) Equine Potomavac + Imrab is recommended for the vaccination of healthy horses against rabies and as an aid in the prevention of Potomac Horse Fever (equine monocytic ehrlichiosis) caused by E. risticii. Give 1 ml intramuscularly to horses 3 months of age or older. Give a booster dose 3 to 4 weeks later, using this product or Potomavac. Revaccinate annually with a single 1 ml dose of Equine Potomavac + Imrab. Order syringes and needles separately.