Topical agents have been recognized as a important form of adjunct treatment to enhance resolution of various cutaneous skin
diseases, especially skin infections.
Third generation Tris-EDTA (Tricide—Molecular Therapeutics) is a chelating agent that removes divalent cations from the outer
membrane of bacteria and fungi, causing physical damage to ("poking holes" in) the membrane. Studies have shown that Tris-EDTA
is also effective in damaging the cell walls of yeast, which is useful when treating Malassezia otitis.1 It is completely nonirritating, is extremely stable, and can be stored for extended periods.
Tris-EDTA in combination with an appropriate antimicrobial can greatly increase efficacy, even against resistant microorganisms.2-4 It can be mixed with many injectable antimicrobial drugs and then used topically. At the time of use, the appropriate antibiotic
or antifungal can be added (e.g. 0.5 to 2 mg enrofloxacin, amikacin, or gentamicin added per ml Tricide; 0.1 to 0.5 mg fluconazole or miconazole/ml Tricide).
In this manner, it can be used to topically treat resistant infections or areas where more medication application (such as
flushing deep wounds) is needed.
SilvaKlenz (Molecular Therapeutics) is a skin and wound cleanser that does not contain alcohol, triclosan, or benzoyl chloride
and, thus, does not inhibit wound healing. As with Tricide, this topical product may have a potentiated antibacterial efficacy
and may be effective in breaking down bacterial biofilm (even methicillin-resistant Staphylococcus aureus biofilm), a significant barrier to effective treatment of infections. A sister product, Silvion (Molecular Therapeutics),
is a spray-on topical antimicrobial skin and wound moisturizer.
Tacrolimus (Protopic 0.1% ointment—Astellas) is an option for topical therapy of localized immune-mediated diseases such as
atopy, discoid lupus erythematosus, pemphigus erythematosus, and pemphigus foliaceus and for maintenance of patients with
perianal fistula. Although used orally in people, it has not been used orally in veterinary medicine because of the high frequency
of side effects.5 It has a similar mode of action to that of cyclosporine but is more potent. Inform owners that a transient increase in local
erythema and irritation can occur after starting therapy. Tacrolimus ointment is applied topically to the affected skin once
daily. Based on study data, it appears to be both safe and effective.6