Pet Drug Reports

Ingredients

Active ingredient · pooled across combinations

Lotilaner: adverse event reports, pooled

5 ingredient sets in reports · 4 FDA-approved applications in the Green Book

13,432reports naming the ingredient, 2015–20261% of all reports · about 1,260 a year
3,609reports, 12 months to March 20261,601 in the 12 months before
14.4%classed serious, as reportedall reports: 38.6%
85.9%of reports concern dogscat 6.4%

Lotilaner appears, alone or combined with other ingredients, in 13,432 reports in FDA's animal adverse event database (August 2015 to March 2026). The figures here pool all 5 ingredient sets that include it.

The Green Book lists 4 FDA-approved applications containing it. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand.

3,609 reports arrived in the 12 months to March 2026, up 125% from 1,601 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. That is about 1,260 reports a year over its reporting history and 1% of all reports.

Pooled across every set, the terms listed most often are vomiting (25%), diarrhoea (11.8%) and lethargy (10%). Many drugs combine several ingredients, and many reports list several drugs, so a term on this page may relate to any of them or to none.

Of reports that state seriousness, 14.4% were classed as serious (38.6% across the whole database); 2.6% record a death or euthanasia (6.4% overall). Ingredients used in older or sicker animals, or in anaesthesia and cancer care, carry higher shares for that reason alone.

Ingredient sets that include lotilaner

Active ingredients recorded for the drugReportsShare of this page's reportsLatest 12 months
Lotilaner11,34184.4%1,555
Lotilaner + Moxidectin + Praziquantel + Pyrantel Pamoate2,26116.8%2,231
Lotilaner + Milbemycin Oxime60%1
Lotilaner + Moxidectin + Praziquantel60%2
Lotilaner + Moxidectin + Pyrantel Pamoate10%1

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"; counts follow sales volume and years on the market. A report can list more than one set, so shares can add to more than 100%.

Signs listed in reports, pooled

share of lotilaner reports listing the termall reports in the database

  1. Vomiting25%3,355
  2. Diarrhoea[diarrhea]11.8%1,586
  3. Lethargy[unusually tired or inactive]10%1,343
  4. Unpalatable[legacy FDA term: the animal would not take it]6.7%906
  5. Other abnormal test result NOS[abnormal laboratory result, type not specified]6.3%848
  6. Lack of efficacy (ectoparasite) - tick NOS[the product did not have the expected effect: ticks]5.7%759
  7. Seizure NOS[seizure, type not specified]5.4%729
  8. Lack of efficacy (bacteria) - Borrelia[the product did not have the expected effect: Borrelia (Lyme disease bacteria)]5.3%707
  9. Lack of efficacy (ectoparasite) - flea[the product did not have the expected effect: fleas]4.7%637
  10. Behavioural disorder NOS[behaviour change, type not specified]4.4%593
  11. Lack of efficacy (endoparasite) - heartworm[the product did not have the expected effect: heartworm]4%538
  12. Not eating3.7%493
  13. Lack of efficacy (endoparasite) - hookworm[the product did not have the expected effect: hookworms]2.5%333
  14. Itching2.4%316
  15. Ataxia[unsteady, uncoordinated movement]2.3%310
  16. Emesis (multiple)[vomiting more than once]2.1%283
  17. Panting2%263
  18. Shaking1.9%250
  19. Anorexia[not eating]1.7%223
  20. Scratching1.6%216
  21. Death1.5%199
  22. Lack of efficacy (endoparasite) - roundworm NOS[the product did not have the expected effect: roundworms]1.5%196
  23. Lack of efficacy (bacteria) - Anaplasma[the product did not have the expected effect: Anaplasma bacteria]1.4%187
  24. Lack of efficacy (endoparasite) - tapeworm[the product did not have the expected effect: tapeworms]1.4%187
  25. Bloody diarrhoea[diarrhea with blood]1.4%186
  26. Emesis[vomiting]1.3%175
  27. Lack of efficacy (flea)[the product did not have the expected effect: fleas]1.3%174

Pooled across every ingredient set and every report that names the ingredient. One report can list several terms and several drugs; a term here may relate to any of them or to none.

