What Shots Are Intramuscular?

What Shots Are Intramuscular? Vaccines given IM (intramuscular) route: DTaP, DT, Hib, hepA, hepB Where are IM injections given in horses? Intramuscular (IM) injections are given deep into large muscles where the drug can be absorbed slowly. The most common location for an IM injection in the horse is the neck. Are horse vaccines intramuscular?