Pet Drug Reports

Drugs by active ingredient › Ivermectin + Pyrantel Pamoate

Drug · combination of 2 active ingredients

Ivermectin + Pyrantel Pamoate: adverse event reports

All products with this ingredient combination · 3 FDA-approved applications in the Green Book

161,643reports naming this combination, 1993–202611.9% of all reports · about 4,962 a year
4,876reports, 12 months to March 20265,656 in the 12 months before
48.1%classed serious, as reportedof 111,861 reports stating it
1.8%record death or euthanasia, as reported2,906 reports
90.8%of reports concern dogs14.9% of all dog reports

FDA has received 161,643 adverse event reports in which a drug is recorded with the combination ivermectin and pyrantel pamoate as its active ingredients, from September 1993 to March 2026. The Green Book lists 3 FDA-approved applications with exactly this combination.

openFDA masks the brand and manufacturer in every report, so these figures describe the ingredient combination across all products and cannot be attributed to a brand.

In the 12 months to March 2026, 4,876 reports named it, down 14% from 5,656 in the 12 months before. Recent months are provisional: fDA posts reports quarterly with a delay of three to six months, so the newest months are incomplete and usually grow in later releases. Over its whole reporting history that is about 4,962 reports a year and 11.9% of all 1,357,245 reports (14.9% of all dog reports). How many animals received it is not published, so a count says nothing about how often a problem occurs per dose.

The most frequently coded terms are ineffective, heartworm larvae (21.4%), lack of efficacy (endoparasite) - hookworm (15.5%) and lack of efficacy (endoparasite) - heartworm (13.8%). A report can list several signs, so shares add to more than 100%; 2,003 different terms appear across these reports. Ineffective, heartworm larvae appears in 21.4% of these reports, about the same share as in the pooled reports for every drug containing ivermectin (19.1%).

90.8% of reports concern dogs. Not every report describes illness: 49.2% were filed wholly or partly as lack of expected effectiveness and 9.5% as product or packaging defects. Of reports that state seriousness, 48.1% were classed as serious, and 1.8% of all reports record a death or euthanasia as an outcome, as reported. FDA has not necessarily determined whether any drug played a part.

Monthly reports by species, five years

Dog29,658 · peak 801
Apr 2021: 732May 2021: 747Jun 2021: 708Jul 2021: 801Aug 2021: 669Sep 2021: 687Oct 2021: 662Nov 2021: 540Dec 2021: 500Jan 2022: 485Feb 2022: 533Mar 2022: 687Apr 2022: 589May 2022: 672Jun 2022: 460Jul 2022: 581Aug 2022: 639Sep 2022: 553Oct 2022: 592Nov 2022: 554Dec 2022: 415Jan 2023: 547Feb 2023: 454Mar 2023: 477Apr 2023: 552May 2023: 594Jun 2023: 603Jul 2023: 482Aug 2023: 638Sep 2023: 455Oct 2023: 573Nov 2023: 490Dec 2023: 332Jan 2024: 405Feb 2024: 409Mar 2024: 449Apr 2024: 525May 2024: 519Jun 2024: 502Jul 2024: 452Aug 2024: 519Sep 2024: 567Oct 2024: 423Nov 2024: 325Dec 2024: 267Jan 2025: 362Feb 2025: 315Mar 2025: 249Apr 2025: 420May 2025: 460Jun 2025: 459Jul 2025: 412Aug 2025: 410Sep 2025: 383Oct 2025: 399Nov 2025: 322Dec 2025: 292Jan 2026: 296Feb 2026: 298Mar 2026: 2162022202320242025
Cat7 · peak 1
May 2022: 1Feb 2023: 1Jan 2024: 1Mar 2024: 1Sep 2024: 1Oct 2024: 1Jul 2025: 12022202320242025
Horse0 · peak 1
2022202320242025
Other2,983 · peak 73
Apr 2021: 59May 2021: 68Jun 2021: 58Jul 2021: 53Aug 2021: 50Sep 2021: 51Oct 2021: 51Nov 2021: 46Dec 2021: 52Jan 2022: 45Feb 2022: 41Mar 2022: 65Apr 2022: 73May 2022: 51Jun 2022: 67Jul 2022: 65Aug 2022: 67Sep 2022: 66Oct 2022: 46Nov 2022: 57Dec 2022: 35Jan 2023: 46Feb 2023: 47Mar 2023: 69Apr 2023: 44May 2023: 59Jun 2023: 56Jul 2023: 49Aug 2023: 33Sep 2023: 39Oct 2023: 36Nov 2023: 23Dec 2023: 30Jan 2024: 47Feb 2024: 55Mar 2024: 47Apr 2024: 67May 2024: 53Jun 2024: 63Jul 2024: 41Aug 2024: 47Sep 2024: 56Oct 2024: 60Nov 2024: 57Dec 2024: 37Jan 2025: 59Feb 2025: 42Mar 2025: 47Apr 2025: 65May 2025: 62Jun 2025: 57Jul 2025: 51Aug 2025: 40Sep 2025: 43Oct 2025: 43Nov 2025: 36Dec 2025: 25Jan 2026: 56Feb 2026: 28Mar 2026: 22022202320242025

