topical Solution for Dogs, to treat occasional adult fleas.

Can I give either Sentinel Spectrum or Sentinel Flavor Tabs to my cat?

No, both Sentinel Spectrum and Sentinel Flavor Tabs are only approved for use in dogs.

Customer Reviews
14 Reviews 14 Reviews 4.8 out of 5 Stars

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100% of reviewersrecommend this product

4.8 / 5

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  • Easy to order and easy to use

    By on

    We've purchased other items from Chewy and were always very satisfied so I decided to give their prescriptions a try. Once I ordered, Chewy contacted our vet and the Rx was renewed. Better price too. The product itself has worked well for Maverick. I just put the chew in with his food each month and he gobbles it up. No issues with fleas, heartworms or any other worms. No tick protection though.

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  • Heart worm Medicine Or Never Ending Taffy

    By on

    I finally got my product but this is legit the worst product ever my dog will not eat these. They are liver flavored which isn’t bad but it has to have the consistency of a never ending now and later or taffy. My dog is 65 lbs and chewed I kid you not no less then 15 times just on half the chew and then still spit it out. I read the reviews and should of headed advice but I said “my dog will eat anything”. Ha not these... stephanie

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  • Newy to Chewy

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    Even though I'm still using up (1 mo. left) my current medications for Mary, neither I or my vet see no reason that Sentinel won't work as well as the other two. Ordering was easy even though I had to send a copy of the prescription and telephonic communication was met with a friendly, knowledgeable, person. If you carry the products needed, I would recommend Chewy to others.

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  • Great item, but Chewy is now more expensive.

    By on

    We love this product and have used it for years, protect against the widest array of worms, fleas, and especially whipworm. Unfortunately, we can now get for less from our previous supplier.

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  • Great alternative for heart worm preventative medicine that can be chewable

    By on

    Bella easily eats the soft chewy pill- the other brands that she had to swallow were not tolerated.. even coated with peanut butter-

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  • Also Treats Whipworm

    By on

    Vet Tech phoned to tell me that my dog had 'whipworm'! (Sample taken to our appointment.) Shocker was that the Heartworm product that I had been getting from the Vet did not prevent/treat whipworm. So, why would I ever use that product again?

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  • Excellent treatment

    By on

    Have been using this product since 6 months old. Now 2.5 and never had any problem with fleas at all.

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  • Seems good

    By on

    Only used for one month so far but he ate it without a problem and did not seem to upset his belly unlike a similar more expensive product, trifexis. On trifexis he would have severe stomach upset and he hated the “chewy” tablet.

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  • Protection

    By on

    Effective and affordable heartworm and flea and tick protection for my service dog Buckey.

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  • So Easy to order...

    By on

    This was my first time using Chewy.com and it will definitely NOT be my last. The pills were less expensive and waiting for Dot the Dog at her front door in a timely manner! How easy was this?!

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