Pet Drug Reports

Drugs by active ingredient

Drug · single active ingredient

Levamisole Hydrochloride: adverse event reports

All products with this active ingredient · 17 FDA-approved applications in the Green Book

98reports naming this ingredient, 1987–20250% of all reports · about 3 a year
3reports, 12 months to March 20260 in the 12 months before
44.4%classed serious, as reportedof 9 reports stating it
59.2%record death or euthanasia, as reported58 reports
34.7%of reports concern sheep3.2% of all sheep reports

Between February 1987 and July 2025 FDA received 98 adverse event reports listing a drug with levamisole hydrochloride as the recorded active ingredient. The Green Book lists 17 FDA-approved applications with this single active ingredient.

openFDA masks the brand and manufacturer in every report, so these figures describe the ingredient across all products and cannot be attributed to a brand.

In the 12 months to March 2026, 3 reports named it, with none in the 12 months before. Recent months are provisional: fDA posts reports quarterly with a delay of three to six months, so the newest months are incomplete and usually grow in later releases. Over its whole reporting history that is about 3 reports a year and 0% of all 1,357,245 reports (3.2% of all sheep reports). How many animals received it is not published, so a count says nothing about how often a problem occurs per dose.

Reporters most often listed death (54.1%), hypersalivation (24.5%) and ataxia (13.3%). A report can list several signs, so shares add to more than 100%; 81 different terms appear across these reports. Death appears in 54.1% of these reports, a larger share than in the pooled reports for every drug containing levamisole hydrochloride (29.8%).

34.7% of reports concern sheep. Of reports that state seriousness, 44.4% were classed as serious, and 59.2% of all reports record a death or euthanasia as an outcome, as reported. FDA has not necessarily determined whether any drug played a part.

Monthly reports by species, five years

Dog0 · peak 1
2022202320242025
Cat0 · peak 1
2022202320242025
Horse0 · peak 1
2022202320242025
Other9 · peak 2
Nov 2021: 2Dec 2021: 1Apr 2022: 1May 2022: 1Sep 2022: 1Jun 2025: 1Jul 2025: 22022202320242025

Reports by the month FDA received them. Each panel has its own scale; the peak month is printed at the top right. The newest months are incomplete because FDA posts reports with a delay of three to six months.

Reports by year received

06111987: 719871988: 11989: 51990: 1119901991: 41992: 21993: 619931994: 61995: 21996: 1019961997: 11998: 21999: 119992000: 32001: 72003: 220032004: 22005: 32006: 220062007: 52008: 42012: 120122014: 12020: 12021: 320212022: 32025: 3

2025 covers reports received through March 2026 only.

Signs listed in reports

share of levamisole hydrochloride reports listing the termall drugs containing levamisole hydrochlorideall sheep reports

  1. Death54.1%53
  2. Hypersalivation[drooling]24.5%24
  3. Ataxia[unsteady, uncoordinated movement]13.3%13
  4. Depression[dull, quiet or withdrawn]13.3%13
  5. Trembling12.2%12
  6. Recumbency[lying down and unable or unwilling to rise]8.2%8
  7. Dyspnoea[difficulty breathing]7.1%7
  8. Convulsion[seizure]5.1%5
  9. Accidental exposure[exposure that was not intended]4.1%4
  10. Anaphylaxis[sudden severe allergic-type reaction]4.1%4
  11. Cough4.1%4
  12. Neurological signs NOS[NOS: not otherwise specified]4.1%4
  13. Unclassifiable adverse event[event that fits no dictionary term]4.1%4
  14. Diarrhoea[diarrhea]3.1%3
  15. Fever3.1%3
  16. PR-lung(s), lesion(s)[legacy FDA term: lesions found in the lungs]3.1%3
  17. Shaking3.1%3
  18. Tachypnoea[fast breathing]3.1%3
  19. Anorexia[not eating]2%2
  20. Behavioural disorder NOS[behaviour change, type not specified]2%2
  21. Cyanosis[bluish gums or skin from low oxygen]2%2
  22. Ineffective, strongyles[legacy FDA term: the product did not have the expected effect (strongyles)]2%2
  23. Lack of efficacy - NOS[the product did not have the expected effect]2%2
  24. No sign[no clinical sign was reported]2%2

Top 30 of 81 coded terms (VeDDRA, the veterinary reporting dictionary; plain-language gloss in brackets). One report can list several terms. The ticks show how often the same term appears in a wider pool of reports; they describe the reports, and FDA cautions that such figures cannot be used to estimate risk or to compare one product with another. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand.

