POTOMAVAC is recommended for the vaccination of healthy horses, three months of age and older, as an aid in the prevention of Potomac Horse Fever (equine monocytic ehrlichiosis) caused by E. risticii. Contains gentamicin as a preservative. Supplied as 5 single dose vials or as a 10 dose bottle. Needles and syringes sold separately. Equine vaccine Protects against Equine Monocytic Ehrlichiosis Safe for horses 3 months of age and older All vaccines are shipped Express 1-2 Days. A $29.95 flat rate fee is charged for all orders containing vaccines. Someone should be present to sign for and receive the vaccine order when it ships to you. For more shipping info click here. NOTE: This item cannot be shipped to Minnesota, Canada and P.O. Boxes. Use must be approved by your veterinarian.