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Heartgard and Frontline, Sentinel and Nexgard, or another combo for flea and heartworm prevention?

3721 Views 12 Replies 8 Participants Last post by  stbob
I'm taking a deeper look at the current flea/heartworm protection options for dogs. I've already read posts about it, but my questions are a little different.

I volunteer with a small foster-based dog rescue group in an area where both flea and heartworm protection are necessary except in the winter. Because the group has only a few dogs at a time and we don't know the size of the dogs that will be with us next, we have to buy a 3-6-month supply of flea and heartworm protection for each dog. The group isn't limited to any particular size or breed, but dogs that come to us tend to be medium to large, which increases the cost.

Like any rescue group, we have to be careful with money, but health and safety come first. Also, because we have to buy supplies for each dog, we need options that adopters will be comfortable continuing.

Personally, both flea and heartworm prevention drugs make me nervous because they aren't good for dogs and can have serious side effects. However, fleas and heartworms aren't good for dogs either. My approach is find out (if I can) which ones are the safest and to give them only as often as necessary (not year round in the climate I live in). I'm still reading to try to figure out which ones have the least risk and are still effective.

A challenge is in finding a combination that does what it needs to do and not more, to avoid unnecessarily overmedicating dogs.

Based on the above, which combinations would you prefer or avoid and why?

Heartgard (kills heartworms, roundworms, and hookworms) and Frontline Plus (kills fleas, flea eggs, and larvae, kills fleas that come in contact with the dog without the flea having to bite the dog first; kills but doesn't repel ticks; repels mosquitoes; kills chewing lice)

This option costs less than the option below, and it works for most needs. A disadvantage is that Frontline makes the dog's coat feel sort of sticky, at least for a few days.

Sentinel Spectrum (kills heartworms; treats and controls adult stages of tapeworms, hookworms, roundworms and whipworm; prevents flea eggs from hatching) and Nexgard (kills fleas, flea eggs, and larvae, but doesn't repel mosquitoes; kills but doesn't repel ticks)

This option is more expensive. Fleas have to bite the dog to be killed, and it doesn't repel mosquitoes. However, it provides protection against more types of worms, and it doesn't leave the dog's coat sticky.

Any other combinations?

Thanks for your help. :)
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I will just give you the combination that I use, which is very similar to your 'option 1', for your consideration. As I am in NC, I do treat year round.

I use Frontline Plus for flea/tick. (While I know many people say that this is no longer 'effective' in their location, I personally have not experienced that. Perhaps it's because I live in a very rural area, and the fleas & ticks don't get exposed to enough of it to develop any sort of resistance?) I like the fact that ticks don't have to bite in order to be killed. We really don't have a flea problem (never actually seen one), but 10 wooded acres lend itself to being a 'tick farm'. In the 11 years I've lived here, with either 3 or 4 dogs the entire time, I have only had to remove 4 or 5 ticks total that had attached to a dog. So, that's my endorsement for FL+. (I do admit to not liking the oily spot on their back the day after treatment, but I apply it at bedtime & usually in 24 hours it's gone)

Rather than Heartgard, I use Interceptor for heartworm. It also controls round, hook & whip worm. There is also an Interceptor + that adds praziquantel to cover tape worms as well (I don't bother with that one because, as I already mentioned, fleas aren't a problem for us) Because it's not ivermectin based, I don't have to worry about any possibility of MDR1 sensitivity.

So, there's my 2 cents.
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Disclaimer in that I've only ever had to deal with preventative meds for my personal dogs, not a rescue/foster situation, but I do have a couple thoughts.

My first would be to check with the vet you use in case they have some insight into what options are most effective in your local area. There do seem to be areas where local flea/tick populations aren't as responsive to certain preventatives as they should be, so if your vet has noticed such a pattern in your area it'd be important to know (this is not the case for heartworm medications, as far as I know).

My second thought is do your foster homes also have cats in the household? Certain dog flea/tick medication isn't safe for cats (and other small pets) to be in contact with, even though they're totally safe for dogs and humans. So if you have mixed-species households fostering, you may want to keep that in mind. I believe Frontline and Nexguard are both cat-safe but I thought I'd bring it up just in case it does come up.