Outcomes and report types

Outcome recorded in the report

Recovered/Normal2%2
Recovered with Sequela0%0
Ongoing0%0
Died59.2%58
Euthanized0%0
Outcome Unknown3.1%3

What kind of report it was

Safety issue96.9%95
Lack of expected effectiveness0%0
Both safety and lack of expected effectiveness0%0
Manufacturing or product defect3.1%3
Other0%0

Coloured bar: reports naming levamisole hydrochloride. Grey bar: all 1,357,245 reports in the database. Outcomes are the status at the time of the last report, as stated by the reporter; a report covering several animals can carry more than one outcome. FDA has not necessarily determined whether any drug played a part in any outcome.

Species and breeds in the reports

Species

Sheep34.7%34
Cattle20.4%20
Dog16.3%16
Goat9.2%9
Pig7.1%7
Human exposure6.1%6

Single-breed animals

Brahman2%2
Suffolk sheep2%2
Domestic1%1

Breed shares follow how common each breed is. Crossbred animals and reports with no breed stay in the species figure only.

Age, weight and route

Age of the animal

Under 1 year17.3%17
1 to 3 years14.3%14
4 to 7 years8.2%8
8 to 11 years1%1
12 years and over3.1%3
Age not given56.1%55

Weight of the animal

Under 5 kg (11 lb)0%0
5 to 9.9 kg (11–22 lb)3.1%3
10 to 24.9 kg (22–55 lb)12.2%12
25 to 44.9 kg (55–99 lb)8.2%8
45 kg and over (99 lb+)36.7%36
Weight not given39.8%39

Route of administration stated in reports: oral (76), topical (6), ophthalmic (2), subcutaneous (2).

In context

MeasureLevamisole HydrochlorideAll drugs containing levamisole hydrochlorideAll sheep reportsAll reports
Reports982451,0701,357,245
Share of that pool's reports naming this drug—40%3.2%0%
Classed serious, of reports stating it44.4%46.2%61.2%38.6%
Death or euthanasia recorded, per 1,000 reports591.833962963.8
Filed as lack of expected effectiveness (wholly or partly)0%——23%
Top term, share of reportsDeath 54.1%29.8%55%—

The levamisole hydrochloride pool is every report naming levamisole hydrochloride alone or in any combination; this single-ingredient set accounts for 40% of it. Shares are of reports, not of animals treated. The number of doses sold is not public, so none of these figures is a rate of occurrence, and differences between columns reflect which animals receive a drug and who reports as much as anything else.

Other ingredient sets sharing an ingredient

Active ingredientsReportsLatest 12 months
Doramectin + Levamisole Hydrochloride14761

Listed for navigation, 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": drugs differ in formulation, in the animals they are given to, in sales volume and in years on the market. A report's ingredient field can be incomplete, so reports about one product may sit under more than one set.

FDA-approved products containing levamisole hydrochloride (Green Book)

Reference information, not report statistics. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand. The list below is the FDA Green Book as of 1 Oct 2026; nothing on this page says which of these products, if any, a report concerned.

