Sentinel For Dogs–Know Before You Buy

I decided to write a blog post answering some of the common questions I hear about Sentinel flea control medication for dogs. Sentinel is different from most other types of flea control products because it comes in the form of a pill rather than a liquid topical that is applied to your dog’s skin. The active ingredients in Sentinel, milbemycin oxime and lufenuron, are absorbed by your dog systemically and remain in the bloodstream for a period of around 30 days. Sentinel tablets should be given with a meal to ensure adequate absorption.

Sentinel for dogs is a chewable, beef-flavored tablet given once every 30 days to prevent heartworm infection as well as flea infestations. It can be given to dogs and puppies as long as they are older than 4 weeks and weigh more than 2 pounds. Studies showed no ill effects on puppies whose mother was given three times the normal dose of Sentinel while nursing and pregnant. However, you should consult with your veterinarian on whether or not giving Sentinel to pregnant or nursing dogs is recommended.

So, how does Sentinel work? Milbemycin oxime is the ingredient in Sentinel that prevents heartworm disease. You may have also heard of a product called Interceptor. The main ingredient in Interceptor is milbemycin oxime. The only thing that makes Sentinel different from Interceptor is that is also contains lufenuron, the ingredient used to control flea populations.

In addition, milbemycin oxime also aids in the prevention of infection against many intestinal parasites including hookworms, roundworms, and whipworms. Because of this additional protection against intestinal parasites many veterinarians recommend giving Interceptor or Sentinel to dogs year-round even though mosquitoes don’t pose a threat during certain cold months of the year. If you’re really into pharmacology, milbemycin oxime is classified as a macrocyclic anthelmintic. What this means is that it kills worms by interfering with their life cycle. The proper does for dogs is approximately 0.23 mg per pound of body weight.

Lufenuron is an insect development inhibitor. It prevents flea reproduction. Bascially, lufenuron is birth control medication for fleas. However, like birth control medication for people, it doesn’t kill the adult flea. When a female flea ingests a blood meal from a dog that has lufenuron running through his system, she gets her own small dose of lufenuron. This is deposited in her eggs which are unable to develop, mature, or hatch into adults. Sad for the fleas, but good for you and your dog. The proper dose of lufenuron is 4.55 mg per pound.

You may have heard of a product called Program. Program contains one single ingredient, lufenuron, and is used to prevent flea infestations. So if you’ve been paying attention, you’ve probably figured out by that Sentinel is simply the combination of two products, Program and Interceptor. It comes in four different sizes depending on the weight of your dog.

Brown 2 to 10 pounds
Green 11 to 25 pounds
Yellow 26 to 50 pounds
White 51 to 100 pounds

Dogs over 100 pounds will need to take two tablets of the appropriate size.

Now that you have the basics down, let’s start answering some questions:

1. Does Sentinel kill fleas?

No. Sentinel flavor tabs do not kill adult fleas. It prevents adult fleas from reproducing. So, if your dog picks up a flea or two at the dog park or during a walk, those fleas will be unable to reproduce. One of the things that makes dealing with fleas so frustrating is their ability to reproduce so quickly. Sentinel is a great product to use if your dog currently doesn’t have fleas and you’d like to keep it that way. Even if he does happen to pick up a flea or two, the problem will be a lot easier to handle.

And if you discover yourself with a big flea problem, Sentinel can also make life easier for you and your dog. The caveat is that you’ll need to use another product in combination with Sentinel to kill the adult fleas. Something like Frontline Plus or Capstar are good choices. Between the two I would probably choose Capstar, mostly because of its ability to work so quickly. Capstar contains an ingredient called nitenpyram which begins to work in 30 minutes. Within a period of 4-6 hours, 99% of adult fleas on your dog will be dead. However, Capstar only lasts for 24 hours so you’ll probably want to give one tablet to your dog every 3-4 days until adult fleas are no longer observed.

2. I gave my dog Sentinel but he still got fleas. What gives?

Sentinel flea medication doesn’t create an invisible force-field around your dog that magically repels fleas when they reach a certain distance. That would be like someone complaining that they got into a car accident even though they had their seat belt on. Fleas and accidents are still a part of the environment. If your dog comes into contact with other animals that have fleas or visits a flea-infested area, he may very well get fleas. However, these fleas will be unable to reproduce. If you’re worried, you can use another product like Capstar or Frontline until you no longer see adult fleas.

