Fenbendazole (Panacur, Safe-Guard): adverse event reports that FDA received
Active ingredient
Also sold as: Panacur, Safe-Guard, Defendazole.
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.
Read this first. FDA says this about the data:
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 publishes these words. Source: Adverse Event Reports for Animal Drugs and Devices, read on . The data have the reports that FDA received through .
This page is not veterinary advice. For an animal that is ill, speak to a veterinarian.
Contacting a veterinarianHow to report to FDAFrom February 1987 to June 2026, FDA received 4,283 adverse event reports that name a drug with fenbendazole as its active ingredient. Of the 4,283 reports, 3,414 (79.7%) are about dogs. 204 reports are about cattle (4.8%).
In January to March 2026, FDA received 40 reports that name this drug. The signs that appear in the largest number of the 4,283 reports are "Vomiting", "Diarrhoea" and "Anorexia". A report is not proof that a drug caused a sign.
Reports that name this drug rose by 64.3% in the 12 months to June 2026, compared with the 12 months before. Reports for all animal drugs fell by 4.6% in the same periods. The newest months can get more reports in a later update. Reports about cats are 3.7% of the reports that name this drug, and 11% of all reports.
Since the last update of the FDA data
The site recorded an update of the FDA data on . FDA changed these counts for January to March 2026:
- All species: from 33 to 40.
- Dog: from 30 to 36.
January to March 2026 is the latest closed quarter in the data. In that quarter FDA received 40 reports that name fenbendazole: 36 dog, 3 cat, 0 horse, 1 other or not given.
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 4,283 reports that list the sign. One report can list more than one sign.
The sign that is in the largest number of the reports comes first.
- Vomiting27.2%1,167 reports
- Diarrhoea[diarrhea]15.3%657 reports
- Anorexia[not eating]13.1%560 reports
- Depression[dull, quiet or withdrawn]12.7%542 reports
- Death10.9%466 reports
- Lack of efficacy (endoparasite) - hookworm[the product did not have the expected effect: hookworms]7.6%326 reports
- Lethargy[unusually tired or inactive]4.6%199 reports
- Lack of efficacy (endoparasite) - tapeworm[the product did not have the expected effect: tapeworms]3.7%157 reports
- Other abnormal test result NOS[abnormal laboratory result, type not specified]3.5%151 reports
- Ineffective, hooks[legacy FDA term: the product did not have the expected effect (hooks)]3.1%131 reports
- Death by euthanasia[the animal was euthanized]2.8%122 reports
- Ataxia[unsteady, uncoordinated movement]2.7%114 reports
- Bloody diarrhoea[diarrhea with blood]2.6%110 reports
- Behavioural disorder NOS[behaviour change, type not specified]2.3%100 reports
Show the next 16 signs
- Accidental exposure[exposure that was not intended]2.2%95 reports
- Weakness2.2%93 reports
- Weight loss2.2%93 reports
- Vocalisation[crying out or unusual noise]2.1%92 reports
- Fever2.1%89 reports
- Hyperactivity2.1%89 reports
- Lack of efficacy (endoparasite) - roundworm NOS[the product did not have the expected effect: roundworms]2%86 reports
- Adipsia[not drinking]1.9%83 reports
- Emesis[vomiting]1.9%83 reports
- Digestive tract disorder NOS[digestive problem, type not specified]1.9%82 reports
- Dehydration1.9%80 reports
- Loose stool1.8%79 reports
- Trembling1.8%76 reports
- Lack of efficacy (endoparasite) - NOS[the product did not have the expected effect: target not specified]1.7%73 reports
- Cough1.6%70 reports
- Lack of efficacy - NOS[the product did not have the expected effect]1.6%69 reports
The list shows 30 of 1,091 coded signs. A report is not proof that a drug caused a sign. Download all signs (CSV)
Reports by species
The share is of all 4,283 reports that name fenbendazole. The other reports give a different species or no species.
Reports for each month, Jul 2021 to Jun 2026
No chart: no month has 5 or more reports.
