Pet Drug Reports

Milbemycin Oxime (Interceptor, MilbeGuard)adverse event reports that FDA received

Active ingredient

Also sold as: Interceptor, MilbeGuard, Milbemite.

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 August 1990 to June 2026, FDA received 32,619 adverse event reports that name a drug with milbemycin oxime as its active ingredient. Of the 32,619 reports, 29,979 (91.9%) are about dogs. 406 reports are about cats (1.2%).

In January to March 2026, FDA received 110 reports that name this drug. The signs that appear in the largest number of the 32,619 reports are "Ineffective, heartworm larvae", "Vomiting" and "Diarrhoea". A report is not proof that a drug caused a sign.

Reports that name this drug fell by 4.5% 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 91.9% 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 100 to 110.
  • Dog: from 95 to 104.

January to March 2026 is the latest closed quarter in the data. In that quarter FDA received 110 reports that name milbemycin oxime: 104 dog, 4 cat, 0 horse, 2 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 32,619 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. Ineffective, heartworm larvae[legacy FDA term: the product did not have the expected effect (heartworm larvae)]36.2%11,815 reports
  2. Vomiting12%3,910 reports
  3. Diarrhoea[diarrhea]8.1%2,652 reports
  4. Lack of efficacy (endoparasite) - hookworm[the product did not have the expected effect: hookworms]7.3%2,372 reports
  5. Ineffective, ascarids NOS[legacy FDA term: the product did not have the expected effect (ascarids nos)]6.6%2,162 reports
  6. Depression[dull, quiet or withdrawn]5.9%1,929 reports
  7. Lack of efficacy (endoparasite) - whipworm[the product did not have the expected effect: whipworms]5.7%1,848 reports
  8. Lack of efficacy (endoparasite) - heartworm[the product did not have the expected effect: heartworm]3.6%1,189 reports
  9. Anorexia[not eating]3.6%1,167 reports
  10. Underfilling, Package[a product quality report, not a sign in an animal]2.8%901 reports
  11. Ataxia[unsteady, uncoordinated movement]2.3%753 reports
  12. Lethargy[unusually tired or inactive]2.3%753 reports
  13. Convulsion[seizure]2.3%749 reports
  14. Death2%655 reports
Show the next 16 signs
  1. Accidental exposure[exposure that was not intended]1.7%569 reports
  2. Emesis[vomiting]1.5%490 reports
  3. Lack of efficacy - NOS[the product did not have the expected effect]1.5%477 reports
  4. Trembling1.4%462 reports
  5. Tablets, Abnormal[a product quality report, not a sign in an animal]1.3%420 reports
  6. Death by euthanasia[the animal was euthanized]1.2%390 reports
  7. Bloody diarrhoea[diarrhea with blood]1.2%377 reports
  8. Pruritus[itching]1.1%360 reports
  9. Weight loss1.1%352 reports
  10. Seizure NOS[seizure, type not specified]1%341 reports
  11. Loose stool1%334 reports
  12. Other abnormal test result NOS[abnormal laboratory result, type not specified]1%330 reports
  13. Hypersalivation[drooling]1%312 reports
  14. Behavioural disorder NOS[behaviour change, type not specified]0.9%290 reports
  15. Fever0.8%267 reports
  16. Elevated alanine aminotransferase (ALT)[a liver enzyme above the normal range]0.8%266 reports

The list shows 30 of 1,480 coded signs. A report is not proof that a drug caused a sign. Download all signs (CSV)

Reports by species

  • Dog91.9%29,979
  • Cat1.2%406
  • Human exposure0.4%135
  • Other0.2%55
  • Ferretunder 0.1%3
  • Rabbitunder 0.1%3

The share is of all 32,619 reports that name milbemycin oxime. The other reports give a different species or no species.

Reports for each month, Jul 2021 to Jun 2026

Dog1,799 reports. Largest count in one month: 100 (Jun 2024)
Cat67 reports

No chart: no month has 5 or more reports.

Horse0 reports

No chart: no month has 5 or more reports.

Other or not given204 reports. Largest count in one month: 15 (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, by the year in which FDA received them and by species
YearDogCatHorseOther or not givenAll species
20261691104184
202532818031377
202446814025507
202329813035346
20223298052389
202145513085553
202054925041615
201965815058731
201879614054864
201784920056925
201683753045935
201537516080471
20141654060229
20135014044549
20122,218901032,330
20112,8751301293,017
20102,9011701393,057
20093,3331401253,472
20083,0811101213,213
20072,6462101442,811
20062,0032001082,131
20051,4562001131,589
20049281901501,097
20033338048389
200216511081257
200121110145357
20003167096419
19993501062413
19987030073
19974910050
19966310064
19952610027
19941600016
19932900029
19923800038
19916800068
19902700027

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/Normal7.3%2,383
  • Recovered with Sequela[recovered, with a lasting effect]0.4%119
  • Ongoing9%2,936
  • Died2.9%938
  • Euthanized0.5%156
  • Outcome Unknown9.6%3,132

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 32,619 reports that name milbemycin oxime.

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

Kind of report

  • Safety issue79.4%25,902
  • Lack of expected effectiveness12.5%4,092
  • Both safety and lack of expected effectiveness1.5%475
  • Manufacturing or product defect6.6%2,150
  • Other0%0

8,838 reports say if the event was serious. 35.5% 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 year8.5%2,757
  • 1 to 3 years35.7%11,639
  • 4 to 7 years26.6%8,680
  • 8 to 11 years14.9%4,870
  • 12 years and over5.3%1,730
  • Age not given9%2,943

Weight of the animal

  • Under 5 kg (11 lb)8.8%2,881
  • 5 to 9.9 kg (11 to 22 lb)13.2%4,314
  • 10 to 24.9 kg (22 to 55 lb)28.4%9,280
  • 25 to 44.9 kg (55 to 99 lb)35.9%11,721
  • 45 kg and over (99 lb and over)4.1%1,326
  • Weight not given9.5%3,097

Breed, where the report gives one breed

A breed with many animals has many reports.

Route in the report

  • Oral90.5%29,529
  • Auricular (Otic)0.8%253
  • Topical0.1%27
  • Otherunder 0.1%6
  • Intraocularunder 0.1%5
  • Intrauterineunder 0.1%5

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

  • Interceptor
  • MilbeGuard
  • Milbemite

What the Green Book records give

Applications with an approval in force
3
Approved species
Cats, Dogs
Dose forms
Flavored Tablets, Liquid (Solution), Tablet
Routes
Oral, Topical
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
InterceptorMilbemycin OximeElanco US Inc.Dogs, CatsNADA 140-915
Milbemite Otic SolutionMilbemycin OximeElanco US Inc.CatsNADA 141-163
MilbeGuardMilbemycin OximeCeva Sante AnimaleDogs, CatsANADA 200-629

Other pages with this ingredient

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: adverse event reports that FDA received. https://petdrugreports.com/drug/milbemycin-oxime/ Source: FDA Center for Veterinary Medicine, openFDA Animal and Veterinary adverse event reports, export of . Reports received through .

Embed this card on your site

Copy this code into your page. The card shows the figures above with their source. A line under the card links to this page.

How embedding works. It is free. Keep the link in the card and the link line under it.

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 383 reports in the 12 months to June 2026. It received 401 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 32,619 reports received from August 1990 to June 2026, 79.4% are about a safety issue only. 14% are about a lack of expected effectiveness, alone or with a safety issue. 6.6% are about a defect of the product or its package.