Reports by the month FDA received them. Each panel has its own scale; the peak month is printed at the top right. The newest months are incomplete because FDA posts reports with a delay of three to six months.

Reports by year received

05,56511,1291993: 219931994: 131995: 241996: 3719961997: 321998: 571999: 6019992000: 492001: 722002: 33220022003: 5862004: 1,7672005: 2,51320052006: 3,6022007: 5,0292008: 5,92220082009: 6,9682010: 6,6562011: 6,10720112012: 7,4972013: 8,6682014: 8,47320142015: 9,8482016: 10,5542017: 11,12920172018: 10,5942019: 10,8532020: 9,38620202021: 8,6992022: 7,4392023: 6,72920232024: 5,9962025: 5,0542026: 8962026

2026 covers reports received through March 2026 only.

Signs listed in reports

share of ivermectin + pyrantel pamoate reports listing the termall drugs containing ivermectinall dog reports

  1. Ineffective, heartworm larvae[legacy FDA term: the product did not have the expected effect (heartworm larvae)]21.4%34,603
  2. Lack of efficacy (endoparasite) - hookworm[the product did not have the expected effect: hookworms]15.5%25,126
  3. Lack of efficacy (endoparasite) - heartworm[the product did not have the expected effect: heartworm]13.8%22,378
  4. Vomiting10.8%17,538
  5. Digestive tract disorder NOS[digestive problem, type not specified]10.2%16,535
  6. Ineffective, ascarids NOS[legacy FDA term: the product did not have the expected effect (ascarids nos)]7%11,261
  7. Cardiac disorder NOS[heart problem, type not specified]6.2%10,040
  8. Diarrhoea[diarrhea]5%8,133
  9. Tablets, Abnormal[a product quality report, not a sign in an animal]4.7%7,613
  10. Lack of efficacy - NOS[the product did not have the expected effect]4.6%7,417
  11. Ineffective, hooks[legacy FDA term: the product did not have the expected effect (hooks)]4.2%6,845
  12. Lethargy[unusually tired or inactive]3.5%5,699
  13. Lack of efficacy (endoparasite) - roundworm NOS[the product did not have the expected effect: roundworms]3.1%5,006
  14. Containers, Damaged[a product quality report, not a sign in an animal]2%3,195
  15. Seizure NOS[seizure, type not specified]1.5%2,471
  16. Lack of efficacy (protozoa) - Coccidia[the product did not have the expected effect: coccidia]1.5%2,434
  17. Anorexia[not eating]1.3%2,101
  18. Underdose[less than the labelled amount was given]1.1%1,811
  19. Death1.1%1,732
  20. Depression[dull, quiet or withdrawn]1%1,696
  21. Emesis[vomiting]1%1,684
  22. Lack of efficacy (endoparasite) - whipworm[the product did not have the expected effect: whipworms]1%1,659
  23. Overdose[more than the labelled amount was given]1%1,649
  24. Underfilling, Package[a product quality report, not a sign in an animal]1%1,621
  25. Hard, clumping[a product quality report, not a sign in an animal]0.9%1,487
  26. Other abnormal test result NOS[abnormal laboratory result, type not specified]0.9%1,452
  27. Behavioural disorder NOS[behaviour change, type not specified]0.8%1,345
  28. Loose stool0.8%1,334
  29. Not eating0.8%1,294
  30. Ataxia[unsteady, uncoordinated movement]0.8%1,217

