Simparica vs. Comfortis : Comparison and Key Differences

You and your pet are going along just fine when it happens. Scratching. Then more scratching. Before you know it, your pet is miserable, and you aren’t sure how you got here. Even indoor pets can catch flea infestation, so it’s essential that you get ahead of a potential problem before it causes you and your pet massive discomfort.

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Chewable flea and tick treatments are all the rage. They’re easy to use and don’t cause a massive mess on your hands or your furniture. You don’t have to worry about them being waterproof. It’s a simple solution to a messy problem.

Simparica and Comfortis are both available through prescriptions, but which one should you choose? Your vet can give you plenty of advice for making the right decision for you and your pet, but in the meantime, we’ve broken down the differences to help give you an idea. Let’s get started.

Which is Better Simparica or Comfortis for Dogs?

Both options are suitable for dogs, but Simparica’s ingredients do a slightly better job of eliminating fleas and keeping them away for more extended periods of time. Studies show a better rate of flea control with Simparica. Although Comfortis does an excellent job of killing flea infestations, dogs retain better control for longer periods of time with Simparica.

It’s also less likely to be rejected by picky dogs than the Comfortis tablet. Researchers had more success offering the tablet than they did the Comfortis one, so if your dog is picky, this might be a better option.

Comfortis is available for younger dogs (14 weeks) than Simparica (six months), but once that age passes, we’d switch to Simparica.

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Which is Better Simparica or Comfortis for Cats?

In this case, the only option for cats is Comfortis. It’s vital that you use a formula meant specifically for cats because feline biology is different than canine. It’s ineffectual at best and dangerous at worst to give a cat a canine formula.

Comfortis has a line of chewables explicitly made for cats. This is the route to take between the two, but you could talk to your veterinarian about other safe options as well.

Our Review of Simparica and Comfortis

They have some things in common as far as how the drug works. Both use a neurotoxin to interrupt the breeding and feeding cycle of fleas and prevent new infestations by preventing fleas from laying eggs. They also both require a prescription and come in a pleasing chewable tablet meant to mimic a treat.

Key Differences Between Simparica and Comfortis

There are a few differences, however, between the two and not just in age. Let’s break it all down.


Simparica must wait until your dog is at least six months old before beginning treatments. That leaves you finding alternatives until your puppy is the right age. Comfortis can be given a little bit earlier at 14 weeks of age. Depending on how old your dog is when you start treatment, this may make a big difference.

For those with younger dogs, you may want to start with one sort of treatment and switch later to Simparica. It’s possible to use even a temporary spot on treatment in the meantime.

Other Parasites

Comfortis is meant for controlling flea populations, but for those of you with outdoor friendly dogs, you may also be worried about ticks. Simparica is just as effective at dealing with ticks as fleas, giving it a wider range of protection.


Both are close in price, but Simparica is a shade cheaper. Also, the effective range is actually 35 days instead of a month. Taken together, that difference can add up over a longer period of time. And it’s not just that. Simparica also covers a broader range of pests.


Both tablets are flavored, but Comfortis is a beef flavored chewable and Simparica is a liver flavored chewable. If your pet is picky, this could give you more options for administration. Studies favored the liver flavored tablet of Simparica as well, so if your dog is picky, you may want to try what studies showed to be a favorite.

Simparica and Comfortis Active Ingredients Comparison

Although both rely on neurotoxins to control fleas, the specific toxin is different. Both have few side effects and are relatively effective in controlling flea populations quickly and efficiently.

Simparica: Sarolaner

Sarolaner is a class of neurotoxin that interrupts the nervous system of a biting insect. The insect experiences spasms and is unable to eat or complete the breeding cycle. It’s relatively side-effect free although rate instances have dogs suffering digestive issues.

Comfortis: Spinosad

Spinosad is a neurotoxin found naturally in the soil and isolated into a tablet form. It controls flea populations by causing nervous systems to misfire, so the insect is no longer able to feed. It prevents fleas from laying eggs and can eliminate an infestation within three months. It also has relatively few side effects, but ones that happen usually are digestive issues of some kind.

Which Treatment is the Best Priced?