Monthly reports by species, five years

Dog7,846 · peak 332
Apr 2021: 161May 2021: 120Jun 2021: 123Jul 2021: 155Aug 2021: 144Sep 2021: 101Oct 2021: 74Nov 2021: 91Dec 2021: 45Jan 2022: 52Feb 2022: 54Mar 2022: 87Apr 2022: 71May 2022: 116Jun 2022: 113Jul 2022: 110Aug 2022: 137Sep 2022: 88Oct 2022: 99Nov 2022: 80Dec 2022: 58Jan 2023: 74Feb 2023: 73Mar 2023: 64Apr 2023: 90May 2023: 145Jun 2023: 141Jul 2023: 109Aug 2023: 122Sep 2023: 97Oct 2023: 116Nov 2023: 81Dec 2023: 78Jan 2024: 71Feb 2024: 82Mar 2024: 99Apr 2024: 108May 2024: 122Jun 2024: 128Jul 2024: 127Aug 2024: 147Sep 2024: 112Oct 2024: 114Nov 2024: 85Dec 2024: 81Jan 2025: 63Feb 2025: 74Mar 2025: 106Apr 2025: 171May 2025: 261Jun 2025: 288Jul 2025: 313Aug 2025: 313Sep 2025: 284Oct 2025: 332Nov 2025: 221Dec 2025: 226Jan 2026: 204Feb 2026: 217Mar 2026: 2282022202320242025
Cat848 · peak 42
Apr 2021: 2Jun 2021: 4Jul 2021: 3Aug 2021: 11Sep 2021: 9Oct 2021: 10Nov 2021: 7Dec 2021: 10Jan 2022: 6Feb 2022: 5Mar 2022: 6Apr 2022: 3May 2022: 8Jun 2022: 20Jul 2022: 19Aug 2022: 30Sep 2022: 30Oct 2022: 16Nov 2022: 17Dec 2022: 10Jan 2023: 10Feb 2023: 13Mar 2023: 9Apr 2023: 6May 2023: 24Jun 2023: 21Jul 2023: 23Aug 2023: 27Sep 2023: 14Oct 2023: 21Nov 2023: 7Dec 2023: 4Jan 2024: 9Feb 2024: 4Mar 2024: 5Apr 2024: 17May 2024: 21Jun 2024: 16Jul 2024: 25Aug 2024: 30Sep 2024: 21Oct 2024: 14Nov 2024: 11Dec 2024: 6Jan 2025: 19Feb 2025: 9Mar 2025: 2Apr 2025: 14May 2025: 12Jun 2025: 32Jul 2025: 18Aug 2025: 26Sep 2025: 42Oct 2025: 11Nov 2025: 14Dec 2025: 26Jan 2026: 13Feb 2026: 12Mar 2026: 142022202320242025
Horse0 · peak 1
2022202320242025
Other755 · peak 40
Apr 2021: 13May 2021: 16Jun 2021: 11Jul 2021: 18Aug 2021: 15Sep 2021: 7Oct 2021: 7Nov 2021: 3Jan 2022: 3Feb 2022: 7Mar 2022: 10Apr 2022: 7May 2022: 12Jun 2022: 6Jul 2022: 8Aug 2022: 7Sep 2022: 6Oct 2022: 7Nov 2022: 6Dec 2022: 7Jan 2023: 8Feb 2023: 5Mar 2023: 8Apr 2023: 8May 2023: 6Jun 2023: 10Jul 2023: 11Aug 2023: 12Sep 2023: 9Oct 2023: 10Nov 2023: 6Dec 2023: 7Jan 2024: 4Feb 2024: 4Mar 2024: 11Apr 2024: 15May 2024: 21Jun 2024: 12Jul 2024: 9Aug 2024: 20Sep 2024: 13Oct 2024: 6Nov 2024: 6Dec 2024: 11Jan 2025: 8Feb 2025: 9Mar 2025: 13Apr 2025: 18May 2025: 25Jun 2025: 35Jul 2025: 33Aug 2025: 24Sep 2025: 40Oct 2025: 33Nov 2025: 24Dec 2025: 19Jan 2026: 21Feb 2026: 28Mar 2026: 172022202320242025

By month of receipt; each panel has its own scale. The newest months are incomplete because FDA posts reports with a delay of three to six months.

