Pet Drug Reports

Afoxolaner: adverse event reports in all combinations

Active ingredient, alone and in combinations

Brand names with this ingredient: NexGard.

The openFDA records give the value "MSK" for the brand name and for the manufacturer name of each drug. FDA says that MSK means "masked". So the site cannot count a report for a brand.

Read this first. FDA says this about the data:

An API dataset query result cannot be used to estimate the risk associated with the product or compare one drug or device product with another. When looking at the results, be aware that there is no certainty that the reported drug or device caused the adverse event. This dataset should not be the sole source of information for clinical decision-making or other assumptions about the safety or effectiveness of a product. The adverse event may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources.

FDA Center for Veterinary Medicine publishes these words. Source: Adverse Event Reports for Animal Drugs and Devices, read on . The data have the reports that FDA received through .

This page is not veterinary advice. For an animal that is ill, speak to a veterinarian.

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FDA reports received through . Counts include this ingredient alone and in combinations. Why brand names have no separate count.

From April 2013 to June 2026, FDA received 71,148 adverse event reports that name a drug with afoxolaner, alone or in a combination. 3 sets of active ingredients with afoxolaner have a drug page.

Of the 71,148 reports, 65,969 (92.7%) are about dogs. In January to March 2026, FDA received 1,538 reports that name afoxolaner, alone or in a combination. The signs that appear in the largest number of the 71,148 reports are "Vomiting", "Lethargy" and "Diarrhoea". A report is not proof that a drug caused a sign.

Reports that name this ingredient fell by 2.8% in the 12 months to June 2026, compared with the 12 months before. Reports for all animal drugs fell by 4.6% in the same periods. The newest months can get more reports in a later update. Reports about dogs are 92.7% of the reports that name this ingredient, and 72.6% of all reports.

Reports in the latest closed quarter

Reports that name afoxolaner, by the quarter in which FDA received them
SpeciesJan to Mar 2026Oct to Dec 2025Jan to Mar 2025
All species1,5381,6751,383
Dog1,4391,5631,254
Cat551
Horse000
Other or not given94107128

January to March 2026 is the latest closed quarter in the data.

All updatesFeed of updates (RSS)

Drug pages with afoxolaner

A report names a drug by its set of active ingredients. Each set with afoxolaner that has a drug page is in the table, in order of name. The table has 3 sets.

Drug pages with afoxolaner, in order of name, with the reports of each page
Active ingredientsReports, all yearsReports, latest 12 months
Afoxolaner61,4282,823
Afoxolaner + Milbemycin Oxime366
Afoxolaner + Moxidectin + Pyrantel Pamoate10,0964,386

A report can name more than one set, so the counts of the sets can add to more than the count of the page.

An API dataset query result cannot be used to estimate the risk associated with the product or compare one drug or device product with another.

FDA Center for Veterinary Medicine. Source: Adverse Event Reports for Animal Drugs and Devices

Signs that the reports list

A sign is a coded term from the report. The words in brackets are a plain gloss of the term. The percentage is the share of the 71,148 reports that list the sign. One report can list more than one sign and more than one drug.

The sign that is in the largest number of the reports comes first.

  1. Vomiting22.9%16,258 reports
  2. Lethargy[unusually tired or inactive]10.3%7,353 reports
  3. Diarrhoea[diarrhea]8.8%6,262 reports
  4. Lack of efficacy (ectoparasite) - tick NOS[the product did not have the expected effect: ticks]7.3%5,200 reports
  5. Lack of efficacy (ectoparasite) - flea[the product did not have the expected effect: fleas]6.5%4,633 reports
  6. Seizure NOS[seizure, type not specified]6.3%4,515 reports
  7. Lack of efficacy (bacteria) - Borrelia[the product did not have the expected effect: Borrelia (Lyme disease bacteria)]5.4%3,844 reports
  8. Lack of efficacy (tick)[the product did not have the expected effect: ticks]4.8%3,389 reports
  9. Skin disorders NOS[NOS: not otherwise specified]3.7%2,626 reports
  10. Lack of efficacy (bacteria) - NOS[the product did not have the expected effect: target not specified]3.7%2,608 reports
  11. Pruritus[itching]3.5%2,458 reports
  12. Tablets, Abnormal[a product quality report, not a sign in an animal]3.4%2,434 reports
  13. Itching3.1%2,191 reports
  14. Lack of efficacy (endoparasite) - heartworm[the product did not have the expected effect: heartworm]2.7%1,926 reports
Show the next 16 signs
  1. Not eating2.6%1,854 reports
  2. Anorexia[not eating]2.6%1,836 reports
  3. Lack of efficacy (flea)[the product did not have the expected effect: fleas]2.3%1,632 reports
  4. Panting2.2%1,561 reports
  5. Behavioural disorder NOS[behaviour change, type not specified]2.1%1,474 reports
  6. Lack of efficacy (endoparasite) - hookworm[the product did not have the expected effect: hookworms]2%1,413 reports
  7. Shaking1.9%1,324 reports
  8. Lack of efficacy (bacteria) - Anaplasma[the product did not have the expected effect: Anaplasma bacteria]1.8%1,312 reports
  9. Scratching1.8%1,260 reports
  10. Other abnormal test result NOS[abnormal laboratory result, type not specified]1.7%1,216 reports
  11. Ataxia[unsteady, uncoordinated movement]1.7%1,207 reports
  12. Death1.6%1,143 reports
  13. Lack of efficacy (bacteria) - Ehrlichia[the product did not have the expected effect: Ehrlichia bacteria]1.2%840 reports
  14. Death by euthanasia[the animal was euthanized]1.2%834 reports
  15. Lack of efficacy (endoparasite) - roundworm NOS[the product did not have the expected effect: roundworms]1.2%831 reports
  16. Inappetence[reduced appetite]1.2%827 reports

Download all signs (CSV)

Reports by species

  • Dog92.7%65,969
  • Human exposure0.1%92
  • Cat0.1%86
  • Otherunder 0.1%3
  • Other Canidsunder 0.1%3
  • Foxunder 0.1%1

Reports for each month, Jul 2021 to Jun 2026

Dog26,168 reports. Largest count in one month: 732 (May 2024)
Cat44 reports

No chart: no month has 5 or more reports.

