Final answer:
Health records for small-animal interstate travel are essential and must be compliant with specific airline and DOT regulations, which may require submission 48 hours before travel. The exact validity period can vary and should be confirmed with the airline and state authorities.
Step-by-step explanation:
When traveling with small animals across state lines, health records are an essential part of the documentation needed to prove the well-being and suitability of the animal for travel. While the question regarding the exact validity period for these health records is not directly answered here, it is important to note that regulations pertaining to animal travel can be quite specific. For example, the Department of Transportation (DOT) has developed forms that certify an animal's health, behavior, and training. These forms are often required by airlines and may need to be submitted 48 hours before travel, while in some cases, they may also be required at the departure gate. For passengers with a Seeing Eye-certified or other officially trained dogs, providing these forms is typically straightforward. It is always recommended to check with specific airlines and state regulations regarding the validity period of health records as it can vary.