Pet Drug Reports

Praziquantel + Pyrantel Pamoate (Virbantel, Worm X Plus)adverse event reports that FDA received

Combination of 2 active ingredients

Also sold as: Virbantel, Worm X Plus, Drontal.

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 FDA

From December 1995 to June 2026, FDA received 5,092 adverse event reports that name a drug with praziquantel and pyrantel pamoate as its active ingredients. Of the 5,092 reports, 3,680 (72.3%) are about dogs. 1,260 reports are about cats (24.7%).

In January to March 2026, FDA received 62 reports that name this drug. The signs that appear in the largest number of the 5,092 reports are "Vomiting", "Lethargy" and "Diarrhoea". A report is not proof that a drug caused a sign.

Reports that name this drug fell by 13.1% 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 24.7% 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 48 to 62.
  • Dog: from 32 to 38.
  • Other species or species not given: from 0 to 7.

January to March 2026 is the latest closed quarter in the data. In that quarter FDA received 62 reports that name praziquantel + pyrantel pamoate: 38 dog, 17 cat, 0 horse, 7 other or not given.

All updatesFeed of updates (RSS)

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 5,092 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.

  1. Vomiting38.1%1,941 reports
  2. Lethargy[unusually tired or inactive]18.4%936 reports
  3. Diarrhoea[diarrhea]12.4%632 reports
  4. Ataxia[unsteady, uncoordinated movement]10.6%542 reports
  5. Anorexia[not eating]6.3%323 reports
  6. Not eating5.6%283 reports
  7. Death4.8%244 reports
  8. Emesis[vomiting]4.3%220 reports
  9. Depression[dull, quiet or withdrawn]4.3%219 reports
  10. Bloody diarrhoea[diarrhea with blood]4.1%207 reports
  11. Behavioural disorder NOS[behaviour change, type not specified]4%202 reports
  12. Emesis (multiple)[vomiting more than once]3.3%168 reports
  13. Loose stool3.2%164 reports
  14. Shaking3%152 reports
Show the next 16 signs
  1. Not drinking2.8%141 reports
  2. Overdose[more than the labelled amount was given]2.7%138 reports
  3. Lack of efficacy (endoparasite) - tapeworm[the product did not have the expected effect: tapeworms]2.7%136 reports
  4. Drug administration error2.4%120 reports
  5. Vocalisation[crying out or unusual noise]2.3%119 reports
  6. Hypersalivation[drooling]2.3%115 reports
  7. Decreased appetite2.2%111 reports
  8. Seizure NOS[seizure, type not specified]2%102 reports
  9. Accidental exposure[exposure that was not intended]1.8%90 reports
  10. Panting1.7%88 reports
  11. Underdose[less than the labelled amount was given]1.7%86 reports
  12. Lack of efficacy (endoparasite) - hookworm[the product did not have the expected effect: hookworms]1.6%82 reports
  13. Weakness1.6%81 reports
  14. Weight loss1.6%80 reports
  15. Death by euthanasia[the animal was euthanized]1.5%76 reports
  16. Other abnormal test result NOS[abnormal laboratory result, type not specified]1.4%71 reports

The list shows 30 of 1,011 coded signs. A report is not proof that a drug caused a sign. Download all signs (CSV)

Reports by species

  • Dog72.3%3,680
  • Cat24.7%1,260
  • Human exposure0.6%30
  • Otherunder 0.1%2
  • Cattleunder 0.1%1

The share is of all 5,092 reports that name praziquantel + pyrantel pamoate. The other reports give a different species or no species.

Reports for each month, Jul 2021 to Jun 2026

Dog897 reports. Largest count in one month: 28 (Aug 2022)
Cat246 reports. Largest count in one month: 13 (Feb 2024)
Horse0 reports

No chart: no month has 5 or more reports.

Other or not given73 reports. Largest count in one month: 5 (Nov 2022)

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
Reports that name praziquantel + pyrantel pamoate, by the year in which FDA received them and by species
YearDogCatHorseOther or not givenAll species
202664270798
202515850010218
202417655015246
202318444012240
202221047023280
202121950010279
202023256015303
20192056505275
20182127001283
2017184103011298
2016729505172
20151895704250
201427270014356
20133738407464
20123255304382
20112533905297
20102094202253
20091044400148
200831170048
20078300038
20060130013
20050220022
20040160016
20030120012
20020290231
20010110011
20000130013
19990150015
19980130013
19970110011
199606006
199501001

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/Normal33.2%1,691
  • Recovered with Sequela[recovered, with a lasting effect]0.3%14
  • Ongoing4.5%230
  • Died5.4%277
  • Euthanized1.2%63
  • Outcome Unknown39.4%2,007

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 5,092 reports that name praziquantel + pyrantel pamoate.

A report about more than one animal can have more than one outcome.

Kind of report

  • Safety issue88%4,480
  • Lack of expected effectiveness5.2%266
  • Both safety and lack of expected effectiveness3.9%201
  • Manufacturing or product defect2.8%144
  • Otherunder 0.1%1

4,202 reports say if the event was serious. 37.5% 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 year34.5%1,758
  • 1 to 3 years23.4%1,194
  • 4 to 7 years15.2%774
  • 8 to 11 years9.6%487
  • 12 years and over6.9%351
  • Age not given10.4%528

Weight of the animal

  • Under 5 kg (11 lb)38.8%1,975
  • 5 to 9.9 kg (11 to 22 lb)21.9%1,116
  • 10 to 24.9 kg (22 to 55 lb)16.2%824
  • 25 to 44.9 kg (55 to 99 lb)9%457
  • 45 kg and over (99 lb and over)1.7%86
  • Weight not given12.5%634

Breed, where the report gives one breed

A breed with many animals has many reports.

Route in the report

  • Oral92.5%4,708
  • Topical0.2%11
  • Ophthalmic0.1%3
  • Subcutaneousunder 0.1%2
  • Epiduralunder 0.1%1

Each bar is on a scale of 0 to 100%.

Approved animal drugs with these active ingredients (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

  • Virbantel
  • Worm X Plus
  • Drontal

What the Green Book records give

Applications with an approval in force
2
Approved species
Dogs, Cats
Dose forms
Chewable Tablets, Tablet, Tablet (Chewable)
Routes
Oral
Sale
OTC (over the counter)
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.

Applications in the Green Book of 2 Nov 2026, pioneer applications (NADA) first
Brand nameActive ingredientsSponsorApproved speciesApplication
Drontal TabletsPraziquantel, Pyrantel PamoateElanco US Inc.CatsNADA 141-008
Virbantel; Worm X PlusPraziquantel, Pyrantel PamoateVirbac AH, Inc.DogsNADA 141-261

Other pages with one of these ingredients

A report names a drug by its set of active ingredients. Each set has its own page. The list is in order of name.

Next in the A to Z list

All drugs by active ingredient. Brand names A to Z

FDA pages for this drug

The site checked these addresses on . The links open in a new tab.

Cite this page

Pet Drug Reports. Praziquantel + Pyrantel Pamoate: adverse event reports that FDA received. https://petdrugreports.com/drug/praziquantel-pyrantel-pamoate/ Source: FDA Center for Veterinary Medicine, openFDA Animal and Veterinary adverse event reports, export of . Reports received through .

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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 these active ingredients.

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 206 reports in the 12 months to June 2026. It received 237 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 5,092 reports received from December 1995 to June 2026, 88% are about a safety issue only. 9.2% are about a lack of expected effectiveness, alone or with a safety issue. 2.8% are about a defect of the product or its package.