Is your pooch feeling miserable from constantly scratching and biting at those pesky fleas?

Your pet’s problem could be solved with the simple administration of a yummy tasting tablet.

Read on for a comprehensive breakdown of Simparica for dogs.

Pet flea control in tablet form

dog taking simparica

With the abundance of parasiticides available today which protect our dogs from ectoparasites, it’s vital for us to examine how safe and effective these products are.

As of September 21, 2018, the FDA began alerting pet owners and veterinarians of the potential neurologic adverse events in dogs and cats when treated with drugs that are in the isoxazoline class. The FDA-approved drugs in this class include Simparica.

To keep those pesky pests at bay, check out these flea collars for dogs.

“These products are approved for the treatment and prevention of flea infestations, and the treatment and control of tick infestations. Although these products can and have been safely used in the majority of dogs and cats, pet owners should consult with their veterinarian to review their patients’ medical histories and determine whether a product in the isoxazoline class is appropriate for their pet.” [1]

What is Simparica?

simparica for dogs

Simparica (Sarolaner (Simparica™ chewable tablets, Zoetis), is widely used by veterinarians for the treatment and prevention of flea and tick infestations in dogs. It is one of the latest additions to the isoxazoline class of oral ectoparasiticides and is an extremely potent insecticide and acaricide. [2]

How it works in the body

It received FDA approval in 2016. Sarolaner works by inhibiting the function of the neurotransmitter gamma-aminobutyric acid (GBA) receptor, and glutamate receptor. It works at the neuromuscular site in insects, leading to the elimination of insects or acarines.

More importantly, it controls ticks such as the Lone Star tick, Gulf Coast tick, American Dog tick, black-legged tick, and the brown dog tick.

Simparica presents in the form of a flavored chewable tablet that is effective from day one to day 35, and can be given to dogs six months and older. Flea and tick products like Simparica travel in the dog’s blood to safely and continuously deliver protection against fleas and ticks for 35 days.

Simparica works rapidly due to its active ingredient, sarolaner, which is a systemic insecticide that is fast-acting and kills fleas within three hours after the administration of a flavored Simparica chewable.

What the studies show . . .

Sarolaner has insecticidal and acaricidal properties that work for the duration of a month. A study in Science Direct adds that:

“The sarolaner molecule has unique structural features important for its potency and pharmacokinetic (PK) properties, including spiroazetidine and sulfone moieties. The flea and tick activity resides in the chirally pure S-enantiomer, which was purified to alleviate potential off-target effects from the inactive enantiomer.”

Additionally, the study explains that:

Lone star tick

“In a head-to-head comparative in vitro assay with both afoxolaner and fluralaner, sarolaner demonstrated superior flea and tick potency. “ [3]

The study goes on to explain that these compounds have shown to be remarkable in their fast acting ability against common parasites in dogs – like ticks and fleas. Previously the best acaricides were for topical use only. Sarolaner has fast and consistent efficacy for the full dosing period against fleas and multiple species of ticks.

This is an essential attribute of effective ectoparasiticides in that Sarolaner improves primary parasite control, and reduces the potential for pathogen transmission. Products like Simparica will help with a more rapid onset of action, and will achieve both these aims.

Benefits of Simparica

The following are filed under Simparica benefits: [4]

  • it is effective against ticks within 8 hours after oral administration.
  • it starts killing fleas within 3 hours.
  • it has 35 days of full continuous protection against fleas and ticks.
  • it kills 5 tick species.
  • it helps to prevent ear mites, flea allergy dermatitis, tick bite fever, and anemia resulting from tick bite fever.
  • it is beneficial in treating sarcoptic mange.

Now that we know a little bit more about Simparica and what it does, let’s find out what it’s used for when it comes to our beloved dogs.

What it’s used for in dogs?

What is Simparica used for
Ahead we take a look at how Simparica is used in treating, preventing, and/or controlling certain conditions in dogs.

Flea allergy dermatitis

Simparica is used to control flea and tick infestations in dogs. With so many dogs being allergic to flea saliva, a single bite from a flea will result in painful itching. This sensitivity is called flea allergy dermatitis. Flea allergy dermatitis tends to occur mostly in the late summer.

