November 2018: adverse event reports received

4,978 reports in the openFDA release of 28 Sep 2026

Read this first · FDA's caveat, in its words

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

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Not veterinary advice. This site lists what was reported to FDA. For an animal that is unwell, contact a veterinarian.

4,978reports received

5,432same month a year earlier-8%

5,948monthly average, preceding 12 months

72.2%concern dogscats 11.4%

FDA's database holds 4,978 adverse event reports received in November 2018, against 5,432 in the same month a year earlier and a monthly average of 5,948 over the preceding 12 months.

72.2% of the month's reports concern dogs, 11.4% cats and 0.8% horses; the rest concern other species, exposed people, or give no species.

By active ingredient, the drugs named most often were ivermectin + pyrantel pamoate (769), fluralaner (569) and milbemycin oxime + spinosad (467), and the terms listed most often were vomiting (845), lethargy (427) and ineffective, hooks (332). Report volume has a seasonal shape, with more reports in the warmer months when parasite products are in heavier use.

The months around it

Drugs named most often, by active ingredient

Active ingredients recorded for the drug	Reports	Share of the month's reports
Ivermectin + Pyrantel Pamoate	769	15.4%
Fluralaner	569	11.4%
Milbemycin Oxime + Spinosad	467	9.4%
Afoxolaner	375	7.5%
Milbemycin Oxime + Praziquantel	261	5.2%
Moxidectin	213	4.3%
Sarolaner	199	4%
Selamectin	167	3.4%
Oclacitinib	161	3.2%
Lufenuron + Milbemycin Oxime	123	2.5%
Amoxicillin Trihydrate + Clavulanate Potassium	98	2%
Imidacloprid + Moxidectin	97	1.9%
Grapiprant	95	1.9%
Trilostane	91	1.8%
Melarsomine Dihydrochloride	87	1.7%

Ordered by report count, which follows how widely each drug was in use. FDA states that these data cannot be used to estimate risk or to compare one product with another. Brand and manufacturer names are masked by FDA in these records.

Signs listed most often

Vomiting17%845
Lethargy[unusually tired or inactive]8.6%427
Ineffective, hooks[legacy FDA term: the product did not have the expected effect (hooks)]6.7%332
Lack of efficacy (endoparasite) - heartworm[the product did not have the expected effect: heartworm]6.4%321
Diarrhoea[diarrhea]5.1%255
Seizure NOS[seizure, type not specified]4.1%206
Lack of efficacy (ectoparasite) - flea[the product did not have the expected effect: fleas]4%200
Death3.1%155
Lack of efficacy - NOS[the product did not have the expected effect]2.8%140
Anorexia[not eating]2.7%136
Unpalatable[legacy FDA term: the animal would not take it]2.7%133
Other abnormal test result NOS[abnormal laboratory result, type not specified]2.4%121
Ataxia[unsteady, uncoordinated movement]2.4%119
Lack of efficacy (flea)[the product did not have the expected effect: fleas]2.1%107
Not eating2.1%105

Single ingredients, pooled

Milbemycin Oxime19%948

Pyrantel Pamoate17.6%878

Ivermectin17.4%864

Fluralaner11.4%569

Spinosad11%550

Praziquantel10%496

Afoxolaner7.5%375

Moxidectin6.3%314

Sarolaner4%199

Lufenuron3.8%189

Selamectin3.4%167

Oclacitinib3.2%161

Species

Dog72.2%3,594

Cat11.4%569

Horse0.8%40

Other or not given15.6%775

Questions about November 2018

How many animal drug adverse event reports did FDA receive in November 2018?

4,978 reports are in the openFDA release of 28 Sep 2026. The same month a year earlier has 5,432.

Which drugs were named most often?

By active ingredient: ivermectin + pyrantel pamoate (769), fluralaner (569), milbemycin oxime + spinosad (467), afoxolaner (375) and milbemycin oxime + praziquantel (261). Brands are masked in the public data.

Which signs were listed most often?

vomiting (845), lethargy (427), ineffective, hooks (332), lack of efficacy (endoparasite) - heartworm (321) and diarrhoea (255).

Can the count for a month still change?

Yes. FDA posts reports quarterly with a delay of three to six months, so the newest months are incomplete and usually grow in later releases. Older months change little.

Does a busy month mean something went wrong that month?

Not by itself. The date is when FDA received the report, not when the event happened, and volume follows season, product launches and publicity. 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."

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. The month is the date FDA first received the report, not the date of the event. 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.