January 2020: adverse event reports received

5,295 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.

5,295reports received

5,478same month a year earlier-3%

6,041monthly average, preceding 12 months

73.3%concern dogscats 8.9%

FDA's database holds 5,295 adverse event reports received in January 2020, against 5,478 in the same month a year earlier and a monthly average of 6,041 over the preceding 12 months.

73.3% of the month's reports concern dogs, 8.9% 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 (763), moxidectin (576) and fluralaner (494), and the terms listed most often were vomiting (892), lack of efficacy (endoparasite) - heartworm (734) and lethargy (418). 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	763	14.4%
Moxidectin	576	10.9%
Fluralaner	494	9.3%
Milbemycin Oxime + Spinosad	444	8.4%
Milbemycin Oxime + Praziquantel	405	7.6%
Afoxolaner	306	5.8%
Sarolaner	171	3.2%
Oclacitinib	155	2.9%
Lufenuron + Milbemycin Oxime	123	2.3%
Melarsomine Dihydrochloride	115	2.2%
Imidacloprid + Moxidectin	106	2%
Insulin	106	2%
Selamectin	106	2%
Lotilaner	104	2%
Trilostane	104	2%

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

Vomiting16.8%892
Lack of efficacy (endoparasite) - heartworm[the product did not have the expected effect: heartworm]13.9%734
Lethargy[unusually tired or inactive]7.9%418
Diarrhoea[diarrhea]5.7%300
Ineffective, hooks[legacy FDA term: the product did not have the expected effect (hooks)]4.3%226
Product problem[a product quality report, not a sign in an animal]3.3%174
Seizure NOS[seizure, type not specified]3.2%171
Death3%160
Containers, Damaged[a product quality report, not a sign in an animal]2.7%142
Unpalatable[legacy FDA term: the animal would not take it]2.6%136
Lack of efficacy (endoparasite) - roundworm NOS[the product did not have the expected effect: roundworms]2.5%135
Lack of efficacy - NOS[the product did not have the expected effect]2.4%127
Behavioural disorder NOS[behaviour change, type not specified]2.2%118
Lack of efficacy (ectoparasite) - flea[the product did not have the expected effect: fleas]2.2%118
Not eating2.2%117

Single ingredients, pooled

Milbemycin Oxime20.2%1,070

Pyrantel Pamoate16.2%856

Ivermectin15.7%829

Moxidectin13%687

Praziquantel12.1%639

Fluralaner9.5%502

Spinosad9.5%501

Afoxolaner5.8%306

Sarolaner4.6%244

Lufenuron3.9%205

Selamectin3.3%176

Oclacitinib2.9%155

Species

Dog73.3%3,883

Cat8.9%473

Horse0.8%42

Other or not given16.9%897

Questions about January 2020

How many animal drug adverse event reports did FDA receive in January 2020?

5,295 reports are in the openFDA release of 28 Sep 2026. The same month a year earlier has 5,478.

Which drugs were named most often?

By active ingredient: ivermectin + pyrantel pamoate (763), moxidectin (576), fluralaner (494), milbemycin oxime + spinosad (444) and milbemycin oxime + praziquantel (405). Brands are masked in the public data.

Which signs were listed most often?

vomiting (892), lack of efficacy (endoparasite) - heartworm (734), lethargy (418), diarrhoea (300) and ineffective, hooks (226).

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 1 Oct 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.