Dogs younger than one year of age usually do not have flea allergy dermatitis. Diagnosis is made by visual observation by a dog owner and veterinarian by slowly parting the dog’s hair. This will often reveal flea excrement and fast-moving fleas.

Flea excrement is red and black in color, cylindrical, pellet or comma-shaped. Canine wipes or damp paper towels can be used to remove the excrement. Eggs, larvae, and flea excrement will most likely also be found on the dog’s bedding. With the presence of fleas, there is usually another problem that is closely linked to the dog’s painful itching and painful skin condition.

In this case, your veterinarian will do skin testing to eliminate any other causes of itching, and make a diagnosis of flea allergy dermatitis. Your veterinarian will most likely prescribe flea control measures, a treatment to control itchiness and a possible secondary skin disease in hypersensitive dogs. Fleas can also spread tapeworm, so keeping your dog free of parasites is an integral part of good health care.

When you’re in the midst of a medical crisis, these best first aid kits for dogs are sure to come to your rescue.

Prevention, control, and treatment of ticks

tick and flea prevention

Ticks are just as dangerous, and certain types of ticks transmit Lyme disease, Rocky Mountain spotted fever, Q-Fever, and Lyme Disease. If your dog has numerous ticks feeding off him, severe anemia and tick paralysis can result.

Ticks can survive from a few months to several years without food if they find themselves in the right environmental conditions. They are blood-sucking parasites that attach themselves to humans and animals. Ticks can also release toxins that can result in anemia, tick paralysis, and even death.

Some types of ticks may favor attaching and feeding around the head, neck and shoulder area, while other species of ticks will prefer the ear, anus, and beneath the tail area. For this reason, it’s essential to bring your dog to the veterinarian for a full check-up. The most obvious sign of a tick infestation is the presence of a tick on your dog. That said, it’s critical to determine which type of tick infestation is present.

Apart from keeping your dog away from tick-infested areas, plagued dogs need to be treated with the correct anti-tick or tick-control product. Simparica is used on a month-to-month basis for flea and tick control. If your dog overrun with ticks, your veterinarian will need to remove them.

Heavy tick infestation not only causes severe damage to the skin, but anemia, paralysis, and other complications can also result. A clinic stay for your dog will most likely be recommended by your veterinarian.

Treatment of scabies (sarcoptic mange) in dogs

Sarcoptes scabieiisThe clinical signs of sarcoptic mange include hair loss in dogs, as well as papules, pruritus, erythema, scaling and crusting. Sarcoptes scabieiis one of the most common mites infesting dogs today. It results in severe pruritus, and can lead to secondary bacterial pyoderma. Scabies is highly contagious, and is zoonotic, as well.

Published study:

A 2016 published study tested the efficacy of the novel isoxazoline, Sarolaner (Simparica) in dogs with clinical signs that were consistent with sarcoptic mange and harboring natural infestations of Sarcoptes Scabei. The study concluded that:

“Sarolaner was safe, achieved 100% reduction in the numbers of S. scabiei detected and resulted in marked improvement of the clinical signs of sarcoptic mange in dogs following two monthly oral administrations.” [5]

The study stated that with a monthly dosing schedule, –

“sarolaner could provide a very convenient and effective treatment option for dogs suffering from mite infestations.”

The study also evaluated whether two monthly doses of Sarolaner for the treatment of sarcoptic mange in dogs would work, and as to how safe two monthly doses were. The study surmised the following:

“Seventy-seven percent (77%) of sarolaner-treated dogs were free of mites on Day 14, 100% were mite-fee on days 30 and 60, and only one live mite was found on a single sarolaner-treated dog on Day 44 (Table 2). The percentages of dogs with live mites in the placebo group on days 14, 30, 44 and 60 were 52.4, 35.0%, 36.8 and 38.9%, respectively.

Only two of 11 (18%) placebo-treated dogs that did not receive any immuno-suppression harbored live mites on day 60. In contrast, one of three dogs (33%) that were started on immuno-suppression before day 30, and all four dogs (100%) that were immuno-suppressed for the entire study had live mites on day 60.”

Additional studies . . .

