Ivermectin: adverse event reports in all combinations

Drug pages with ivermectin

A report names a drug by its set of active ingredients. Each set with ivermectin that has a drug page is in the table, in order of name. The table has 5 sets.

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 195,736 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. Ineffective, heartworm larvae[legacy FDA term: the product did not have the expected effect (heartworm larvae)]19%37,192 reports
2. Lack of efficacy (endoparasite) - hookworm[the product did not have the expected effect: hookworms]13.5%26,344 reports
3. Lack of efficacy (endoparasite) - heartworm[the product did not have the expected effect: heartworm]12.7%24,811 reports
4. Vomiting11.9%23,258 reports
5. Digestive tract disorder NOS[digestive problem, type not specified]8.6%16,795 reports
6. Ineffective, ascarids NOS[legacy FDA term: the product did not have the expected effect (ascarids nos)]6.1%11,897 reports
7. Diarrhoea[diarrhea]5.2%10,173 reports
8. Cardiac disorder NOS[heart problem, type not specified]5.2%10,105 reports
9. Lack of efficacy - NOS[the product did not have the expected effect]4.6%8,937 reports
10. Tablets, Abnormal[a product quality report, not a sign in an animal]4.2%8,190 reports
11. Lethargy[unusually tired or inactive]3.9%7,684 reports
12. Ineffective, hooks[legacy FDA term: the product did not have the expected effect (hooks)]3.6%6,959 reports
13. Lack of efficacy (endoparasite) - roundworm NOS[the product did not have the expected effect: roundworms]2.6%5,161 reports
14. Containers, Damaged[a product quality report, not a sign in an animal]1.8%3,588 reports

Download all signs (CSV)

Reports by species

• Dog86.3%168,962
• Horse1.8%3,511
• Cattle1.3%2,461
• Cat0.6%1,095
• Human exposure0.4%739
• Sheep0.1%250

Reports for each month, Jul 2021 to Jun 2026

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

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

What the reports record

Each share of kind and age is of the 195,736 reports that name ivermectin.

FDA pages for this ingredient

• How to Report Animal Drug and Device Side Effects and Product ProblemsThe FDA page that tells an owner or a veterinarian how to send a report.
• Green Book record of NADA 128-409The FDA record of the application for Ivomec .27% Injection Grower And Feeder Pigs, Ivomec 1% Injection, Ivomec 1% Injection for Cattle And Swine, Ivomec Injection for Cattle.
• Green Book record of NADA 138-412The FDA record of the application for Heartgard 30, Heartgard Tablets.
• Green Book record of NADA 140-886The FDA record of the application for Heartgard Chewables For Dogs.
• Green Book record of NADA 140-971The FDA record of the application for Heartgard Plus.
• Green Book record of NADA 141-208The FDA record of the application for Advantage DUO.
• Green Book record of NADA 141-257The FDA record of the application for Iverhart MAX.
• Animal Drugs @ FDAThe search page of the Green Book, the FDA list of approved animal drugs.

The site checked these addresses on 2 Oct 2026. The links open in a new tab.

Cite this page

Pet Drug Reports. Ivermectin, all combinations: adverse event reports that FDA received. https://petdrugreports.com/ingredient/ivermectin/ Source: FDA Center for Veterinary Medicine, openFDA Animal and Veterinary adverse event reports, export of 30 Oct 2026. Reports received through 26 Jun 2026.

Where the data come from

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 4,953 reports in the 12 months to June 2026. It received 5,932 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 195,736 reports received from January 1987 to June 2026, 45.8% are about a safety issue only. 44.4% are about a lack of expected effectiveness, alone or with a safety issue. 9.8% are about a defect of the product or its package.