Lack of efficacy - NOS: in adverse event reports for animal drugs

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 219 drug pages.

Ingredients, all combinations

The list has every active ingredient with 20 or more reports that list this sign, in order of name. It has 215 ingredients.

Reports by species

• Dog77.4%44,452
• Cat12.7%7,288
• Cattle5.6%3,223
• Horse2.6%1,522
• Other0.4%232
• Pig0.3%187

The share is of the 57,451 reports that list this sign. The sign is in 4.4% of all reports about the species dog. The sign is in 4.8% 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.

What these reports record

The outcome is for the full report, not for this sign only.

Next in the A to Z list of signs

• Labelled drug-drug interaction medication error
• Labels, Abnormal[a product quality report, not a sign in an animal]
• Laboured breathing
• Lack of coordination
• Lack of efficacy (bacteria) - Anaplasma[the product did not have the expected effect: Anaplasma bacteria]
• Lack of efficacy (bacteria) - Borrelia[the product did not have the expected effect: Borrelia (Lyme disease 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]

All clinical signs

Cite this page

Pet Drug Reports. Lack of efficacy - NOS: adverse event reports for animal drugs. https://petdrugreports.com/reaction/lack-of-efficacy-nos/ Source: FDA Center for Veterinary Medicine, openFDA Animal and Veterinary adverse event reports, export of 30 Oct 2026. Reports received through 26 Jun 2026.

Where the data come from

Questions about this sign

What does this term mean in a report?

In plain words: the product did not have the expected effect. 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 4,330 reports in the 12 months to June 2026. It received 4,441 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 54,599 reports that say if the event was serious, 36.7% 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