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
| Year | Dog | Cat | Horse | Other or not given | All species |
|---|---|---|---|---|---|
| 2026 | 72 | 6 | 0 | 3 | 81 |
| 2025 | 154 | 17 | 0 | 8 | 179 |
| 2024 | 101 | 5 | 0 | 8 | 114 |
| 2023 | 86 | 6 | 0 | 13 | 105 |
| 2022 | 68 | 12 | 1 | 1 | 82 |
| 2021 | 114 | 5 | 1 | 4 | 124 |
| 2020 | 117 | 8 | 0 | 3 | 128 |
| 2019 | 109 | 5 | 0 | 4 | 118 |
| 2018 | 110 | 6 | 0 | 5 | 121 |
| 2017 | 103 | 8 | 0 | 4 | 115 |
| 2016 | 80 | 8 | 0 | 2 | 90 |
| 2015 | 48 | 2 | 0 | 2 | 52 |
| 2014 | 168 | 6 | 2 | 29 | 205 |
| 2013 | 273 | 14 | 10 | 70 | 367 |
| 2012 | 272 | 8 | 3 | 72 | 355 |
| 2011 | 217 | 7 | 9 | 71 | 304 |
| 2010 | 206 | 2 | 6 | 58 | 272 |
| 2009 | 231 | 5 | 10 | 44 | 290 |
| 2008 | 209 | 3 | 7 | 27 | 246 |
| 2007 | 171 | 5 | 7 | 22 | 205 |
| 2006 | 152 | 1 | 3 | 11 | 167 |
| 2005 | 139 | 5 | 3 | 22 | 169 |
| 2004 | 47 | 1 | 6 | 6 | 60 |
| 2003 | 9 | 2 | 3 | 7 | 21 |
| 2002 | 12 | 1 | 1 | 4 | 18 |
| 2001 | 14 | 1 | 2 | 3 | 20 |
| 2000 | 7 | 0 | 1 | 4 | 12 |
| 1999 | 17 | 2 | 6 | 17 | 42 |
| 1998 | 23 | 0 | 5 | 8 | 36 |
| 1997 | 13 | 2 | 2 | 9 | 26 |
| 1996 | 6 | 1 | 3 | 12 | 22 |
| 1995 | 17 | 1 | 2 | 13 | 33 |
| 1994 | 15 | 1 | 2 | 5 | 23 |
| 1993 | 1 | 0 | 0 | 6 | 7 |
| 1992 | 13 | 2 | 0 | 5 | 20 |
| 1991 | 0 | 0 | 0 | 7 | 7 |
| 1990 | 3 | 0 | 0 | 5 | 8 |
| 1989 | 9 | 0 | 3 | 9 | 21 |
| 1988 | 1 | 0 | 0 | 5 | 6 |
| 1987 | 7 | 0 | 0 | 5 | 12 |
2026 has the reports that FDA received through Jun 2026. Download the years (CSV)
What the reports record
Outcome at the time of the report
- Recovered/Normal9.3%397
- Recovered with Sequela[recovered, with a lasting effect]0.2%8
- Ongoing8.6%367
- Died13.3%568
- Euthanized1.2%50
- Outcome Unknown17.7%757
An outcome in a report is not proof that the drug caused it. The person who sends the report gives the outcome. Each share is of the 4,283 reports that name fenbendazole.
A report about more than one animal can have more than one outcome.
Kind of report
- Safety issue79.6%3,410
- Lack of expected effectiveness9.9%423
- Both safety and lack of expected effectiveness5.3%227
- Manufacturing or product defect5.2%223
- Other0%0
1,487 reports say if the event was serious. 41.2% of them have the serious flag. The person who sends the report sets the flag.
Show age, weight, breed and route
Age of the animal
- Under 1 year43.1%1,845
- 1 to 3 years19%814
- 4 to 7 years11.7%500
- 8 to 11 years5.4%231
- 12 years and over4%172
- Age not given16.8%721
Weight of the animal
- Under 5 kg (11 lb)24.7%1,056
- 5 to 9.9 kg (11 to 22 lb)16.6%710
- 10 to 24.9 kg (22 to 55 lb)20%855
- 25 to 44.9 kg (55 to 99 lb)13.7%586
- 45 kg and over (99 lb and over)6.1%263
- Weight not given19%813
Breed, where the report gives one breed
- Labrador Retriever5.7%244
- Pit Bull4%171
- Chihuahua3.3%143
- Greyhound3.3%142
- German Shepherd Dog3.1%131
- Domestic Shorthair1.9%81
- Golden Retriever1.8%79
- Boxer1.8%76
A breed with many animals has many reports.
Route in the report
- Oral77%3,297
- Topical0.3%11
- Subcutaneous0.2%8
- Respiratory (Inhalation)0.1%6
- Intramuscular0.1%4
- Ophthalmic0.1%3
Each bar is on a scale of 0 to 100%.
Approved animal drugs with this active ingredient (FDA Green Book)
This section is reference data. It has no report count.