The bottom line is: if you see still fleas on your dog or puppy after giving Sentinel he is getting re-infected either from your house or his environment.

3. Does the flea have to bite my dog in order for Sentinel to work?

Yes. Sentinel is absorbed into the bloodstream. If your dog suffers from flea allergy dermatitis (an allergic skin reaction that occurs from flea bites) you should probably use a topical product like Frontline Plus for flea control. Revolution is a topical heartworm and flea control product but the medication is also absorbed into the bloodstream so that’s probably not a good choice either.

4. Can you get Sentinel for dogs without a prescription?

No. Because Sentinel flea control medication also contains milbemycin oxime, a heartworm preventative, you need to get a prescription from your veterinarian. Your dog will need to have a negative heartworm test before taking Sentinel. Reactions such as labored respiration, vomiting, salivation, and lethargy have occurred in heartworm positive dogs that have been given milbemycin oxime. These reactions are caused by the death and release of microfilariae (baby heartworms) living in the bloodstream.

5. Are there any side effects to be aware of?

As with any drug in human and veterinary medicine there is always the risk of side effects. The following adverse reactions have been reported in dogs after giving milbemycin oxime or lufenuron: vomiting, depression, lethargy, itchiness, hives, diarrhea, weight loss, poor coordination, seizures, hypersalivation, and weakness.

If any of these reactions occurred in our patients during my ten years working in veterinary medicine I haven’t been made aware of them. The only experience I have is one owner whose Basset Hound vomited up his Interceptor tablet after the first time they gave it when he was a puppy. However, we think the problem stemmed from an unsavory snack she stole from the garbage a short time before. She has not had an issue with the medication since.

If you’re concerned about the safety of Sentinel or think your dog may be experiencing a side effect from the medication you should contact your veterinarian.

6. Does Sentinel protect against ticks?

No. If your dog has a high risk of tick exposure you might want to consider using a product such as Frontline Plus or Revolution.

7. Does Sentinel kill tapeworms?

No. Even though Sentinel controls most of the intestinal parasites that dogs are susceptible to, it does not kill tapeworms. Dogs acquire tapeworms by either ingesting fleas (usually while biting at them) or ingesting an animal (rabbit, mouse, etc.) that has fleas. So, if your dog is infected with tapeworms flea control should definitely be a part of your veterinarian’s treatment plan. As far as I know, the only medication that kills tapeworms effectively is praziquantel which can be found in products such as Droncit, Drontal, and Drontal Plus. Don’t waste your money on over-the-counter worming medications since these medications only target certain stages of the worm’s life cycle and are ineffective. Praziquantel is the medication you need and it can only be purchased with a prescription.

In an indirect sort of way Sentinel may prevent tapeworm infection by decreasing the flea population but the active ingredients themselves do not physically affect tapeworms at all.

8. It seems strange that Sentinel doesn’t kill fleas. Can’t I just use Frontline Plus instead which kills adult fleas and prevents them from reproducing?

Yes, you can certainly choose to use Frontline Plus for flea control and a separate heartworm preventative such as Interceptor or Heartgard instead of Sentinel. However, many pet owners like the added convenience that Sentinel offers. Instead of dealing with two different products you only have to worry about one. It can be hard to remember what days to give the heartworm preventative and on top of that, you also have to keep track of when another dose of flea control is needed. Plus, if you’re dealing with an active flea infestation, you need to apply a dose of Frontline once every 30 days for 3 days to break the cycle. You might as well spend that money on Sentinel and a couple doses of Capstar!

Personally, I would rather give my dogs one pill monthly and be done with it. I usually find a flea or two on my dogs at least once during the summer months since they get to run around on our 3 acre property. However, because I know they’ve been getting Sentinel all along, I don’t sweat it. I usually just sqwish the fleas I find and that’s the last I see of them. I’ve never had to give them anything other than Sentinel. Although, if I did continue to see fleas I would give them Capstar once every 3-4 days until the fleas were gone. To me, giving a tablet is much easier than dealing with the liquid tubes, and the greasy mess associated with topical flea medications. But you should do whatever is most comfortable for you.