Trade nameActive ingredientsSponsorApproved forApplication
Ripercol L Bolus; Tramisol Cattle Wormer BolusLevamisole HydrochlorideZoetis Inc.CattleNADA 039-356
Ripercol L Soluble Drench PowderLevamisole HydrochlorideZoetis Inc.CattleNADA 039-357
Ripercol L; Tramisol Soluble Drench Powder for SheepLevamisole HydrochlorideZoetis Inc.SheepNADA 042-740
Ripercol L Wormer Oblets; Tramisol Sheep Wormer ObletsLevamisole HydrochlorideZoetis Inc.SheepNADA 042-837
Ripercol LLevamisole HydrochlorideZoetis Inc.SwineNADA 045-513
Levasole Cattle Wormer BolusLevamisole HydrochlorideIntervet, Inc.CattleNADA 091-826
TramisolLevamisole HydrochlorideZoetis Inc.SwineNADA 107-085
Levasole Soluble Pig WormerLevamisole HydrochlorideIntervet, Inc.SwineNADA 112-049
LevasoleLevamisole HydrochlorideIntervet, Inc.SheepNADA 112-050
Levamisole Soluble Drench Powder; Levasole; Levasole Soluble Drench Powder; Tramisol Soluble Drench PowderLevamisole HydrochlorideIntervet, Inc.Cattle, SheepNADA 112-051
Levasole Sheep Wormer Bolus; Tramisole Sheep Wormer Oblets TabletsLevamisole HydrochlorideIntervet, Inc.SheepNADA 112-052
Tramisol GelLevamisole HydrochlorideZoetis Inc.CattleNADA 126-237
ProhibitLevamisole HydrochlorideHuvepharma EOODCattle, SheepANADA 200-225
LevaMedLevamisole HydrochlorideBimeda Animal Health Ltd.SwineANADA 200-313
LevaMed Soluble Drench PowderLevamisole HydrochlorideBimeda Animal Health Ltd.Cattle, SheepANADA 200-386
Tramisol Type A Medicated Articleapproval voluntarily withdrawnLevamisole HydrochlorideFort Dodge Animal Health, Division of Wyeth, a wholly owned subsidiary of Pfizer, Inc.CattleNADA 044-015
Tramisol Type A Medicated Articleapproval voluntarily withdrawnLevamisole HydrochlorideFort Dodge Animal Health, Division of Wyeth, a wholly owned subsidiary of Pfizer, Inc.SwineNADA 045-455

Species are the major species the Green Book search lists for the application ("—" where it lists another species or none). Approval dates are not part of the Green Book listing files and are not shown. Pioneer applications (NADA) come first, then generics (ANADA).

Questions about levamisole hydrochloride reports

How many adverse event reports has FDA received for levamisole hydrochloride?

98 reports record a drug with levamisole hydrochloride as its active ingredient in the openFDA release of 28 Sep 2026, covering reports received through March 2026. 3 of them arrived in the latest 12 months.

Which brand do these reports concern?

That cannot be known from the public data. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand. The Green Book lists 17 approved applications with this ingredient alone; the reference list on this page names them without any counts.

What signs are reported most often?

death (54.1%), hypersalivation (24.5%), ataxia (13.3%), depression (13.3%) and trembling (12.2%). These are the coded terms listed in reports; several can appear in one report, and a term's presence is not a finding that the drug was responsible.

Which species and breeds appear in these reports?

sheep (34.7%), cattle (20.4%) and dog (16.3%). Among single-breed animals the most frequent labels are Brahman, Holstein-Friesian, Standardbred and Suffolk sheep; popular breeds appear often in any drug's reports because there are more of them.

Are reports rising?

3 reports in the 12 months to March 2026, with none in the 12 months before. FDA posts reports quarterly with a delay of three to six months, so the newest months are incomplete and usually grow in later releases. Counts also move with sales, publicity and time on the market.

Do these reports show that levamisole hydrochloride harms pets?

Report counts cannot show that. 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." FDA also notes that commonly used products may have more reports simply because more animals receive them.

Are these the side effects of levamisole hydrochloride?

They are signs listed in reports, not an established list of side effects. The adverse reactions observed in studies are printed on each product's FDA-approved label, which a veterinarian can go through with you. This page is a record of what was reported to FDA.

How do I report a problem with an animal drug?

FDA asks owners and veterinarians to call the drug company first (the number is on the label); companies must pass reports to FDA. Reports can also go directly to FDA on Form FDA 1932a. See the guide on how to report.

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. Drug entries are grouped by the active ingredients their unmasked ingredient field discloses; the application number that records also carry is not used. 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.