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.
Brand names
- Panacur
- Safe-Guard
- Defendazole
What the Green Book records give
- Applications with an approval in force
- 11
- Approved species
- Cattle, Equids, Dogs, Goats, Swine, Cats (Wild Or Zoo), Chickens, Horses, Quail, Turkeys, Ursine (Bear), Wildlife
- Dose forms
- Top Dressing In Feed, Liquid (Suspension), Paste, Medicated Feed Block, Oral Suspension, Medicated Feed, Type A Medicated Article
- Routes
- Oral
- Sale
- OTC (over the counter), RX (prescription)
- Earliest approval date in the records
The species, dose forms and routes are the words of the Green Book records for all the applications together. One product can have fewer. The label of a product gives its approved use.
| Brand name | Active ingredients | Sponsor | Approved species | Application |
|---|---|---|---|---|
| Panacur Suspension 10% | Fenbendazole | Intervet, Inc. | Horses | NADA 104-494 |
| Panacur Granules 22.2% | Fenbendazole | Intervet, Inc. | Horses | NADA 111-278 |
| Panacur; Safe-guard | Fenbendazole | Intervet, Inc. | Horses | NADA 120-648 |
| Panacur C (OTC); Safe-Guard Canine (OTC); Panacur Granules 22.2% (Rx) | Fenbendazole | Intervet, Inc. | Dogs | NADA 121-473 |
| Safe-Guard; Panacur | Fenbendazole | Intervet, Inc. | Cattle, Goats | NADA 128-620 |
| Safe-Guard | Fenbendazole | Intervet, Inc. | Horses, Cattle, Swine, Turkeys | NADA 131-675 |
| Safe-Guard | Fenbendazole | Intervet, Inc. | Cattle | NADA 132-872 |
| Safe-Guard Type A Medicated Article | Fenbendazole | Intervet, Inc. | Cattle | NADA 137-600 |
| Safe-Guard; Safe-Guard EnProAl | Fenbendazole | Intervet, Inc. | Cattle | NADA 139-189 |
| Safe-Guard AquaSol | Fenbendazole | Intervet, Inc. | Swine, Chickens | NADA 141-449 |
| Defendazole | Fenbendazole | Norbrook Laboratories, Ltd. | Cattle, Goats | ANADA 200-831 |
| Purina Worm-A-Rest Litter Packapproval withdrawn | Fenbendazole | Virbac AH, Inc. | Swine | NADA 136-116 |
Next in the A to Z list
FDA pages for this drug
- 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 121-473The FDA record of the application for Panacur C (OTC), Safe-Guard Canine (OTC), Panacur Granules 22.2% (Rx).
- Green Book record of NADA 104-494The FDA record of the application for Panacur Suspension 10%.
- Green Book record of NADA 111-278The FDA record of the application for Panacur Granules 22.2%.
- Green Book record of NADA 120-648The FDA record of the application for Panacur, Safe-guard.
- Green Book record of NADA 128-620The FDA record of the application for Safe-Guard, Panacur.
- Green Book record of NADA 131-675The FDA record of the application for Safe-Guard.
- Animal Drugs @ FDAThe search page of the Green Book, the FDA list of approved animal drugs.
The site checked these addresses on . The links open in a new tab.
Cite this page
Pet Drug Reports. Fenbendazole: adverse event reports that FDA received. https://petdrugreports.com/drug/fenbendazole/ Source: FDA Center for Veterinary Medicine, openFDA Animal and Veterinary adverse event reports, export of . Reports received through .
Where the data come from
The counts come from the openFDA Animal and Veterinary adverse event files, export of 30 Oct 2026. The files have the reports that the FDA Center for Veterinary Medicine received through 26 Jun 2026. The files mask brand and manufacturer names. The site counts a drug by the active ingredients that each record gives, and gives no count to a brand, an application or a company. Ingredient names and the lists of approved products follow the FDA Green Book of 2 Nov 2026. The site does not use the application number that a record has.
The site does not publish report text, lot numbers or details of a reporter. FDA's record is the authority. See how the site counts reports, the data sources and the corrections page.
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 the brand names with this active ingredient.
- Do the reports show that the drug caused the signs?
No. 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 189 reports in the 12 months to June 2026. It received 115 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 4,283 reports received from February 1987 to June 2026, 79.6% are about a safety issue only. 15.2% are about a lack of expected effectiveness, alone or with a safety issue. 5.2% are about a defect of the product or its package.