9. Sentinel seems expensive. Isn’t there a cheaper alternative?

It seems like a lot of people are on the lookout for cheap Sentinel flavor tabs for dogs. If you think about it though, what Sentinel costs you in dollars it makes up for by saving you time. Have you ever had to deal with a severe flea infestation? With “traditional” flea control products such as flea shampoos, flea dips, flea bombs, etc. you’re going to be investing an awful lot of time. Most of these products only target the adult stage so 30 days later you have to start all over when the larvae and pupae living in your dog’s environment develop and hatch into adult fleas. You have the vacuuming, the dipping, the combing . . . Ugh! It’s a vicious cycle than can easily drive a person bonkers. Over the counter flea products are both less effective and more dangerous to your dog. Sentinel is expensive, but remember–it contains both a heartworm preventative and a flea control product in one tablet.

Well, I hope that covers most of the questions you had about Sentinel flea control medication for dogs. I know some people who don’t care much for the product mostly because it doesn’t kill adult fleas. However, I don’t think that’s such a big problem as long as you’re prepared for the fact that you still might find fleas on your dog. However, if you do, it will only be temporary. I think a lot of people who complain about Sentinel are those that weren’t aware before buying the product that it doesn’t kill adult fleas on contact. It’s what I’ve been giving my dogs for the past few years, and I’ve been very happy with the results.

If you have any additional questions which I didn’t address, please leave them in the comments below. Thanks!

References: Sentinel Product Insert NADA #141-084 Approved by the FDA

Amanda is a 2-Star Diamond Beachbody Coach, retired Licensed Veterinary Technician and RRCA certified running coach. Her geekiness is legendary and is most proud of the fact she finally found a way to turn her passions for running, fitness, nutrition, writing, and pets into a full-time business that now helps others get off the couch and get after their dreams. Proverbs 3:5-6


  1. sharon says

    My golden retreiver has suffered seizures on sentinl, i stopped the sentinel and tried heartguard, 2 days after giving her heartguard she threw up and within 6 days she had a seizure. i havent given any heart worm medication in 2 months and no seizures, what is a safer heartworm medication i can give my pet.

  2. says

    Hi Sharon–I’m sorry to hear about your dog’s seizures. This is a problem that you really need to discuss with your veterinarian. I know you only want to do the right thing but just like humans no two dogs are the same so it’s impossible to say that one heartworm medication is “safer” than another. There is another medication called selamectin (Revolution) but I would definitely talk to your veterinarian about it.

  3. Nancy in California says

    Hi, Amanda! Great article on Sentinel! You answered my questions perfectly! Thank you! Sincerely, Nancy :o)

  4. Kelly says

    How long does it take for the medication to be adequately absorbed? My dog vomitted several hours after taking the tablet and I wonder if I should re-dose. He’s never had this problem before so I’m not concerned that it was a bad reaction, I just want to make sure he’s benefitting from the dose. Thank you

  5. says

    Hi Kelly, if it was just a few hours I probably would give another dose–that’s what I would do if it was my dog. But you might want to ask your veterinarian to make sure.

  6. Emma Ramshaw says

    Thank you so much for this informative article.
    I just wanted to check something with you. My dog has a severe reaction to Frontline or any topical flea treatment. Our vet seems to think he is allergic to the alcohol. He has severe allergies to pretty much everything, and is currently having treatment for severe itchy skin, probably dermatitis. I haven’t found any fleas on him what so ever, but obviously am concerned that it might be a rogue flea or two causing the problem. He is on a limited ingredient diet and tends to react badly to pretty much everything he eats, and most medication in pill form. Do you think Sentinel might work for him?

  7. says

    Hi Emma, thanks for your nice comments. My only concern for you and your special pooch is that in order for Sentinel to work the flea has to bite your dog. This is because the medication circulates in the bloodstream, unlike topical treatments which remain on the skin. If your dog is extra-sensitive this might not be the best scenario, although it would definitely prevent a potential flea problem from getting worse. I would be curious to know what your veterinarian thinks about the idea.

