There’s some good info at this link: https://www.aphis.usda.gov/pet-travel/us-to-another-country-export/pet-travel-united-states-mexico#:~:text=on%20this%20page.-,Dogs%20and%20Cats,wounds%20in%20a%20healing%20process.

Even though Mexico doesn’t require a health certificate right now, getting back into the US is more strict than it was last year (even if it’s just a connecting flight at a US airport).

https://www.cdc.gov/importation/dogs/rabies-free-low-risk-countries.html

You should check with your local veterinarian and make sure you’re up to date before leaving home.