I’ve been a veterinarian since 1993 and have been in vet clinics most of my life. In that time I’ve seen lots of heartworm and flea products come onto the market. They each have pros and cons. We in South Florida need to keep our pets on heartworm preventatives! We live in paradise, but it is also the heartworm war zone. The following list is the products I carry for flea and tick and heartworm prevention. I discuss when I might choose which. Hopefully, this article will help you choose what option is best for your pet.
SENTINEL SPECTRUM (This is my hands-down favorite product for dogs due to its safety profile and affordable price.) Sentinel has been on the market for many years. It contains milbemycin, the same active ingredient as in Interceptor and Trifexis. Milbemycin is very safe for all breeds. I chose to carry Sentinel Spectrum because it is a tasty chew Sentinel Spectrum contains a Program (aka lufenuron) which is “birth control” for fleas. Lufenuron prevents the formation of chitin which is a flea’s exoskeleton. Mammals don’t have an exoskeleton. Mammals don’t have chitin! If your dog takes lufenuron (which is in Sentinel Spectrum), any flea eggs in the environment exposed to your pet cannot hatch. The flea’s “egg tooth” (the little triangular piece that the larva claws its way out of the egg to hatch) is made of chitin! This is both disgusting and cool at the same time. Yes, I said larvae. The vast majority of the flea population are eggs, followed by flea larvae, the pupae and then a very small percentage of the flea population is adult fleas. Nobody wants flea larvae in their carpets. Lufenuron is EXTREMELY SAFE flea control.
Sentinel Spectrum treats hookworms, whipworms and roundworms, and 2 types of tapeworms and is a heartworm preventative Sentinel Spectrum does NOT treat ticks. And as I mentioned above, it acts as birth control for fleas, but it does NOT kill adult fleas. Nonetheless, it will likely prevent a random hitch-hiker flea who jumps onto your pet outside from turning your house into a flea-infested home. For the typical city slicker dog in Jupiter and Tequesta, using Sentinel Spectrum year-round and adding in Nexgard or Bravecto in the summer months is a great option. If the pet is a rootin’ tootin’ outdoorsman, we will recommend a flea adulticide product year-round in addition to the Sentinel Spectrum.
I know my clients. Most of us do not want to put our pets on flea and heartworm and tick products. I get it. I’m from Oregon, home of tree-hugging hippies. I rarely take medication myself. I understand when my clients don’t want to use a flea adulticide product year-round. If my dog patients are on Sentinel Spectrum it is highly unlikely that they will get internal parasites, heartworm disease, or have a flea infestation.
The only thing Sentinel Spectrum doesn’t address is ticks. Finally, Sentinel Spectrum is a hydrolyzed protein. We treat a lot of allergy dogs here in South Florida. If a pet is on a special hypoallergenic diet we don’t have to worry about setting off an allergy flare each month when the pet receives a heartworm prevention dose.
IVERHART MAX AND HEARTGARD PLUS (These are 2 very similar products.
I have a preference for Iverhart Max over Heartgard Plus simply because Iverhart Max has a hydrolyzed protein and is a little more broad-spectrum and just a tiny bit less expensive than Heartgard Plus.) I am a huge fan of Iverhart Max and Heartgard Plus. These 2 products are essentially the same thing except Iverhart Max also has a tapeworm medication called Praziquantel. Both of these products contain ivermectin and Pyrantel. Both have been out for years and are very tasty and effective. They not cause nausea.
Word on the dog street is that they are truly delicious. It so much easier giving a pet medication when the pet gobbles it up as if it were a treat. Not all heartworm preventatives are so tasty. For herding breeds, we usually choose Sentinel Spectrum as ivermectin (the active ingredient in Heartgard Plus) can adversely affect herding breeds. This herding breed receptor defect is rare and at the dose in Iverhart Max or Heartgard Plus, it would be unlikely to cause issues. Nonetheless, we do still guide the herding breeds toward milbemycin (the active ingredient of Sentinel Spectrum).
Iverhart Max and Heartgard Plus treat roundworms and all 3 types of hookworms. They are also heartworm preventatives. Iverhart Max and Heartgard Plus are given monthly. They do nothing for fleas nor ticks. I usually pair Iverhart Max and Heartgard Plus with Nexgard or Bravecto.