  8. Tami says

    My new vet prescribed Sentinel for my dog and I had previously been using Advantage Multi. The main difference between the two products seems to be that Advantage Multi kills the adult fleas, whereas Sentinel make the fleas unable to reproduce. Here is my issue: I have cats in my household who do not go outdoors, are not on heartworm or flea preventative and have not in 10+ years had any flea issues. I am worried that on Sentinel my dog could bring fleas into the house and then they could get on my cats since the fleas are not being killed by the Sentinel. I understand that they won’t reproduce but I don’t want fleas hanging around and biting my cats and family either. Your thoughts?

  9. says

    Hi Tami, my household sounds a lot like yours. I have two dogs and five cats. My cats don’t go outside either. I’ve had my dogs and cats for 9 years now and (knock on wood) I’ve never had to use any flea products on my cats.

    I found a flea on my dog Maggie on two different occasions (we live on 3 acres). Both times I spotted the flea as soon as she came inside and I killed it. Both times I never saw another flea after that. It really depends on your dog’s lifestyle . . . if he is at high risk for picking up fleas (running around dog parks, hanging out with other dogs, running through the woods/grass) you might want to stick with a topical product, otherwise Sentinel will probably be fine.

    On the rare occasion that you might get a flea inside your home, chances are it will stick with your dog because once fleas find a host and a bloodmeal they stick with it.

    Yes, you might run into a flea or two with Sentinel but really–that can happen with any flea product. However, I tend to trust Sentinel a little more than topical products because I know that one flea won’t turn into hundreds of eggs and pupae.

  10. Christy says

    Thanks for the article. A friend of mine told me that Sentinel can cause severe liver failure. Her dog went on it and by the second dose passed away due to liver failure per the autopsy…they would not specifically state it was due to the medication but hinted at it. Is this a true side effect? Should I switch my pug back to Interceptor? She has been on the Sentinel for around 9 months and I have not noticed any issues but I definitely do not want to put her at risk just to sterilze pesky fleas.

  11. says

    Hi Christy, I’m sorry to hear about your friend’s dog. Sentinel is not unlike any other medication in that there is always the potential for side effects. Even so-called “natural” and herbal remedies have the potential to do harm if a pet is susceptible.

    It sounds like your friend’s dog may have been very sensitive or perhaps even pre-disposed to liver failure due to a genetic condition. Perhaps one of the active ingredients in Sentinel just pushed him over the edge into liver failure. During my years in practice I have never heard of or seen a dog die suddenly after taking the medication.

    If you’re concerned about potential problems I would recommend having a blood panel done on your pug. That’s really the only way to know for sure what’s going on inside your dog’s body.

  12. sue walsh says

    We just moved from PA to NC and our new vet recommended Sentinel for our dachshund. I am concerned about tick protection for her when we visit PA which has a high level of tick infestation. She was on heartgard and frontline in Pa and I’m concerned about ticks in NC as well. Would it be OK to give her Frontline along with the Sentinel?

  13. says

    Hi Sue,

    Yes, you can give Frontline along with Sentinel. Frontline is not absorbed systemically (into the bloodstream) like Sentinel. However, this probably won’t be very cost effective for you. I would express your concerns with your new veterinarian. They might recommended giving Interceptor instead of Sentinel.

  14. mary anne says

    I especialy enjoyed your article on Sentinal, but I have a question. I use Heartguard plus for my dogs (age 12 and 4) but do not usually use a flea and tick product as I have problems using a systemic pesticide on my animals. I have always given them brewers yeast and garlic and never(knock on wood) had a flea or tick problem. Do you have any advice or scientific information that might change my mind and help me consider Sentinel?

  15. says

    Hi Mary Anne, there is lots of scientific information out there about fleas and flea products. One guy that probably knows more about fleas than anyone else (he’s called the Flea Doctor)is Dr. Dryden from Kansas State. On the bottom of the page you will find links to many of his research articles.

    I also trust the opinion of Dr. Narda Robinson from Colorado State. She specializes in complementary/alternative medicine. You might find this article interesting:

    What flea products you choose to use on your pets is a personal decision. A good place to research anything is PubMed. Just type your term or product (active ingredient) in the search box.