In another study regarding the safety and health observations of Sarolaner, the following was noted:

“There were no adverse health effects related to treatment with sarolaner noted in the study. In the placebo group, three dogs died during the study, two from canine ehrlichiosis and one due to glomerulonephritis. One additional, placebo dog was withdrawn due to a transmissible venereal tumor. Two dogs were removed from the sarolaner group when they were identified as being pregnant during the study.”

Sarolaner achieved 100% parasitological cure in both studies following two monthly administrations, and clinical signs of sarcoptic mange improved in treated dogs. The efficacy of sarolaner was non-inferior to the topically applied positive control in the field study. [6]

However, a parasitological cure was not achieved in one imidacloprid/moxidectin-treated dog after two monthly treatments whereas mites were eliminated from all sarolaner-treated dogs. Sarolaner tablets were also highly palatable with 90.5% acceptance by free choice within one minute of offering.”

The study deduced that:

“Sarolaner administered orally twice at monthly intervals at the minimum label dosage of 2 mg/kg was safe and achieved complete parasitological cure in dogs with natural infestations of Sarcoptes Scabiei. In addition, the clinical signs of sarcoptic mange improved without topical or systemic concomitant treatment, and Simparica™ chewable tablets were highly palatable.”

How much Simparica to give a dog?

Simparica dosage chart

Simparica is administered once a month as a flavored chewable.

Dosage is at 0.91mg/lb (2mg/kg) Simparica should only be administered to dogs 6 months of age and older.

  • 1 x 5mg tablet for 2.8 to 5.5 pounds
  • 1x 10mg tablet for 5.6 to 11 pounds
  • 1x 20mg tablet for 11.1 to 22 pounds
  • 1 x 40mg tablet for 22.1 to 44 pounds
  • 1x 80mg tablet for 44.1 to 88 pounds
  • 1 x 120mg tablet for 88.1 to 132 pounds

According to EMEA, Simparica was found to be well tolerated by animals treated with the recommended treatment dose of 2–4 mg sarolaner/kg bw. However, in the event of an overdose (3X or more the recommended dose), neurological effects (tremor, ataxia, convulsions) were observed.

Sarolaner is well tolerated in Collies with a deficient multidrug-resistance-protein 1 (MDR1 -/-) following single oral administration at 5 times the recommended dose. No treatment-related clinical signs were observed. Such dogs are particularly susceptible to treatment with macrocyclic lactones (e.g., ivermectin, milbemycin oxime, moxidectin, selamectin, etc.).”

Side effects of Simparica

Side effects of Simparica

Let us now look at possible side effects when administering Simparica.[7] Things like:

  • tremors
  • decreased conscious proprioception
  • ataxia
  • reduced or absent menace, and or seizures
  • Simparica is not recommended in lactating, pregnant females, or dogs used for breeding.

It is acceptable to use Simparica in conjunction with commonly prescribed vaccines, parasiticides, and other medications. When using Simparica, it’s vital to treat all animals within the household to maximize flea and tick infestation control.

Adverse reactions may include:

  • Diarrhea
  • Vomiting
  • Tremors
  • Ataxia
  • Bloody Diarrhea
  • Inappetance

“In a margin of safety study, Simparica was administered orally to 8-week old Beagle puppies at doses of 0, 1, 3, and 5 times the maximum exposure dose of 4 mg/kg at 28-day intervals for 10 doses. No adverse effects were observed at the maximum exposure dose of 4 mg/kg.

In the overdose groups, transient and self-limiting neurological signs were observed in some animals: mild tremors at 3 times the maximum exposure dose and convulsions at 5 times the maximum exposure dose. All dogs recovered without treatment.”

Sarolaner becomes highly bound to plasma proteins, and may compete with other highly bound substances like non-steroidal anti-inflammatory drugs (NSAIDs), and the cumarin derivative of Warfarin

Missed doses of simparica

Consult with your veterinarian as to the correct dosing schedule. Never double up on doses.

Simparica overdose

  • There is no antidote for sarolaner poisoning.
  • Treatment consists of preventing further exposure together with supportive and symptomatic measures.
  • After accidental ingestion, stomach lavage, as well as the administration of active charcoal administration, and laxatives may be advisable by your veterinarian.

Final thoughts on giving dogs Simparica

Healthy Golden Retriever

As of late, there are not many publications as to the toxicity of Sarolaner on the environment, or on pets. So far there have been 7 deaths related to Sarolaner.

