Pet Drug Reports

Milbemycin Oxime + Praziquantel (Interceptor Plus)adverse event reports that FDA received

Combination of 2 active ingredients

The name in brackets is a brand name with these active ingredients.

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.

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From May 2012 to June 2026, FDA received 33,672 adverse event reports that name a drug with milbemycin oxime and praziquantel as its active ingredients. Of the 33,672 reports, 31,521 (93.6%) are about dogs.

In January to March 2026, FDA received 492 reports that name this drug. The signs that appear in the largest number of the 33,672 reports are "Lack of efficacy (endoparasite) - heartworm", "Vomiting" and "Diarrhoea". A report is not proof that a drug caused a sign.

Reports that name this drug fell by 25.4% 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 dogs are 93.6% of the reports that name this drug, and 72.6% 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 425 to 492.
  • Dog: from 405 to 472.

January to March 2026 is the latest closed quarter in the data. In that quarter FDA received 492 reports that name milbemycin oxime + praziquantel: 472 dog, 0 cat, 0 horse, 20 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 33,672 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. Lack of efficacy (endoparasite) - heartworm[the product did not have the expected effect: heartworm]23.9%8,054 reports
  2. Vomiting19.2%6,465 reports
  3. Diarrhoea[diarrhea]7.3%2,462 reports
  4. Lack of efficacy (endoparasite) - hookworm[the product did not have the expected effect: hookworms]7.2%2,416 reports
  5. Lethargy[unusually tired or inactive]6.9%2,327 reports
  6. Ineffective, hooks[legacy FDA term: the product did not have the expected effect (hooks)]6.5%2,191 reports
  7. Unpalatable[legacy FDA term: the animal would not take it]5.2%1,754 reports
  8. Other abnormal test result NOS[abnormal laboratory result, type not specified]5%1,670 reports
  9. Lack of efficacy (endoparasite) - roundworm NOS[the product did not have the expected effect: roundworms]3.5%1,190 reports
  10. Lack of efficacy (roundworm)[the product did not have the expected effect: roundworms]3.3%1,117 reports
  11. Seizure NOS[seizure, type not specified]2.6%871 reports
  12. Not eating2.3%778 reports
  13. Behavioural disorder NOS[behaviour change, type not specified]2.2%730 reports
  14. Lack of efficacy (endoparasite) - tapeworm[the product did not have the expected effect: tapeworms]1.9%646 reports
Show the next 16 signs
  1. Weight gain1.7%576 reports
  2. Death1.6%541 reports
  3. Weight loss1.5%515 reports
  4. Lack of efficacy (endoparasite) - whipworm[the product did not have the expected effect: whipworms]1.5%498 reports
  5. Ataxia[unsteady, uncoordinated movement]1.4%487 reports
  6. Lack of efficacy (tapeworm)[the product did not have the expected effect: tapeworms]1.4%467 reports
  7. Ineffective, whips[legacy FDA term: the product did not have the expected effect (whips)]1.4%462 reports
  8. Lack of efficacy (bacteria) - Borrelia[the product did not have the expected effect: Borrelia (Lyme disease bacteria)]1.3%447 reports
  9. Decreased appetite1.2%409 reports
  10. Loose stool1.2%407 reports
  11. Drug dose omission[a scheduled administration was missed]1.2%398 reports
  12. Emesis (multiple)[vomiting more than once]1.2%389 reports
  13. Death by euthanasia[the animal was euthanized]1.1%364 reports
  14. Shaking1%350 reports
  15. Bloody diarrhoea[diarrhea with blood]0.9%318 reports
  16. Cough0.9%304 reports

The list shows 30 of 1,658 coded signs. A report is not proof that a drug caused a sign. Download all signs (CSV)

Reports by species

  • Dog93.6%31,521
  • Catunder 0.1%16
  • Human exposureunder 0.1%15
  • Otherunder 0.1%2
  • Other Canidsunder 0.1%1

The share is of all 33,672 reports that name milbemycin oxime + praziquantel. The other reports give a different species or no species.

Reports for each month, Jul 2021 to Jun 2026

Dog13,881 reports. Largest count in one month: 375 (Sep 2024)
Cat7 reports

No chart: no month has 5 or more reports.

Horse0 reports

No chart: no month has 5 or more reports.

Other or not given697 reports. Largest count in one month: 26 (Jul 2021)

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 milbemycin oxime + praziquantel, by the year in which FDA received them and by species
YearDogCatHorseOther or not givenAll species
20269390040979
20252,490101642,655
20243,096301403,239
20232,811101312,943
20222,950101403,091
20213,592202333,827
20204,325103364,662
20194,264002814,545
20183,432302743,709
20172,481202492,732
20161,111201441,257
20152500328
201430003
201310001
201210001

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/Normal21.4%7,209
  • Recovered with Sequela[recovered, with a lasting effect]0.2%69
  • Ongoing11.9%4,009
  • Died1.8%598
  • Euthanized1.1%364
  • Outcome Unknown57.4%19,317

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 33,672 reports that name milbemycin oxime + praziquantel.

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

Kind of report

  • Safety issue40.2%13,525
  • Lack of expected effectiveness39.4%13,261
  • Both safety and lack of expected effectiveness11.7%3,925
  • Manufacturing or product defect8.6%2,902
  • Other0.2%59

31,540 reports say if the event was serious. 11.4% 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 year13.6%4,564
  • 1 to 3 years35.3%11,888
  • 4 to 7 years21.5%7,238
  • 8 to 11 years13.2%4,432
  • 12 years and over5.4%1,834
  • Age not given11%3,716

Weight of the animal

  • Under 5 kg (11 lb)7.2%2,429
  • 5 to 9.9 kg (11 to 22 lb)13.4%4,505
  • 10 to 24.9 kg (22 to 55 lb)31.9%10,738
  • 25 to 44.9 kg (55 to 99 lb)32.3%10,865
  • 45 kg and over (99 lb and over)3.1%1,029
  • Weight not given12.2%4,106

Breed, where the report gives one breed

A breed with many animals has many reports.

Route in the report

  • Oral91.5%30,821
  • Topical0.1%19
  • Otherunder 0.1%10
  • Cutaneousunder 0.1%5
  • Rectalunder 0.1%4
  • Subcutaneousunder 0.1%4

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

  • Interceptor Plus

What the Green Book records give

Applications with an approval in force
1
Approved species
Dogs
Dose forms
Chewable Tablets
Routes
Oral
Sale
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.

Applications in the Green Book of 2 Nov 2026, pioneer applications (NADA) first
Brand nameActive ingredientsSponsorApproved speciesApplication
Interceptor PlusMilbemycin Oxime, PraziquantelElanco US Inc.DogsNADA 141-338

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. Milbemycin Oxime + Praziquantel: adverse event reports that FDA received. https://petdrugreports.com/drug/milbemycin-oxime-praziquantel/ 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 2,240 reports in the 12 months to June 2026. It received 3,001 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 33,672 reports received from May 2012 to June 2026, 40.2% are about a safety issue only. 51% are about a lack of expected effectiveness, alone or with a safety issue. 8.6% are about a defect of the product or its package.