Ingredients

Ingredient sets that include ivermectin

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"; counts follow sales volume and years on the market. A report can list more than one set, so shares can add to more than 100%.

Signs listed in reports, pooled

share of ivermectin reports listing the termall reports in the database

1. Ineffective, heartworm larvae[legacy FDA term: the product did not have the expected effect (heartworm larvae)]19.1%37,191
2. Lack of efficacy (endoparasite) - hookworm[the product did not have the expected effect: hookworms]13.4%26,113
3. Lack of efficacy (endoparasite) - heartworm[the product did not have the expected effect: heartworm]12.5%24,394
4. Vomiting11.9%23,145
5. Digestive tract disorder NOS[digestive problem, type not specified]8.6%16,792
6. Ineffective, ascarids NOS[legacy FDA term: the product did not have the expected effect (ascarids nos)]6.1%11,897
7. Diarrhoea[diarrhea]5.2%10,122
8. Cardiac disorder NOS[heart problem, type not specified]5.2%10,105
9. Lack of efficacy - NOS[the product did not have the expected effect]4.6%8,927
10. Tablets, Abnormal[a product quality report, not a sign in an animal]4.1%8,038
11. Lethargy[unusually tired or inactive]3.9%7,637
12. Ineffective, hooks[legacy FDA term: the product did not have the expected effect (hooks)]3.6%6,959
13. Lack of efficacy (endoparasite) - roundworm NOS[the product did not have the expected effect: roundworms]2.6%5,094
14. Death1.8%3,546
15. Containers, Damaged[a product quality report, not a sign in an animal]1.8%3,544
16. Anorexia[not eating]1.7%3,379
17. Ataxia[unsteady, uncoordinated movement]1.7%3,338
18. Emesis[vomiting]1.7%3,264
19. Depression[dull, quiet or withdrawn]1.6%3,205
20. Seizure NOS[seizure, type not specified]1.6%3,096
21. Lack of efficacy (protozoa) - Coccidia[the product did not have the expected effect: coccidia]1.3%2,522
22. Underfilling, Package[a product quality report, not a sign in an animal]1.1%2,086
23. Overdose[more than the labelled amount was given]1%2,026
24. Underdose[less than the labelled amount was given]1%2,001
25. Behavioural disorder NOS[behaviour change, type not specified]1%1,936
26. Other abnormal test result NOS[abnormal laboratory result, type not specified]1%1,915
27. Accidental exposure[exposure that was not intended]1%1,869
28. Lack of efficacy (endoparasite) - whipworm[the product did not have the expected effect: whipworms]0.9%1,747
29. Not eating0.9%1,655
30. Hypersalivation[drooling]0.8%1,618

Pooled across every ingredient set and every report that names the ingredient. One report can list several terms and several drugs; a term here may relate to any of them or to none.

Monthly reports by species, five years

By month of receipt; each panel has its own scale. The newest months are incomplete because FDA posts reports with a delay of three to six months.

Outcomes, report types and ages

Coloured bar: reports naming ivermectin. Grey bar: all 1,357,245 reports. Outcomes are as stated by the reporter; FDA has not necessarily determined whether any product played a part.

In context

Shares of reports, not of animals treated: how many animals receive the ingredient is not public. Ingredients used in anaesthesia, cancer care or in old animals carry more serious outcomes in their reports for that reason alone.

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. Ingredient names follow the Green Book; salts and forms are kept as FDA lists them. Drug entries are matched by the active ingredients their unmasked ingredient field discloses. 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.