That said, dog parents need to keep in mind that this drug remains in your dog’s bloodstream for an extended period and there are plenty of other options when it comes to flea and tick control, like natural flea and tick products with essential oils.

Feeding your dog a raw, whole food diet can also be beneficial. As usual, before opting for any flea and tick medications, consult with your veterinarian for the safest and healthiest options for flea and tick control!

Looking for other dog meds?


  1. Simparica (sarolaner) Chewables –
  2. Packianathan, Raj et al. “Efficacy and Safety of Sarolaner (Simparica®) in the Treatment and Control of Naturally Occurring Flea Infestations in Dogs Presented as Veterinary Patients in Australia.” Parasites & Vectors 10 (2017): 387. PMC. Web. 9 Oct. 2018.
  3. A novel, orally administered, broad-spectrum, isoxazoline ectoparasiticide for dogs.” Tom L. McTier. Nathan Chubb. Michael P. Curtis. Laura Hedges. Gregory A. Inskeep. Christopher S. Knauer. Sanjay Menon. Brian Mills. Aleah Pullins. Erich Zinse.r Debra J. Woods. Patrick Meeus. February 2016.
  4. Six, Robert H. et al. “Comparative Speed of Kill of Sarolaner (SimparicaTMChewables) and Fluralaner (Bravecto®) against Induced Infestations of Amblyomma Americanum on Dogs.” Parasites & Vectors 9 (2016): 399. PMC. Web. 9 Oct. 2018.
  5. “Efficacy and safety of a novel oral isoxazoline, sarolaner(Simparica™), for the treatment of sarcoptic mange in dogs.” C. Becskei. F. De Bock. J. Illambas. J. A. Cherni. J. J. Fourie. M. Lane. S. P. Mahabir. R. H. Six. 2016 May 30
  6. “Efficacy and safety of sarolaner against generalized demodicosis in dogs in European countries: a non-inferiority study.”. Becskei. Cuppens. Mahabir. 2018 June 29
  7. Stanneck, Dorothee et al. Evaluation of the Long-Term Efficacy and Safety of an Imidacloprid 10%/flumethrin 4.5% Polymer Matrix Collar (Seresto®) in Dogs and Cats Naturally Infested with Fleas And/or Ticks in Multicentre Clinical Field Studies in Europe.”Parasites & Vectors 5 (2012): 66. PMC. Web. 10 Oct. 2018.

About the Author


Claudia Bensimoun is a hard working, animal loving, dog journalist from sunny West Palm Beach, and specializes in veterinary content. A long-time contributing features writer for Animal Wellness magazine, Fido Friendly magazine, and the United States Dog Agility Association. She's also the author and ghostwriter of more than 50 dog eBooks. She's passionate about canine nutrition, canine health and wellness, and animal rescue/adoption. Her interests include wildlife conservation, animal welfare, disaster/ humanitarian relief, and veterinary research.

Read More Posts By: Claudia


  1. Lynn on December 29, 2018 at 11:45 am

    Symparica has caused multiple seizures on our 2 year old Cavalier King Charles after the 3rd monthly dose. Our vet thought it was epilepsy and recommended Phenobarbitol. We decided to stop Symparica and she had been seizure free ever since (almost 4 months now). This drug should not be sold in my opinion.

    • Jan Erickson on May 12, 2019 at 12:15 pm

      I gave my dog – English Cocker 11 yrs old – a first dose of Simparica on Friday and Saturday I really thought he was dying. He couldn’t hold his head up and his lips were white instead of the pink they usually were. The inside of his ears – usually bright pink – were also white. He just wouldn’t even move. Not even to go outside. It lasted from about 10 a.m. until 6 p.m. He slowly came back to us and drank some water and went outside to releave himself. Is this a usual side effect? It really scared me!

      Jan Erickson

  2. Paul Bradshaw on September 20, 2019 at 9:52 pm

    Administered this medication to my 10 year old small mix breed (5.5lbs) at the vetrenarian recommended dosage on a full stomach and the immediate result was bloody diarrhea. I tried this instead of the Comfortis and its attendant negative effects on the liver and kidney functoin that I was administering. I will not give this pesticide (poison) to my pet again and would strongly suggest the responsible pet owner investigate more homeopathic remedies for flea and tick control as opposed to the “magical” one pill cure all.