TRIFEXIS (I no longer carry Trifexis even though it was once my favorite HW/flea product about a dozen years ago. We now have better options.) I like Trifexis. It is the combination of milbemycin (what is in Sentinel and Interceptor) plus Comfortis (which is a flea adulticide). I carried Trifexis in my pharmacy when I opened Tequesta Vet Clinic. It’s a great product—very effective for heartworm prevention and fleas and internal parasites, all in one pill.
Unfortunately, Trifexis has a few issues. The biggest complaint I heard is that it doesn’t taste good! Clients told me repeatedly how they have to cut it into bits and hide it in food or just send it down the hatch manually. It’s a hard little pill. Additionally, some pets will vomit when they take Trifexis, especially if they take it on an empty stomach. If a pet has a history of seizures, we do not recommend Trifexis.
The evidence is fuzzy, but we err on the side of caution. Any neurologic patient should steer clear of Trifexis due to the Comfortis component. Nonetheless, most pets do very well on Trifexis! If a client wishes to use Trifexis, we can set up a prescription through our online pharmacy. Trifexis does NOT treat for ticks.
REVOLUTION Revolution has been on the market for many years. It is a topical flea and heartworm preventative. It is a great product for treating fleas and for heartworm prevention. Unfortunately, it doesn’t do a very good job for internal parasites for dogs. (It is better for gi parasites in cats.) The company recommends that pets who take this also take pyrantel (one of the ingredients in Iverhart Max and Heartgard Plus).
Back when I was a relief vet I worked out at the clinic in the farms for a few months. The owner of that practice really loved Revolution. I saw numerous pets who were on Revolution present with hookworm infestations. We are (unfortunately) in hookworm country. For this reason, I’m not the biggest fan of Revolution. I also saw 2 dogs at that practice who came up positive for heartworm despite the owners’ claims that they had not missed a dose. Both of these dogs were very furry dogs and I suspect they were treating the fur rather than getting the liquid onto the skin. For this reason, I’m more trusting of oral heartworm preventatives than topical heartworm preventatives.
Nonetheless, Revolution has a couple of instances where it is FANTASTIC… One of my favorite times to use Revolution is for the very small breed of dogs. Many of these dogs don’t like to take oral options for heartworm prevention. Revolution can be used in dogs less than 5 pounds. If we have a pet with a food allergy, Revolution can be used as it is topical. Another time when I reach for Revolution is for very itchy dogs. We see TONS of allergy dogs here in South Florida. Sometimes we wonder if there is underlying SARCOPTIC MANGE (aka scabies). Scabies is really hard to identify. These mites are stinkers to find on skin scrapings and sometimes we will treat with Revolution, every 2 weeks instead of every month, for a total of 3 treatments. When we have a very itchy pet (particularly if they don’t respond well to our allergy treatments), we may try this 3 dose trial of Revolution.
Flea control: NEXGARD and BRAVECTO I love Nexgard and Bravecto. Nexgard was the first of the oral flea and tick preventatives that came on the market. I carried Nexgard when it first became available. Then later that year a sister drug came onto the market called Bravecto. Later 2 more sister drugs came out in the same drug class (Simparica and Credelio). Nexgard is still my favorite and in 2017 it got FDA labeling as a Lyme Disease preventative.
Nexgard and Bravecto both kill ticks and fleas. Nexgard lasts for one month for fleas and ticks. Bravecto lasts for nearly 4 months for fleas and 2 or 3 months for ticks. Bravecto is coming out with a one-month version as well and word on the street is that Merck may soon pair it with milbemycin. That will be a great combination for South Florida doggies! It’s easier to give a Nexgard along with your heartworm preventative than try to remember to give Bravecto every 3 or 4 months. If you have memory issues, buy the Nexgard. Nexgard is a smidge more expensive than Bravecto.
Both Nexgard and Bravecto are very effective against Demodex mites. Demodex (aka mange) is very common in the environment. Puppies are particularly prone to demodex until their immune system fully develops. Bravecto is approved for pets 6 months and older (per the company) simply because if it is given to a younger pet the pet may grow out of the weight range before the 3 month period is up.
Topical flea meds for dogs I do have a negative bias for topical medication simply because I don’t like petting a dog and having the topical goo on my hand. I typically rely on oral flea medications for dogs because of this. (Note below that I tend to use topical medications for cats because many people have trouble getting oral medications into their cats.) I no longer carry any of the following flea products at TVC but will discuss them below.