  16. patricia hecker says

    I have a shihtzu puppy,she is almost 4 mos old.She has had two doses of Sentinel,and been wormed per the vet 3 times,even though she tested negative.This is a new vet and she is having slight head tremors.I have been reading the side effects of Sentinel,she is very small at 4 pounds,I don’t feel confident in taking her back,please advise.

  17. says

    Hi Patricia, you might want to consider getting a second opinion from another veterinarian in your area if you don’t feel right going back to the original doctor. Sometimes too, puppies will shake just because they’re nervous. I can understand why you might be concerned with such a little one. I’ve never seen any puppies or dogs have a reaction to Sentinel, but it’s always a possibility. You might want to consider seeing a doctor that specializes in neurology. As a young puppy, it’s possible that there may be some genetic defect or developmental problem that’s causing the tremors, not a side effect from the medication. Please let us know what you find out . . .

  18. Donna says

    I was using Heartgard for years and this new vet requested that I try Sentinel. My little guy doesn’t like it. It is a chore to make him take it and it doesn’t get rid of fleas. I have decided to go back to Heartgard which is easier to use and Frontline Plus. It seems to work best especially since it isn’t healthy to use Sentinel and Frontline Plus, right?

  19. says

    Hi Donna, yes, Sentinel is beef-flavored but some dogs still won’t eat it. This is especially true if the dog is used to Heartgard which contains the doggie equivalent of high-fructose corn syrup. You might have already tried this, but hiding the tablet in a small amount of peanut butter, cream cheese, or hot dog might help. No, Sentinel does not kill adult fleas but it prevents them from reproducing which is 95% of the battle. It is perfectly fine to use both Sentinel and Frontline Plus together but that would be pretty expensive. A better combination is Sentinel and Capstar.

  20. marcia rea says

    Thanks for this article. I’m really hesitant to use any flea/tick/heartworm products because of all the horror stories I’ve heard. Your article is clear and understandable and answered all my questions without being condescending. thanks so much

  21. says

    Hi Marcia, I’m glad I was able to answer all your questions. Yes, you will definitely hear lots of horror stories, esp. if you spend any amount of time on the internet. Honestly, the only horror stories I’ve ever encountered during my 10+ years as a vet tech are the result of owners using OTC flea products like Hartz, Biospot, etc. . . that’s a pretty good track record for all the other products, in my opinion.

  22. karen says


    My 5 year old has been on sentinel for over 3-1/2 years and has never missed one month’s dosage. My vet’s office is now requiring me to have him tested every year in order to get a new prescription. If I do not miss a dosage and this is suppose to prevent heartworm, why does he need to be tested every year? Is this a way to provide additional income to the practice at the expense of loving pet owners?

  23. says

    Hi Karen, there’s a couple reasons why vets recommend annual testing even though your dog is on heartworm preventative year-round.

    First, no medication is 100% effective. There is not a doctor in the world that will tell you that birth control pills are 100% effective. There is also not a veterinarian in the world that will tell you that heartworm preventative is 100% effective. I know of a veterinarian technician whose dog showed up heartworm positive after faithfully giving him his heartworm pills. Think she was suprised? Yep. :-)

    Second, the manufacturer will only guarantee the product if the dog is tested yearly. If for some reason your dog comes up positive, they will pay for treatment, every single dime. If you don’t test yearly, or only test ever other year, etc. you will be responsible for the costs of treatment.

    Certainly, you shouldn’t be forced to do something you don’t want to do . . . if there is an owner at our practice who doesn’t want to test, we have them sign a waiver. Not sure if that’s an option at your vet clinic. I can understand why you feel the practice is out to make money, but they are only practicing good medicine.

  24. karen says

    Thanks Amanda. I wish that information would have been provided to me when I was told that he needed to be tested – I had no idea about the mfg paying if the dog is tested positive.

  25. says

    You’re welcome Karen, I know a lot of per owners aren’t told that. The same is true if the medication is purchased online . . . the manufacturer will only stand behind their product if it’s purchased directly from the veterinarian.