  3. Cecelia Buckner on October 16, 2019 at 5:57 pm

    On Sunday 10/13/2019 I gave a dise of simparica to my apple head Chihuahua the vet said he was slightly uderweight a prescribed Simparica. I came home from work today 3 days later to find him lifelees and trying to throw up. I will never give my pet this medication again need to be banned. Seeking treatment now.

    • K on December 29, 2019 at 8:07 am

      Yes it should be banned. My Schnauzer is now experiencing seizures because of it.

  4. Carol kwiat on December 23, 2019 at 1:54 pm

    I just saw this on tv. I would almost bet this “poison” is manufactured in China. They seem to want to kill off our beloved pets. Don’t use this stuff on your pets!!

  5. Nickolas Peros on May 17, 2020 at 7:45 am

    What are we doing to our pets? Feeding internal pesticide to kill, what, fleas? Folks, would you ingest poison to get rid of skin irritation? Why does anyone sell this poison in the first place. Brevecto too. I encourage people to sign this petition.

    Get a good flea comb and use it daily. Vacuum your house daily during flea season, and use natural products only to kill fleas. It is work, but worth it if we love our pets.

  6. REBECCA BARNES on October 7, 2020 at 12:10 pm

    My vet refused to prescribe any of these drugs and finally relented after research to prescribe Comfortis. He said giving Comfortis combined with Heartguard at the same time was the problem. And said to space out the two drugs 2 weeks apart. I have been doing this for 3 plus years now and no problems. My vet has sinced passed away and I am having a terrible time finding a new one. I tried a new vet with one of my dogs and after 2 visits for neck pain, teeth cleening and yearly exam come to find out he won’t prescribe Comfortis because of seizures, but has no problem with Simparica which can cause seizures as well. I’m so fed up. I think the Vet drug reps are as bad as the human drug reps and it’s a racket. Hawking their latest crap. I’m on the gulf coast and have to use a heartworm preventative and a flea med but don’t need a tick med. Years ago I gave my Brittany Spaniel her dose of Advantage or some topical and she rolled on her back and it took the polyurethane off the hard wood floors. This crap is all poison.

  7. Ann Bates on June 4, 2021 at 2:44 am

    I live out in the mountains near the Mediterranean in Spain. There are wild foxes boar rabbits of course and rodents in the scrub oak and pine forests hear, there is a lot of ticks and fleas but more seriously Mange and Leish in the wildanimals. My dogs run free on my property but so does the wildlife. Up to now I have been lucky using Seresto collar for keeping leish, ticks and fleas off my dogs but last month a few of them started coming down with mange. Seresto wasn t working. The mange mites even started biting me. I have had dogs in country settings for forty years and this is the first time i’ve had dermo problems with my dogs. These mites are everywhere and aggressive this year. I think they are living on the rodents too and spreading that way. Even I started getting bitten by those mites.! the situation required a serious immediate solution. My vet took scrapings off one of my worst affected dogs and prescribed simparica. 80mg ; my dogs weigh 25, 27, 28 and 29 kg. I gave them the pills yesterday, including to one who had just finished lactating. During the night one of her 4 kg puppies must have snuck a sip from her tit . I heard puppy howling and went out to find the pup in full seizures: growling howling at imaginary ghosts and pedalling. The breed is shepherd mix: labrador/beauceron cross. It is 12 hours later and the pup has calmed down but is still in seizure mode. I have seen pesticide poisoning before in humans in California. I hope this will wear off on my puppy but my suspicion is it won t and the damage is permanent. So far no adverse reactions in the big dogs except the one that weighed 25 kg is a bit lethargic. They have stopped with the mange mite scratching: that part I can definitely recommend. I would also caution to use it VERY precisely dosed..I think 80 mg for my 25 kg dog even though that is the mfg rec dosage might be making her lethargic…finally absolutely do not give to lactating bitches, if even a little sip produces this reaction in puppies!!! I would use it again ONLY as last resort for stubborn mange mites on well fed healthy adult dogs with strong natural immune system, and I would only use it till the mites were gone..maybe 2 months..I would never consider giving it to my dogs on a monthly basis.