When transporting a horse from Alaska to the "Lower 48" you actually need 2 different health certificates.  The first certificate will authorize transport into and out of Canada (Canadian International Health Certificate).  The second health certificate authorizes transport from Alaska to your state of destination (Interstate Health Certificate).  Often these two requirements can be combined on the same document.  

Canadian International Health Certificate Requirements:

1. Coggins or Equine Infectious Anemia Test Completed within 6 months of your expected time of arrival at destination.
2. Canadian International Health Certificate (VS Form 17-140) completed by your Veterinarian and endorsed by a Federal Veterinarian.
3. USDA Statement of Health signed by your Veterinarian and endorsed by a Federal Veterinarian.  Do not use this document as the wording often changes

The process to complete an Equine International Health certificate (Canadian) requires pre-planning and time.  Allow a couple weeks to muddle through all the bureaucracy.

Interstate Health Certificate Requirements:

The Interstate Health Certificate depends on the Requirements of the state of destination.  The above link provides the information for State Import Requirements.

State of Alaska Import Requirements can be found on the State Veterinarians web page.

Note: Import / Export requirements change often - consult with your veterinarian prior to transporting your horse