  26. Mary says

    Hi Amanda,
    I too am located in Michigan and have been giving my mini doxie Sentinel for the last couple of years. She will not take it directly, as a treat, but will, when it is in her kibble and considering it is recommended to be given with food, it has worked out well for us. We have been quite pleased and thank goodness have seen no ill effects. However, her vet has stopped selling Sentinel and I was only able to get enough to last until September (she is treated year round and gets annual heartworm tests). Any suggestions, since I really like her vet and do not want to have to change (he has been seeing her since she was 4 months old and is now 4 years old).
    Thanks much for your time!

  27. says

    Hi Mary, your current vet should have no problems writing you a prescription for Sentinel, esp. if they decided to stop selling it. Just explain that you have been really happy with the product and they should accommodate your request with no problem. There are a couple of options . . . you can purchase Sentinel from another vet in your area that sells it. You don’t have to change vets, the other clinic will just need to see documentation (usually a receipt is fine) that your doxie’s heartworm test is up to date. You will probably just have to make some phone calls. We do this all the time where I work. The other option is to purchase your Sentinel from an online retailer like PetMeds or Foster’s and Smith. Their prices will probably be cheaper, but keep in mind that the manufacturer will not guarantee the product (pay for heartworm treatment if your dog tests positive) if you purchase from an online retailer. Also, some of these online products have been shown to be counterfeit.

  28. Mary says

    Thanks much Amanda, appreciate the advice. I will be calling around to see if any of the other local vets are carrying Sentinel. Have a nice evening!

  29. Mary says

    Hi Amanda-
    I have a 4 pound, 3-month-old bichon frisé/toy poodle mix puppy. After he was started on Sentinel last month I found several fleas on him. I purched Frontline Plus at PetSmart and two weeks later I found more fleas. I went to my vet for advice and they suggested keeping him on Sentinel and giving him Revolution, since they have found that our local fleas are having some resistance to Frontline Plus (I live in south Louisiana). My question is: is it OK since BOTH products contain medication for heartworm prevention? They didn’t seem to think it was a problem, but I certainly don’t want to overmedicate him & cause him more harm than good. I asked about Capstar but they didn’t think it was a good idea since it only lasts for 24 hours. Thanks for your advice.

  30. says

    Hi Mary, if that’s what they’re recommending it’s probably OK. Chances are he will only need the Revolution for 3-4 months anyway. Heartworm medication is given in extremely high doses during product testing with only a small population of dogs having a problem. Just remember to give Sentinel with a meal because sometimes not doing so will limit the effectiveness of lufenuron (the active ingredient that controls fleas). That being said, I would agree that the *best case* scenario would be to give only one medication for heartworm prevention if possible. The other option is to give him Program (which only contains lufuneron) along with the Revolution and then save your Sentinel for the winter months. If your vet doesn’t sell Program I would ask them where they recommend you purchase it from. You may need to purchase it from another vet in your area. DO NOT BUY PROGRAM FROM A PET STORE. Lufenuron is one of the best medications for keeping flea populations under control, so you definitely want to keep that in the equation.

  31. Kim says

    Hi – I had my cockapoo on Revolution. She progressively developed side effects after every dose – vomiting, diarrhea, lethargy, panting,etc. I switched her to Sentinal. For the first two months she had no apparent issues. This month she had violent diarrhea in the middle of the night about 7hr after receiving Sentinal, and 48hrs later she is vomiting. I feel like these meds are poisoning my dog.

  32. says

    Hi Kim, that’s something you should definitely talk to your veterinarian about. Heartworm medication is just like any other prescription medication. Some dogs are just more sensitive than others and unfortunately your dog may be one of them. :-(

  33. Kevin says


    I took my 9 week old Lab Mix in for his first puppy check, was told he was healthy, given wormer per normal and one small brown “perfectly safe” Interceptor Flavor Tab was told to give it to him on a day of my choosing, and all would be well, He was given the pill Monday August 20th 9:00pm that night we experianced reverse sneezing, tuesday he seemed to be breathing kind of fast, but not panting, or anything he played ate, and slept, wednesday 3:00 Pm extreme rapid breathing, rushed to vet, arrived unresponsive, and life saving measures were unsuccessful. I am awaiting the results of a necropsy on my dear sweet boy I am heart broken, and since the the circumstances of his all too short life left him no opportunity to get into anything. I am left to believe the pesticide killed my poor dog.