Like we mentioned above, Simparica is more economical overall. They both require a prescription to use, so that’s a wash, but Simparica is cheaper for six treatments than Comfortis is. It also gives you a few extra days of effectiveness and helps to control tick populations as well. It provides better coverage for less, so overall, it’s the value option.

Which Do We Recommend?

We appreciate Comfortis’s effectiveness for younger puppies and for cats, but overall, we love Simparica. Dogs are more likely to take the chewable in the first place if it’s the liver flavored one. We like knowing that ticks are also a thing of the past.

Since we don’t mind waiting for the right age, we think you’ll be happier overall with the effectiveness of Simparica for your dogs. Studies favor the efficacy of Simparica’s neurotoxin, so we recommend that you start there with the blessing of your veterinarian.

Your cats will need an alternative treatment or to go with the Comfortis feline option.

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7 Treatment Application Tips

Even if your pet is primarily indoors, you still need to use a flea preventative. Outdoor pests can work their way into your home in many different ways, and it just takes one or two fleas to have an infestation. You can’t rely on removing individual fleas either because flea eggs can quickly turn the problem into a huge situation.

Chewables may be natural alternatives to topical treatments, but that doesn’t mean your dog (or cat) won’t cause some issues. Here are a few things you can do to help everything go a little more smoothly.

1. Dogs that don’t like the chewable treatment can be enticed to take a tablet in a few different ways. One really common method is to bypass your dog’s sense of smell by disguising the tablet in something else. Dog’s use their sense of smell to determine if something is tasty or not, so you could wrap the treat in a piece of cheese or in something like tuna oil to help encourage your dog to eat it.

2. You could also try the sandwich method. Take two treats that your dog loves and make sure your dog can smell them. Give the first treat and capitalize on your dog’s excitement by quickly giving the chewable treatment. Follow up immediately with the second favorite treat. This can help your dog get through the prevention chewable without too much fuss.

3. Cats can be trickier. Something that often works on cats (and really stubborn dogs) is having a chewable “accidentally” fall from the counter where you are preparing food. Cats and dogs may feel like they’re getting something unexpected and exciting and eat the chewable before realizing that it’s just a flea prevention medication and not a tasty piece of food.

4. You can use your dog’s natural sense of play and curiosity, too. You could throw treats into the air for your dog to catch, and throw the chewable in the middle of that game. You could hide fun treats and make sure the chewable is among them to find. You could have your pet choose which hand has the treat and make one of the rounds a chewable. There are so many ways to help your picky pet take a chewable without having to switch back to a spot-on treatment.

5. A few days before giving a chewable tablet, make sure that you don’t introduce any new or unexpected treats or food. If your dog has a reaction to the tablet, it can be difficult to know if the tablet or the new food is to blame. Eliminating all but basic food and water a few days before and after can make it really clear when your pet is having trouble with the tablet.

6. Another reason to avoid new food or treats is that if your pet has a reaction to one of those, it may associate those feelings with the chewable itself even if that didn’t cause an issue. The next time you deliver a chewable, it might be even more challenging to get your pet to take the chewable willingly. Anything you can do to eliminate stomach issues each time you give the chewable can help everything go smoothly.

7. Watch your pets for a few days to see if any behavioral changes hint at a problem. Pets are notoriously stoic about pain and discomfort, so it’s up to you to see any small changes that could indicate a problem. If you think something is off, it’s best to go ahead and have your veterinarian check your pet out to alleviate any possible issues.

Final Thoughts

The chewable market is getting bigger, but we are fans of Simparica’s effectiveness and its price. Once you talk to your vet about your options, we think you’ll be pleased with the way Simparica works.

For cats, get suggestions from your vet for safe alternatives to Simparica including Comfortis. Your vet can steer you to the right prevention method whether chewable or spot on. Spot on treatments are more common for cats, but companies like Comfortis are noticing that even cat owners need the ease of a chewable tablet. You should be able to find a safe alternative.

Make sure your pet is covered so that even accidental pests are eliminated quickly. Your pet’s quality of life increases, and you don’t have to deal with the constant itching. That’s a win-win in our book.

What treatments are you thinking about for your cat? Are you going with a chewable treatment or a spot on? Tell us your thoughts in the comments below.

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