In the treatment of horses suffering from the West Nile virus (WNV), vets have only a few choices besides supportive care. A novel WNV serum antibody product received conditional approval from the USDA in November 2004. Colorado Serum Company announced the product’s availability on Dec. 13, 2004.

Serum antibody products help animals that have been exposed to a disease by increasing the antibody level against the disease in the circulatory system. This enhances the animal’s ability to neutralize virus. The Colorado Serum product is the third WNV serum or plasma product to receive conditional approval from the USDA. Randall J. Berrier, DVM, director of Veterinary Services at Colorado Serum Company, explained that the new product is ready to use straight from the bottle (once it has been warmed to room or body temperature), and it does not require pre-treatment with non-steroidal anti-inflammatory drugs.

The serum antibody is developed from horses that have been hyperimmunized with inactivated WNV antigen and have developed high antibody levels to WNV. “Serum from these horses is collected, processed, pasteurized, tested and volume adjusted so that each bottle has a consistent level of protective antibodies,” said Berrier. “The dosage is 10 ml/100 pounds of body weight and is packaged in 100 ml bottles so that one bottle will treat a 1,000-pound horse.” Colorado Serum is also packaging WNV Serum Antibody in 50 ml bottles for more convenient dosaging in horses that weigh more or less than 1,000 pounds.

To receive a conditional license, the company had to prove the product’s purity, safety, and a