Top 30 of 2,003 coded terms (VeDDRA, the veterinary reporting dictionary; plain-language gloss in brackets). One report can list several terms. The ticks show how often the same term appears in a wider pool of reports; they describe the reports, and FDA cautions that such figures cannot be used to estimate risk or to compare one product with another. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand.

Outcomes and report types

Outcome recorded in the report

Recovered/Normal12.1%19,529
Recovered with Sequela10.2%16,445
Ongoing9%14,527
Died1.2%1,990
Euthanized0.6%920
Outcome Unknown37%59,734

What kind of report it was

Safety issue41.3%66,765
Lack of expected effectiveness47.1%76,062
Both safety and lack of expected effectiveness2.1%3,424
Manufacturing or product defect9.5%15,296
Other0.1%96

Coloured bar: reports naming ivermectin + pyrantel pamoate. Grey bar: all 1,357,245 reports in the database. Outcomes are the status at the time of the last report, as stated by the reporter; a report covering several animals can carry more than one outcome. FDA has not necessarily determined whether any drug played a part in any outcome.

Species and breeds in the reports

Species

Dog90.8%146,758
Cat0%66
Human exposure0%57
Other0%13
Other Canids0%8
Macaw0%3

Single-breed animals

Beagle2%3,251
Boxer1.6%2,522
Pit Bull1.5%2,383
Chihuahua1.4%2,184

Breed shares follow how common each breed is. Crossbred animals and reports with no breed stay in the species figure only.

Age, weight and route

Age of the animal

Under 1 year7.2%11,607
1 to 3 years34.6%56,004
4 to 7 years25.5%41,141
8 to 11 years14.2%22,976
12 years and over4.5%7,317
Age not given14%22,598

Weight of the animal

Under 5 kg (11 lb)6.6%10,609
5 to 9.9 kg (11–22 lb)13.3%21,539
10 to 24.9 kg (22–55 lb)28%45,323
25 to 44.9 kg (55–99 lb)34.5%55,834
45 kg and over (99 lb+)3.4%5,464
Weight not given14.2%22,874

Route of administration stated in reports: oral (142,321), topical (29), subcutaneous (15), other (11), intramuscular (8), ophthalmic (5).

In context

MeasureIvermectin + Pyrantel PamoateAll drugs containing ivermectinAll dog reportsAll reports
Reports161,643194,442985,6751,357,245
Share of that pool's reports naming this drug—83.1%14.9%11.9%
Classed serious, of reports stating it48.1%45.8%38.3%38.6%
Death or euthanasia recorded, per 1,000 reports18285563.8
Filed as lack of expected effectiveness (wholly or partly)49.2%——23%
Top term, share of reportsIneffective, heartworm larvae 21.4%19.1%7%—

The ivermectin pool is every report naming ivermectin alone or in any combination; this combination accounts for 83.1% of it. Shares are of reports, not of animals treated. The number of doses sold is not public, so none of these figures is a rate of occurrence, and differences between columns reflect which animals receive a drug and who reports as much as anything else.

Other ingredient sets sharing an ingredient

Active ingredientsReportsLatest 12 months
Pyrantel Pamoate + Sarolaner52,06610,626
Ivermectin20,072286
Ivermectin + Praziquantel + Pyrantel Pamoate8,999100
Afoxolaner + Moxidectin + Pyrantel Pamoate8,7694,349
Febantel + Praziquantel + Pyrantel Pamoate7,061415
Pyrantel Pamoate5,867250
Praziquantel + Pyrantel Pamoate5,037206
Ivermectin + Praziquantel3,38247
Lotilaner + Moxidectin + Praziquantel + Pyrantel Pamoate2,2612,231
Moxidectin + Pyrantel Pamoate + Sarolaner1,090344
Clorsulon + Ivermectin93419

Listed for navigation, ordered by report count. FDA states that these data "cannot be used to estimate the risk associated with the product or compare one drug or device product with another": drugs differ in formulation, in the animals they are given to, in sales volume and in years on the market. A report's ingredient field can be incomplete, so reports about one product may sit under more than one set.

