Treatment of equine sarcoids

Below are abstracts and links to two articles on the treatment of equine sarcoids using either imiquimod or aciclovir cream:

Imiquimod is an immune response modifier with potent antiviral and antitumour activity. The objective of this pilot study was to evaluate the efficacy of an imiquimod 5% cream (Aldara™: 3M, Saint Paul, MN, USA) as a topical treatment for equine sarcoids. Fifteen horses with a total of 19 tumours were enrolled, including mixed (7), fibroblastic (5), flat (3), verrucous (2), and nodular (2) types. Baseline data included history, physical examination, tumour location, measurement and digital photography. Imiquimod was applied by the owners three times a week until complete resolution of the tumour or 32 weeks, whichever occurred first. Tumours were measured and photographed every 4 weeks. Treatment efficacy was defined as 75% or greater reduction of tumour size by the end of the trial. Four sarcoids were withdrawn from the study. Twelve of the remaining 15 tumours (80%) showed more than 75% reduction in size and nine (60%) totally resolved between 8 and 32 weeks. The most common adverse effects of exudation, erythema, erosions, depigmentation and alopecia were limited to the tumour and adjacent areas. The results suggest that topical imiquimod is a therapeutic option for the treatment of equine sarcoids, although more detailed studies are required to corroborate these initial findings.

Click here to be directed to the full study in Veterinary Dermatology.

Based on the anecdotally reported eradication of a sarcoid using aciclovir cream, the curative potential of this ointment was investigated in 22 sarcoid-affected horses referred to the Equine Clinic Tillysburg, Austria, between 2006 and 2009. Sarcoid disease was diagnosed by clinical examination and bovine papillomavirus types 1 and 2 from intact skin and tumour tissue. As nine horses had more than one lesion, a total of 47 sarcoids were treated by daily topical application of aciclovir 5 per cent cream for a period of two to six months; in four horses, surgical tumour ablation was performed before treatment. Disease parameters, including the tumour type, number, location and size, were recorded before and after aciclovir therapy. All 47 (100 per cent) of the sarcoids responded to treatment, with complete tumour regression observed for 32 (68 per cent) lesions and no recurrences reported thus far. Incomplete resolution was observed for 15 (32 per cent) lesions, probably due to their
thickness. Aciclovir is proposed to be routinely used for the treatment of mild-type sarcoids and as an adjuvant therapeutic agent in combination with surgery
 
Click here to be directed to the full study in Research Gate.