  34. says

    Hi Kevin, I’m SO sorry to hear about your loss. It sounds like he may have had an allergic reaction? Unfortunately the world is full of allergens for pets and people and certainly some allergens are worse than others including things that seem harmless like peanut butter, bee stings, medications, etc. Please let us know what you learn from the necropsy. Hopefully your veterinarian is being supportive.

  35. Kevin says

    The vet was not being supportive until I research Interceptor with the FDA and according to the most recent plain english facts from 2007 Interceptor was killing 13 healthy dogs a year. Not to mention the 4877 other ADE’s filed compliled of 150 other complaints. many minor many needing life saving or resusictation measures. I insisted that an ADE be filed then got some support, other than that, it was so sorry about your puppy haveing congestive heart failure, a week after we told you he was in perfect health.

    FDA FACTS: That Novartis doesn’t want vets telling people, and that Novartis doesn’t tell vets….
    Milbemycin, Oral, Dog (Interceptor™ brand name) Year approved; 1995
    ADE Reports in FDA through 7 June 2007: 4,745 (395/yr)
    Total Deaths: 159 (13/yr); Convulsions: 268; Anemia: 29; autoimmune hem: 15; Platelets low: 1
    Reports of ineffectiveness against heartworm (total): 2757
    Ineffective against heartworm reports per year: 230

    Please remember that I got this infor off the FDA foa website.
    Secondly: many Vetrinary Professionals believe that only a small number of the actual problems and deaths from this pesticide are actually reported, due to the animal acts funny for a day or two and recovers, or dies and the vet says oh your poor dog had heart failure and people leave it at that, this is just like any other medical nightmare, big money says there are an acceptable number of deaths from our product, and untill someone says we need to warn people about that we are not going to.

  36. Kevin says

    The really great part of all this was… I asked, in plain simple English is this safe for my puppy? Do I need to watch out for anything? Isn’t he too little to worry about starting this? I was told, by the Vet Tech and the DVM attending, “Yep perfectly safe, little brown beef flavor pill.” Don’t worry about it. I was given one tablet in a foil pop out package labled “Keep out of reach of children and animals, wash hands thoroughly after giving.”

  37. Marie says

    Thanks for the info. My two dogs have been on sentinel for a while now. I recently visited my grandparents who also have two dogs. They have had a flea problem for a while now, I thought it was taken care of because it has been so long, but I guess that’s what happens when you assume something. I luckily have not found any fleas on my dogs but I have bites everywhere on my body! I have been vacuuming, washing my bed spread and clothes constantly, taking long baths in HOT water with lots of soap, ect. Do you know of any other way for me to get rid of this flea problem on myself???

  38. Marie says

    By the way, my dogs will not take the “flavor tablets” on their own either. I just pry open their mouths and drop it in the back of their throats. I have tried putting them in treats, hot dogs, cheese, but they somehow eat the treat and spit out the pill!

  39. Eli says

    My 2 year shih tzu has been taking sentinel for over a year. He has never had any problems on the medication. My vet started him on the medication after his first visit as a small puppy. The pill did it’s job, but he would often get fleas on him after visiting relatives. I spoke with my vet about it an they put him on Sentinel and also comfortis. At the time I felt like this was a lot of medicine for my little guy. Then the vet clinic started selling Advantage multi (I believe)and suggested I try this to see if it was a better match for my dog. We tried that for 3 months until I realized that I was allergic to something in the liquid and I would break out whenever I put it on him. So, after a few months we went back to the Sentinel and Comfortis. My vet clinic seems to think this is ok. It is a little bit expensive, but everytime I take him off the Comfortis he seems to get fleas on him again. Would you say this is a good combination? I do not want to overmedicate him and of course I want him to be healthy and happy. What are you suggestions?

  40. says

    Hi Eli, your veterinarian would not recommend something that he/she would think to be harmful. If the combination seems to be keeping the fleas at bay then I would stick with it. Each dog is different.