Horse0 reports

No chart: no month has 5 or more reports.

Other or not given2,037 reports. Largest count in one month: 73 (May 2024)

The month is the month in which FDA received the report. Each chart has its own scale. FDA says that a report can take 3 to 6 months to reach the public data. The newest months can get more reports in a later update.

Reports by year

  • Dog
  • Cat
  • Horse
  • Other or not given
Reports that name afoxolaner, by the year in which FDA received them and by species
YearDogCatHorseOther or not givenAll species
20263,146801773,331
20256,8141405127,340
20246,600605967,202
20234,0861303404,439
20223,609202483,859
20214,107103454,453
20204,791704195,217
20195,115704325,554
20184,823403885,215
20177,2091005937,812
20167,224805107,742
20155,544313525,900
20142,881301753,059
20132000525

2026 has the reports that FDA received through Jun 2026. Download the years (CSV)

What the reports record

Outcome at the time of the report

  • Recovered/Normal28%19,955
  • Recovered with Sequela[recovered, with a lasting effect]0.2%146
  • Ongoing9%6,385
  • Died1.7%1,224
  • Euthanized1.1%815
  • Outcome Unknown52.8%37,595

An outcome in a report is not proof that the drug caused it. The person who sends the report gives the outcome. Each share is of the 71,148 reports that name afoxolaner.

Kind of report

  • Safety issue58.8%41,862
  • Lack of expected effectiveness30.7%21,822
  • Both safety and lack of expected effectiveness3%2,124
  • Manufacturing or product defect7.4%5,256
  • Other0.1%84

Age of the animal

  • Under 1 year13.5%9,580
  • 1 to 3 years26%18,499
  • 4 to 7 years21.1%15,017
  • 8 to 11 years14.1%10,024
  • 12 years and over6.1%4,366
  • Age not given19.2%13,662

Each share of kind and age is of the 71,148 reports that name afoxolaner.

Approved animal drugs with this active ingredient (FDA Green Book)

This section is reference data. It has no report count.

The openFDA records give the value "MSK" for the brand name and for the manufacturer name of each drug. FDA says that MSK means "masked". So the site cannot count a report for a brand.

Brand names

  • NexGard

What the Green Book records give

Applications with an approval in force
2
Approved species
Dogs
Dose forms
Chewable Tablets
Routes
Oral
Sale
RX (prescription)
Earliest approval date in the records

The species, dose forms and routes are the words of the Green Book records for all the applications together. One product can have fewer. The label of a product gives its approved use.

Applications in the Green Book of 2 Nov 2026, pioneer applications (NADA) first
Brand nameActive ingredientsSponsorApproved speciesApplication
NexGardAfoxolanerBoehringer Ingelheim Animal Health USA, Inc.DogsNADA 141-406
NexGard PlusAfoxolaner, Moxidectin, Pyrantel PamoateBoehringer Ingelheim Animal Health USA, Inc.DogsNADA 141-554

FDA pages for this ingredient

The site checked these addresses on . The links open in a new tab.

Cite this page

Pet Drug Reports. Afoxolaner, all combinations: adverse event reports that FDA received. https://petdrugreports.com/ingredient/afoxolaner/ Source: FDA Center for Veterinary Medicine, openFDA Animal and Veterinary adverse event reports, export of . Reports received through .

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Where the data come from

The counts come from the openFDA Animal and Veterinary adverse event files, export of 30 Oct 2026. The files have the reports that the FDA Center for Veterinary Medicine received through 26 Jun 2026. The files mask brand and manufacturer names. The site counts a drug by the active ingredients that each record gives, and gives no count to a brand, an application or a company. Ingredient names and the lists of approved products follow the FDA Green Book of 2 Nov 2026. Ingredient names follow the Green Book, with salts and forms as FDA lists them.

The site does not publish report text, lot numbers or details of a reporter. FDA's record is the authority. See how the site counts reports, the data sources and the corrections page.

Questions about these reports

Which brand are these reports about?

The openFDA records give the value "MSK" for the brand name and for the manufacturer name of each drug. FDA says that MSK means "masked". So the site cannot count a report for a brand. The Green Book section of this page lists brand names with this active ingredient.

Do the reports show that the ingredient caused the signs?

No. A report can name more than one drug, and a drug can have more than one active ingredient. FDA states this about the data.

When looking at the results, be aware that there is no certainty that the reported drug or device caused the adverse event.

The adverse event may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources.

FDA Center for Veterinary Medicine. Source: Adverse Event Reports for Animal Drugs and Devices

How many reports did FDA receive in the latest 12 months?

FDA received 7,084 reports in the 12 months to June 2026. It received 7,291 reports in the 12 months before. FDA says that a report can take 3 to 6 months to reach the public data. The newest months can get more reports in a later update.

What kinds of report are in the count?

Of the 71,148 reports received from April 2013 to June 2026, 58.8% are about a safety issue only. 33.7% are about a lack of expected effectiveness, alone or with a safety issue. 7.4% are about a defect of the product or its package.