April 1998: adverse event reports received

601 reports in the openFDA release of 28 Sep 2026

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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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601reports received

366same month a year earlier+64%

436monthly average, preceding 12 months

44.4%concern dogscats 7.5%

FDA's database holds 601 adverse event reports received in April 1998, against 366 in the same month a year earlier and a monthly average of 436 over the preceding 12 months.

44.4% of the month's reports concern dogs, 7.5% cats and 8.3% horses; the rest concern other species, exposed people, or give no species.

By active ingredient, the drugs named most often were medetomidine (188), moxidectin (79) and doramectin (77), and the terms listed most often were ineffective, sedation (99), vials, Leaking (61) and death (59). 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
Medetomidine	188	31.3%
Moxidectin	79	13.1%
Doramectin	77	12.8%
Pyrantel Tartrate	29	4.8%
Selegiline Hydrochloride	20	3.3%
Amitraz	17	2.8%
Ketamine Hydrochloride	17	2.8%
Sulfadimethoxine	14	2.3%
Tiletamine Hydrochloride + Zolazepam Hydrochloride	14	2.3%
Furazolidone	11	1.8%
Lufenuron + Milbemycin Oxime	8	1.3%
Butorphanol Tartrate	7	1.2%
Methylprednisolone Acetate	7	1.2%
Fenbendazole	5	0.8%
Fenthion	5	0.8%

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

Ineffective, sedation[legacy FDA term: the product did not have the expected effect (sedation)]16.5%99
Vials, Leaking[a product quality report, not a sign in an animal]10.1%61
Death9.8%59
Seal, Abnormal[a product quality report, not a sign in an animal]9%54
Pruritus[itching]7.5%45
Accidental exposure[exposure that was not intended]6.2%37
Unclassifiable adverse event[event that fits no dictionary term]5.5%33
Vomiting5%30
Alopecia NOS[hair loss, type not specified]4%24
Lack of efficacy (ectoparasite) - lice[the product did not have the expected effect: lice]4%24
Ataxia[unsteady, uncoordinated movement]3.8%23
Depression[dull, quiet or withdrawn]3.5%21
Anorexia[not eating]3.2%19
Convulsion[seizure]3.2%19
Sedation prolonged2.8%17

Single ingredients, pooled

Medetomidine31.3%188

Moxidectin13.1%79

Doramectin12.8%77

Pyrantel Tartrate4.8%29

Selegiline Hydrochloride3.3%20

Amitraz2.8%17

Ketamine Hydrochloride2.8%17

Sulfadimethoxine2.3%14

Tiletamine Hydrochloride2.3%14

Zolazepam Hydrochloride2.3%14

Lufenuron2.2%13

Furazolidone1.8%11

Species

Dog44.4%267

Cat7.5%45

Horse8.3%50

Other or not given39.8%239

Questions about April 1998

How many animal drug adverse event reports did FDA receive in April 1998?

601 reports are in the openFDA release of 28 Sep 2026. The same month a year earlier has 366.

Which drugs were named most often?

By active ingredient: medetomidine (188), moxidectin (79), doramectin (77), pyrantel tartrate (29) and selegiline hydrochloride (20). Brands are masked in the public data.

Which signs were listed most often?

ineffective, sedation (99), vials, Leaking (61), death (59), seal, Abnormal (54) and pruritus (45).

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.