I have had several questions around taking a dog back to the US and the new regulations. Having just returned to NYC with my three dogs (you all know Tequila), here are the details of what you need. I don't know about cats.

1) Health Certificate: This is not new. I have been able to get these from La Manz or Melaque. It basically says the dog is in good health. Further, if the dog is a mixed breed, the certificate must state that the dog is non brachycephalic
2) Chip
3) Rabies shot at least 1 month or longer before traveling back. The vet needs to certify this
4) CDC certificate. This is an online form that you fill out and then they send back an approval which you need to print.
5) Screw Worm Certificate. This is new. The closest I could find to get this certificate was in Manzanillo. It must be issued within 5 days of travel and requires that the vet inspect the dog. I went to the location below which did require an appointment.

Gilberto Isidro Arana Govea/Arana Pet Center
314 333 1199 or 314 892 5480
arana.petcenter@hotmail.com
It is very close to La Comer: Elias Zamora Verduzco S/N between Emiliano Zapata and Lazaro Cardenas

English is spoken there