I did Heartguard and Frontline for a few years with my poodle, and was very satisfied. I had a single tapeworm incident where I bought the appropriate wormer OTC when I noticed symptoms and it cleared up quickly. I'd pull a few ticks off him every year, but we had a LOT of ticks and they never reached that super bloated stage where they'd clearly been attached for a while - if I found them attached they never looked like they'd been on long. You'd likely need more if you're treating an already infested animal, like Capster, topical flea shampoos, etc., but as a preventative it worked for me.

It's worth noting you should never start a dog on heartworm preventative without a veterinary examination and prescription, because giving a HW+ dog a preventative runs the risk of causing their HW load to die off suddenly and seriously damage the heart or even kill the dog. For this reason you really can't be keeping HW meds 'on hand'. It's also why you shouldn't really be only using it seasonally - it's a way more serious infection than most worms/parasites and really should be treated with caution.
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My personal preference is an ivermectin/pyrantal based heartworm preventative (Heartard Plus, Tri-Heart Plus, etc.), and Nexgard for fleas on an as-needed basis.

The ivermectin/pyrantal heartworm meds have been around a long time (thirty-odd years now?), with proven overall safety and efficacy. Frontline works well for a lot of dogs, but I've found that flesas in my area area seem to be developing a resistance to it. While a lot of people like the convenience of "one pill for everything", and have great success with it, other people prefer to separate things out.

Perhaps you could work things out with your vet to buy in bulk, in order to have supplies on hand to give once the dogs have been tested for heartworm, instead of having to buy them for each individual dog?
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I would do HW tests on all incoming dogs and then get them on Tri Heart with a 6 months supply. Wrap the costs of the pills into the adoption fee and treat it as a convenience to the adopters to be able to seamlessly continue the same HW meds while getting settled.

Properly dosed commercial HW meds have almost zero MDR1 risk. Ivermectin is not the only drug on the MDR1 sensitive list anyways.

If the dog is potentially around cats, use a cat safe topical flea treatment but since those are over the counter, its easy to buy a box of Frontline in both medium and large. I use Advantix2 for flea and tick and think its better than Frontline but it is not cat safe

One option that requires much carefulness is getting a HW test and then buying ivermectin from farm supply and dosing with an oral syringe. Not the best option and has risks with overdose and MDR1 sensitive dogs but its a known option for extreme budgets in high HW risk areas. This would require the adopters to get a new HW test before getting meds from their own vet.
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Thanks, everyone.

After researching the options, I narrowed it down:
  • Flea/tick: Frontline or Nexgard
  • Heartworm: Tri-Heart Plus or Interceptor Plus
All the options have advantages and disadvantages.

For fleas and ticks, we went with Frontline. I asked in a local pet group if it still worked for them, and it does. It's always worked when I used it on dogs too. I like the fact that fleas don't have to bite the animal to die.

Nexgard might have a higher rate of bad reactions, but I didn't count posts about it. That was just my impression. However, it's a good choice for families with small children -- you don't need to keep them away from the dog while the insectide is spreading. For the same reason, I can see it as a good choice for households with more than one dog or with dogs and cats that snuggle together. Since those aren't factors for us, I went with the less expensive option.

For heartworm medication, the choice was pay less and get less or pay more and get more. Here's what the options I looked at and what they protect against, in ascending order of price:
  • Tri-Heart Plus (heartworms, roundworms, hookworms)
  • Iverhart Max (heartworms, roundworms, hookworms, and tapeworms) (it has a lot of bad reviews about the "soft chews" being too hard for dogs to eat, so it's off my list)
  • Interceptor Plus (heartworms, adult roundworms, adult hookworms, adult whipworms, and adult tapeworms)
  • Heartgard (heartworms, roundworms, hookworms)
  • Sentinel (heartworms, adult roundworms, adult hookworms, whipworms, and prevents the development of flea eggs)
They all had good reviews for effectiveness.

Tri-Heart Plus and Heartgard are exactly the same except that Heartgard costs a lot more. I'm not interested in paying more than I need to.

Both of the flea/tick prevention options I narrowed my list down to prevent the development of flea eggs. Since Sentinel also does that, using it with either Frontline or Nexgard would mean giving the animal a double dose of insecticide for that purpose. As with any medication, we should use or give only as much as is necessary. So, Sentinel is off my list.

