Lack of efficacy (bacteria) - Borrelia: in adverse event reports for animal drugs
Clinical sign, a VeDDRA term
In plain words: the product did not have the expected effect: Borrelia (Lyme disease bacteria).
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 October 2016 to June 2026, FDA received 12,926 adverse event reports for animal drugs that list this sign. That is 0.9% of the 1,378,761 reports that FDA received from January 1987 to June 2026. In the 12 months to June 2026, FDA received 2,791 reports that list this sign.
Of the 12,926 reports, 99.9% are about dogs. A report can list more than one sign and more than one drug. A report is not proof that a drug caused a sign.
By number of reports in all years, this sign is number 45 of 1,149 clinical signs with a page. Reports that list this sign fell by 11.3% 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 dogs are 99.9% of the reports that list this sign, and 72.6% of all reports.
Drug pages with reports that list this sign
The table has every drug page with 20 or more reports that list this sign, in order of name. No count decides which drug is in the table. The table has 22 drug pages.
| Active ingredients | Reports that list the sign |
|---|---|
| (S) - methoprene | 41 |
| Afoxolaner | 3,221 |
| Afoxolaner + Moxidectin + Pyrantel Pamoate | 887 |
| Carprofen | 43 |
| Doxycycline | 61 |
| Fluralaner | 1,153 |
| Gabapentin | 23 |
| Imidacloprid | 91 |
| Ivermectin | 23 |
| Ivermectin + Pyrantel Pamoate | 204 |
| Lotilaner | 681 |
| Lotilaner + Moxidectin + Praziquantel + Pyrantel Pamoate | 139 |
| Lufenuron + Milbemycin Oxime | 25 |
| Lufenuron + Milbemycin Oxime + Praziquantel | 21 |
| Maropitant | 22 |
| Milbemycin Oxime | 26 |
| Milbemycin Oxime + Praziquantel | 447 |
| Moxidectin + Pyrantel Pamoate + Sarolaner | 43 |
| Oclacitinib | 24 |
| Pyrantel Pamoate + Sarolaner | 6,472 |
| Sarolaner | 766 |
| Selamectin | 68 |
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. A report can name more than one drug.
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.
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
Ingredients, all combinations
The list has every active ingredient with 20 or more reports that list this sign, in order of name. It has 18 ingredients.
Reports by species
The share is of the 12,926 reports that list this sign. The sign is in 1.3% of all reports about the species dog. The sign is in 0% of all reports about the species cat.
Reports by month and by year
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.
| Year | Reports |
|---|---|
| 2026 | 1,501 |
| 2025 | 2,921 |
| 2024 | 3,074 |
| 2023 | 2,421 |
| 2022 | 1,969 |
| 2021 | 925 |
| 2020 | 104 |
| 2019 | 5 |
| 2018 | 1 |
| 2017 | 1 |
| 2016 | 4 |
What these reports record
Outcome at the time of the report
- Reports with this sign
- All reports
- Recovered/Normal2.6%331, All reports: 20.7%
- Recovered with Sequela[recovered, with a lasting effect]0.1%7, All reports: 2.3%
- Ongoing68.4%8,843, All reports: 17.4%
- Died0.2%23, All reports: 4.9%
- Euthanized0.4%52, All reports: 1.5%
- Outcome Unknown28.4%3,674, All reports: 22.7%
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 12,926 reports that list this sign.
Age of the animal
- Reports with this sign
- All reports
- Under 1 year8.8%1,132, All reports: 9.5%
- 1 to 3 years45.9%5,929, All reports: 23.9%
- 4 to 7 years25.9%3,354, All reports: 20.2%
- 8 to 11 years13.6%1,763, All reports: 15.4%
- 12 years and over4.1%533, All reports: 10.7%
- Age not given1.7%215, All reports: 20.3%
The outcome is for the full report, not for this sign only.
Next in the A to Z list of signs
- Laboured breathing
- Lack of coordination
- Lack of efficacy - NOS[the product did not have the expected effect]
- Lack of efficacy (bacteria) - Anaplasma[the product did not have the expected effect: Anaplasma bacteria]
- Lack of efficacy (bacteria) - Ehrlichia[the product did not have the expected effect: Ehrlichia bacteria]
- Lack of efficacy (bacteria) - NOS[the product did not have the expected effect: target not specified]
- Lack of efficacy (ectoparasite) - Demodex[the product did not have the expected effect: Demodex]
- Lack of efficacy (ectoparasite) - ear mite[the product did not have the expected effect: ear mites]
Cite this page
Pet Drug Reports. Lack of efficacy (bacteria) - Borrelia: adverse event reports for animal drugs. https://petdrugreports.com/reaction/lack-of-efficacy-bacteria-borrelia/ 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 counts the different spellings of one VeDDRA term together.
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 this sign
- What does this term mean in a report?
In plain words: the product did not have the expected effect: Borrelia (Lyme disease bacteria). It is a term from VeDDRA, the list of terms that FDA and drug companies use to code a report. The person who coded the report selected the term.
- How does the count of the latest 12 months compare with the 12 months before?
FDA received 2,791 reports in the 12 months to June 2026. It received 3,147 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.
- How many of these reports have a serious flag?
Of the 12,926 reports that say if the event was serious, 31.4% have the serious flag. The person who sends a report sets the flag.
- Does a drug in the table cause this sign?
The reports do not show that. A report can name more than one drug. 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