FDA-approved products containing this combination (Green Book)

Reference information, not report statistics. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand. The list below is the FDA Green Book as of 30 Sep 2026; nothing on this page says which of these products, if any, a report concerned.

Trade nameActive ingredientsSponsorApproved forApplication
Heartgard PlusIvermectin, Pyrantel PamoateBoehringer Ingelheim Animal Health USA, Inc.DogsNADA 140-971
Iverhart Plus Flavored ChewablesIvermectin, Pyrantel PamoateVirbac AH, Inc.DogsANADA 200-302
Tri-Heart Plus Chewable TabletsIvermectin, Pyrantel PamoateDiamond Animal Health, Inc.DogsANADA 200-338

Species are the major species the Green Book search lists for the application ("—" where it lists another species or none). Approval dates are not part of the Green Book listing files and are not shown. Pioneer applications (NADA) come first, then generics (ANADA).

Questions about ivermectin + pyrantel pamoate reports

How many adverse event reports has FDA received for the combination ivermectin and pyrantel pamoate?

161,643 reports record a drug with the combination ivermectin and pyrantel pamoate as its active ingredients in the openFDA release of 28 Sep 2026, covering reports received through March 2026. 4,876 of them arrived in the latest 12 months.

Which brand do these reports concern?

That cannot be known from the public data. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand. The Green Book lists 3 approved applications with this combination; the reference list on this page names them without any counts.

What signs are reported most often?

ineffective, heartworm larvae (21.4%), lack of efficacy (endoparasite) - hookworm (15.5%), lack of efficacy (endoparasite) - heartworm (13.8%), vomiting (10.8%) and digestive tract disorder NOS (10.2%). These are the coded terms listed in reports; several can appear in one report, and a term's presence is not a finding that the drug was responsible.

Which species and breeds appear in these reports?

dog (90.8%), cat (0%) and human exposure (0%). Among single-breed animals the most frequent labels are Labrador Retriever, German Shepherd Dog, Golden Retriever and Beagle; popular breeds appear often in any drug's reports because there are more of them.

Are reports rising?

4,876 reports in the 12 months to March 2026, down 14% from 5,656 in the 12 months before. FDA posts reports quarterly with a delay of three to six months, so the newest months are incomplete and usually grow in later releases. Counts also move with sales, publicity and time on the market.

Do these reports show that ivermectin + pyrantel pamoate harms pets?

Report counts cannot show that. FDA states that "there is no certainty that the reported drug or device caused the adverse event" and that the event "may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources." FDA also notes that commonly used products may have more reports simply because more animals receive them.

Are these the side effects of ivermectin + pyrantel pamoate?

They are signs listed in reports, not an established list of side effects. The adverse reactions observed in studies are printed on each product's FDA-approved label, which a veterinarian can go through with you. This page is a record of what was reported to FDA.

How do I report a problem with an animal drug?

FDA asks owners and veterinarians to call the drug company first (the number is on the label); companies must pass reports to FDA. Reports can also go directly to FDA on Form FDA 1932a. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Animal & Veterinary adverse event bulk files released 28 Sep 2026, which hold reports FDA's Center for Veterinary Medicine received through 31 Mar 2026. openFDA masks brand and manufacturer names in these files, so drugs are counted by the active ingredients each record discloses and no figure is attributed to a brand, application or company. Ingredient names, and the separate reference lists of approved products, follow the FDA Green Book as of 30 Sep 2026. Drug entries are grouped by the active ingredients their unmasked ingredient field discloses; the application number that records also carry is not used. No report text, lot numbers or reporter details are published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.