That leaves us with Tri-Heart Plus and Interceptor Plus.

I decided that it was worth it to pay a little more to get a little more as Interceptor Plus protects against more types of worms than Tri-Heart Plus does. So, my heartworm prevention choice is Interceptor Plus

I hope all this helps some people decide which options to choose for their dogs.
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^^^ It helps me. We've been using Heartguard and she considers it as a treat, but I'll look into Tr-iHeart and Interceptor Plus if cheaper.
We tried Nexgard for flees and ticks but our dog threw up within minutes. We now use Frontline, but I wish there was a chewable that worked for her.
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Little late to the game here (sorry). We used to use Frontline as tick preventative, and it worked just fine for us. Only downfall was the greasy spot left after application. I also liked that I didn't have to buy it at the vet, I could actually purchase at Costco for cheaper. Still expensive stuff, but not as expensive as other stores!

At our last checkup the vet suggested Simparica Trio as a combination heart worm/all other worm/flea/tick preventative. She said more and more of her patients were saying that Frontline was no longer working for tick prevention. What I was using previously worked fine, but I really liked the idea of "one pill for everything" preventative. For a twelve month supply, the cost was a little over $300, but I purchased through my vet because I'm too lazy to look for better deals at other pharmacies. My vet bill was pretty much the same as previous checkup visits, and I save money because I don't have to purchase Frontline!

I can confirm the tick killing portion works, because I recently found a dead tick stuck to Ralphie's skin, which is super odd for North Dakota...Ticks don't usually come out until late May/June here!
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Little late to the game here (sorry). We used to use Frontline as tick preventative, and it worked just fine for us. Only downfall was the greasy spot left after application.
And that is now a problem, one that is making me rethink my Frontline choice. I applied it at 9am this morning, and she has a play date at 5:30pm, but the spot is still there between her shoulder blades. How long do I need to wait after applying it for a play date to avoid putting the other dog at risk?

Those of who who have more than one dog and use a topical flea treatment, how long do you keep playful dogs apart? I've already rescheduled the play date once, and I'm wondering if I should reschedule it again.

(Without making this longer with unnecessary details, I'll just say that today was the day I needed to apply Frontline.)

At our last checkup the vet suggested Simparica Trio as a combination heart worm/all other worm/flea/tick preventative. She said more and more of her patients were saying that Frontline was no longer working for tick prevention. What I was using previously worked fine, but I really liked the idea of "one pill for everything" preventative.
Personally, I don't like the all-in-one options as they put a heavier load on the dog's immune system all at once. I'd rather be able to spread it out. Also, if the dog reacts to it, you can't know whether it's the heartworm or the flea treatment. But we each have our own preferences.
I don't let the other dog like, actively lick the spot where the topical was applied, but as far as I know there isn't much risk unless you know the other dog has had severe/allergic reactions to topical flea meds in the past. Since mine are both fine with topicals I've never separated them after application. Obligatory 'I am not a vet' but I wouldn't be overly concerned based on my experience.
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I always apply my Frontline right before bed so it has a full 8 hours or more to soak in before the dogs are back in close contact with each other again. Yes, the oily spot is still there in the morning, but usually by noon or so it's pretty much gone. When my Abby & Charlie were young, they did a whole lot of wild wrestling which included mouthing & neck grabbing, so I typically kept their play lower key for that entire day, just to be safe.
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I always apply my Frontline right before bed so it has a full 8 hours or more to soak in before the dogs are back in close contact with each other again. Yes, the oily spot is still there in the morning, but usually by noon or so it's pretty much gone. When my Abby & Charlie were young, they did a whole lot of wild wrestling which included mouthing & neck grabbing, so I typically kept their play lower key for that entire day, just to be safe.
Thanks. This dog is a foster dog, and it's the first time I used Frontline on her, so I had to make sure it was at a time when I could keep an eye on her in case she had a bad reaction to it. She's doing fine, so after this time, we'll be able to apply it in the evening.
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First of the month, medication time. Had to double the dose of the heartgard, no longer a 25 lb pup... 💊


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