01,5793,1582015: 220152016: 120162017: 220172018: 57420182019: 1,30420192020: 1,81120202021: 1,44920212022: 1,32120222023: 1,46920232024: 1,58720242025: 3,15820252026: 7542026

Outcomes, report types and ages

Outcome recorded in the report

Recovered/Normal31.3%4,209
Recovered with Sequela0%6
Ongoing18.6%2,500
Died1.6%215
Euthanized1%137
Outcome Unknown39.9%5,362

What kind of report it was

Safety issue61.5%8,267
Lack of expected effectiveness19.4%2,608
Both safety and lack of expected effectiveness8.4%1,122
Manufacturing or product defect10.6%1,427
Other0.1%8

Species

Dog85.9%11,534
Cat6.4%859
Human exposure0.2%27
Pig0%1

Age of the animal

Under 1 year22.5%3,024
1 to 3 years27.9%3,751
4 to 7 years17.5%2,357
8 to 11 years10.9%1,464
12 years and over6.2%834
Age not given14.9%2,002

Coloured bar: reports naming lotilaner. Grey bar: all 1,357,245 reports. Outcomes are as stated by the reporter; FDA has not necessarily determined whether any product played a part.

In context

MeasureLotilanerAll reports
Reports13,4321,357,245
Latest 12 months against the 12 before+125%-5%
Classed serious, of reports stating it14.4%38.6%
Death or euthanasia recorded, per 1,000 reports26.163.8
Filed as lack of expected effectiveness (wholly or partly)27.8%23%

Shares of reports, not of animals treated: how many animals receive the ingredient is not public. Ingredients used in anaesthesia, cancer care or in old animals carry more serious outcomes in their reports for that reason alone.

FDA-approved products containing lotilaner (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 30 Sep 2026; nothing on this page says which of these products, if any, a report concerned.

Trade nameActive ingredientsSponsorApproved forApplication
CredelioLotilanerElanco US Inc.DogsNADA 141-494
Credelio CATLotilanerElanco US Inc.CatsNADA 141-528
Credelio QuattroLotilaner, Moxidectin, Praziquantel, Pyrantel PamoateElanco US Inc.DogsNADA 141-581
Credelio Quattro-CA1Lotilaner, Moxidectin, Praziquantel, Pyrantel PamoateElanco US Inc.DogsNADA 141-619

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 lotilaner reports

How many FDA adverse event reports mention lotilaner?

13,432 reports through March 2026, 3,609 of them in the latest 12 months, counting lotilaner alone and in combinations.

Which brands 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 reference list on this page names approved products containing lotilaner without any counts.

In which combinations is lotilaner reported?

Lotilaner (84.4% of these reports), Lotilaner + Moxidectin + Praziquantel + Pyrantel Pamoate (16.8% of these reports), Lotilaner + Milbemycin Oxime (0% of these reports), Lotilaner + Moxidectin + Praziquantel (0% of these reports) and Lotilaner + Moxidectin + Pyrantel Pamoate (0% of these reports).

What reactions are reported for lotilaner?

vomiting (25%), diarrhoea (11.8%), lethargy (10%), unpalatable (6.7%) and other abnormal test result NOS (6.3%). Shares are of reports naming the ingredient; one report can list several terms.

Which animals are these reports about?

dog (85.9%), cat (6.4%) and human exposure (0.2%).

Does a high count mean lotilaner is a problem ingredient?

A count 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." Widely used ingredients collect more reports because more animals receive them.

How do I report a problem?

Call the drug company using the number on the label, or send Form FDA 1932a to FDA. 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 30 Sep 2026. Ingredient names follow the Green Book; salts and forms are kept as FDA lists them. Drug entries are matched by the active ingredients their unmasked ingredient field discloses. 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.