  41. Sam says

    Hi Amanda. I enjoyed reading your blog and the comments/responses. I have a 4 1/2 year old neutered male APBT — Brutus. We’ve had Brutus for 1 1/2 years, and started him on Revolution as soon as we got him. I walk him daily, on-leash only, for 3+ miles/day, unless the weather is too extreme. (We live in Maryland, and I’d say I’m able to walk him 340 or more days out of the year.) I’ve never seen a flea on him, and his yearly heart worm tests have been negative. (He has minimal dog-to-dog contact in that he’s never taken to any dog parks, but he does have some contact when we’re out for walks when he meets the regular neighborhood dogs that are either in their yards or else being walked by their owners. We also have a resident deer population that sometimes walks through the back yards of the houses here in suburban Baltimore County.)

    The problem is…the past 3 times I’ve applied Revolution he has bolted as soon as the medication hit his skin. The last time I had to attach a leash in order to keep him close. It took 3 different attempts to make sure the entire vial got applied. There’s no irritation at the site, but it seems as if he’s reacting to the alcohol in the Revolution product. I tried an experiment in which I put water in an eye dropper, and applied it as if it were the medication. He had no reaction. It’s definitely something in the Revolution product that’s bothering him.

    I Googled, and decided that Sentinel would be the best alternative to the Revolution product. (I’ve got a call in to my vet as we speak to get her feelings, but in the meantime I saw this blog and wanted to post/ask a question.) The question I have is this: I read about Capstar, which is often used in conjunction with Sentinel. I also found a spray-on product called Mycodex Sensicare Flea & Tick Spray. It’s used to kill adult fleas and ticks, and is a water based product that contains no alcohol. It’s made for pets who are sensitive to alcohol based products, and unlike Capstar, it also works on ticks. I don’t know if the Mycodex product is an OTC or something that requires a prescription, but I ordered it from Amazon and it did not require any vet authorization. What are your thoughts as far as Sentinel + Capstar vs Sentinel + Mycodex Sensicare?

  42. says

    Hi Sam, you do not need to give Brutus any Capstar unless you see adult fleas. Sentinel alone should be fine for him. Even if he does pick up a random flea from somewhere that flea will be unable to reproduce if you keep him on Sentinel. If you are mainly taking him out for walks I would not worry about ticks too much. I would be hesitant to use any type of OTC flea/tick product. Many contain pyrethrins which not only are ineffective when it comes to controling fleas, it can also be toxic to both dogs and cats. Unless the flea medication also includes an ingredient for heartworm prevention you will not need a prescription. My vote for Brutus is Sentinel. I hope that helps! Please let me know what your vet says. :-)

  43. Sam says

    Hi again, Amanda. I just got off the phone with the vet. She stated that she is not a big fan of Sentinel (because it offers no tick protection and doesn’t kill adult fleas), so she wants to try a one month trial of Frontline Plus and Interceptor, to see if Brutus tolerates the Frontline Plus better than Revolution. I asked some questions, and tried to steer the final decision towards Sentinel, but in the end I agreed to try the Frontline Plus/Interceptor combo for at least one month. It’s possible that he’ll tolerate Frontline Plus better than Revolution, but I have my doubts. I also was not thrilled about the fact that it takes Frontline Plus up to 2 days to completely dry, whereas Revolution was dry to the touch in about 2 hours. (He has a very short coat and even with the Revolution it basically just ran down his back, rather than stay in one spot. It was kind of a hassle.) Oh well…I’ll see what happens on March 1 (that’s when I would have given him his monthly dose of Revolution, and that’s when I’ll give the Frontline Plus/Interceptor combo.) I’ll report back then with an update. Thanks again for your blog and your timely response.

  44. Scott says

    Hey Amanda,

    I have a 4.5 year old greyhound and my vet recommended giving him sentinel, however I have heard from other grey owners who use it that they break the tabs in half and that does the trick because greys are so sensitive to medication, have you ever heard of this?

  45. says

    Scott, it’s not something I would recommend doing. The medication is based on weight. If you give your dog half a tablet it might not be enough protection if he does get exposed to an infected mosquito. There is also no way of knowing how well the active ingredients are distributed. You may give him half a tablet but all the active ingredients are in the other half of the tablet. I have not heard that greyhounds are more sensitive to this type of medication.