ACTIVYL Activyl is a great drug. It is a topical that is approved for puppies 8 weeks of age and older. Activyl is a flea adulticide that has flea repellent qualities that are fantastic. It also kills the immature stages of fleas. If a pet is exquisitely sensitive to flea saliva, I may add Activyl into the treatment protocol. Activyl came out about 5 or 6 years ago and there is no known flea resistance to it. It is a topical medication.
ADVANTAGE Advantage came out the year I graduated vet school in ’93. It has been a wonderful thing. There is minimal drug resistance and it remains a fantastic option for flea control. Again, I’m not a fan of topicals on dogs. It can be purchased over the counter at pet stores. There is a fancier option for Advantage called Advantage Multi that has moxidectin for added heartworm protection. We do not carry either of these products for dogs because I prefer oral heartworm and flea preventatives for dogs. And, if I do have a dog with a food allergy (as many of the orals have beef or pork), I tend to reach for Revolution as my topical medication of choice.
FRONTLINE Frontline came on the market in the early 90s and I loved it for years. It has a high safety profile, particularly for pets with neurological conditions. Unfortunately, there is significant drug resistance to Frontline. The sturdy fleas we have in SoutFlorida laugh at Frontline these days. If you have Frontline, please give it to your friends up north. The fleas in the northern USA are pansies compared to our badass South Florida flea population. One UF dermatologist calls the fleas we have down here in South Florida “terrorist fleas”. We don’t carry Frontline and don’t recommend it. There are numerous generics of Frontline available over the counter. Frontline better than nothing at all, but we don’t recommend Frontline nor the generics in South Florida.
SERRESTO COLLARS FOR DOGS I’ve never been a fan of flea collars, but the Serresto collar (for both dogs and cats) is the best I’ve seen. It lasts for 8 months and has flea and tick repellent qualities. It needs to be snug to the skin (can slide 2 fingers between the collar and the pet) and once applied should not be removed. In general, I prefer Bravecto or Nexgard over the Serresto Collar, but for folks who snowbird up north where there is a much worse tick issue, this is a good choice. I hear they sell like hotcakes up north. I usually have a few on the shelf (for our snowbird clients), but rarely sell them.
FLEA AND TICK AND HEARTWORM CONTROL FOR CATS:
We’ve come a long way with heartworm and flea prevention for kitties in the last year! For cats in Florida, we strongly prefer to have heartworm prevention included with the flea treatment. There is no treatment for heartworm disease in cats. Yes, you can get Advantage and Frontline over the counter, but they do not have tick nor heartworm prevention in them. Furthermore, Frontline has significant flea resistance. Please never use permethrin or pyrethrin on your cat. Back in the 1990s, I treated many cats who were poisoned (presenting with tremors and seizures) by the use of permethrins and pyrethrins. We currently carry Revolution Plus and Bravecto Plus for our feline patients. In the past, we carried regular Revolution and Advantage Multi and regular Bravecto.
BRAVECTO PLUS FELINE
Bravecto Plus for Cats is a new product. It is a topical and lasts for 2 months for cats. For cats who are difficult to catch (especially feral cats), this flea product is fantastic! Or, if other products have failed you in the past, there is no known flea resistance to this product. Bravecto Plus has Bravecto (fluralaner) and moxidectin for heartworm prevention and roundworm and hookworm treatment. It is fantastic. You just need to remember to give it every other month. This is Joi’s favorite product for cats. It can be used in cats 6 months of age and greater than 2.6 lbs.
Revolution has long been a great flea product. For cats, it is also great for roundworm, hookworm, and ear mites. Recently Zoetis added Sarolaner for even better flea control AND tick control. It is used once monthly for cats. It is a topical. Revolution Plus can be used in cats 8 weeks of age and older and cats 2.8 lbs or more.
SERRESTO COLLAR FELINE
I’ve never been a fan of flea collars, but the Serresto collar (for both dogs and cats) is the best I’ve seen. It lasts for 8 months and has flea and tick repellent qualities. It needs to be snug to the skin (can slide 2 fingers between the collar and the pet) and once applied should not be removed. It doesn’t have a “breakaway” piece should a cat get caught by the collar. I’ve seen cats come in with a Serresto collar and yet still have fleas. This is likely because most folks don’t wish to keep the collar on snugly. I prefer Bravecto Plus and Revolution Plus over the Serresto Collar.
I hope this helps you choose the best product for your pet. Please don’t hesitate to ask me or my staff if you need guidance!