Antimicrobial Therapy of Selected Organ Systems

Subconjunctival drug administration in horses

“…The subconjunctival route is the most frequently performed of the periocular drug delivery modalities in veterinary medicine. Traditionally, subconjunctival injections have been used to deliver drugs at increased concentrations and/or to produce sustained levels to the cornea and anterior segment (Bedford 1985; Dowling and Grahn 1998; Severin 1998). The route is particularly useful in acute situations where immediate high levels of a drug in the anterior segment is required (Matthews 2009).…”

“…The injection should be given under the bulbar conjunctiva to be effective. Injections into the palpebral conjunctiva are not suitable due to the rapid uptake of the drugs into the eyelid circulation and subsequent drug movement away from the eye (Dowling and Grahn 1998). Subconjunctival injections are generally well tolerated.…”

“…The solution is injected through a 25 or 26 gauge needle with a 1 ml syringe. In horses, volumes up to 1 ml are indicated (Severin 1998;Douglas et al 2008;Matthews 2009 493-495 doi: 10.1111/j.2042-3292.2011.00343.x due to the rapid uptake of the drugs into the eyelid circulation and subsequent drug movement away from the eye (Dowling and Grahn 1998). Subconjunctival injections are generally well tolerated.…”

“…In summary, subconjunctival injections are indicated in horses to enhance topical treatment when supplemental therapy is necessary or to provide an alternative route of administration if frequent topical application cannot be easily performed (Dowling and Grahn 1998;Donaldson et al 2012). The route is useful in emergency situations where immediate high levels of a certain drug are required.…”