Notes and sources

Where every fact in this guide comes from

The other pages keep their sources out of the way so they stay easy to read. They all gather here. You do not need to read this page to look after your pet well, but it is here if you, or your vet, want to check a point.

How much weight each kind of source can carry

Not all sources are equal. This comparison shows what each kind can and cannot tell a pet owner.
Kind of source What it can tell you What it cannot
Federal rules and FDA pages How a medicine may reach an animal, and what FDA has said. Whether a given product helps your particular pet.
Approved drug labels The species, use and warnings that were reviewed for that one product. Anything about a different product that shares a word with it.
Studies in real pets What happened to animals living at home with their owners. A firm answer, when only a few animals took part.
Studies in lab animals Early clues about how a substance behaves in a body. What a product bought online will do in a pet.
Company announcements That a company says a study has begun. Results, which only a published study can show.

Dates matter here

A small stack of plain cloth-bound books with blank spines and a pair of reading glasses, a sleeping cat's tail curled at the edge of the table
Rules and databases change. Every dated fact here was checked on the day shown, and your vet can check what is current.

The checks behind this guide were made on September 30, 2026. That includes FDA's list of approved animal drug ingredients, its animal drug database, and searches of the medical literature.

A search that finds nothing is not proof that nothing exists. Where this guide says a study "was not found", that is exactly what it means.

Questions about pets that nobody can answer yet

Federal rules and FDA pages

State rules on the vet relationship

Studies in dogs and cats

Product testing and warnings about people

Other sources, named but not linked

Emergency services mentioned in this guide