Poultry Import from Canada
Poultry imported from Canada into the United States are not required to be quarantined. However, the poultry must be accompanied by a veterinary health certificate issued within 30 days of importation and endorsed by a full-time salaried veterinarian of the Canadian government. The poultry must be inspected by a USDA veterinarian at the first U.S. port of entry.
An import permit is not required for poultry imported from Canada through a U.S. - Canadian land border port. However, if the poultry enters the United States through an air or sea port, an import permit (VS Form17-129) (fillable pdf 75kb) is required.
Health certificates that accompany Canadian live avian shipments must indicate that:
Poultry have been inspected prior to export by the veterinarian issuing the health certificate;
Poultry were either vaccinated for Newcastle disease at least 21 days prior to export and with a vaccine that does not contain any velogenic strains; OR were not vaccinated for Newcastle disease. (The health certificate should indicate which applies);
Poultry have not been vaccinated with a vaccine for any H5 or H7 subtype of avian influenza, and have not transited through regions/ premises where any HPAI subtype exists while en route to the United States;
No evidence of Newcastle disease or any communicable disease of poultry was found during the ninety (90) days preceding exportation from the premises of origin;
The premise of origin has not been under quarantine for any poultry disease during the preceding ninety (90) days;
As much as can be determined, the poultry were not exposed to communicable diseases of poultry during the ninety (90) days immediately prior to the inspection date;
Were shipped in new or appropriately sanitized containers prior to current use.
Couldn't find anything on getting back into Canada once the birds are in the US