According to the letter to veterinary doctors, there will only be a limited supply of the Immiticide product available. The imported supply that will be available in the United States will be limited by the European supplier’s production capacity, and will not be able to fulfill the demand from the U.S. market. Merial is asking that doctors help to conserve the limited supply by using it only for dogs urgently in need of heartworm treatment.

The European product will begin arriving in the United States in October, and will be denoted by lot numbers that begin with the letters "MR" on the vial of freeze-dried cake. It will be available only from Merial directly through a restricted distribution program, and will not be available via distributors. The product will not available for purchase to stock clinic inventory.

"Merial and the IMMITICIDE manufacturer fully understand the critical need for the product and are continuing to work together to return to full supply as quickly as possible," said Merial spokesperson Natasha Mahanes.

The imported product, while not FDA-approved, comes from a European source that is approved for international markets. Because the European packaging does not meet U.S. regulatory requirements, Merial will include a copy of the U.S. Immiticide Package Inset with each shipment.

Veterinarians can call Customer Care at 1-888-MERIAL-1 (1-888-637-4251), option 1 to report their case and request the product.