Treatment of clinically diagnosed equine sarcoid with a mistletoe extract (Viscum album austriacus)

J Vet Intern Med. Nov-Dec 2010;24(6):1483-9. doi: 10.1111/j.1939-1676.2010.0597.x. Epub 2010 Oct 12.


Background: Equine sarcoids (ES) are common, difficult to treat, and have high recurrence rates. Viscum album extracts (VAE) are used in human cancer treatment.

Hypothesis: That therapy with VAE (Iscador P) is effective in the treatment of ES.

Animals: Fifty-three horses (444 ES); 42 were treated with VAE or placebo as monotherapy; 11 were treated with VAE or placebo after selective excision of ES.

Methods: Prospective, randomised, blinded, clinical trial. Horses were randomly assigned to treatment (VAE; n=32) or control group (Placebo; n=21). One milliliter of VAE (Iscador P) in increasing concentrations from 0.1 to 20 mg/mL or physiological NaCl solution was given SC 3 times a week over 105 days. Number, localization, and type of the ES were documented over 12 months. A subset of 163 clinically diagnosed equine sarcoid (CDES) lesions (95 VAE, 68 Placebo) was evaluated in detail, considering clinical findings and tumor volume.

Results: No undesired adverse effects were observed except for mild edema at the injection site in 5 of 32 horses (16%). Complete or partial regression was observed in 13 horses of the VAE group (41%) and in 3 of the control horses (14%; P<.05). After VAE treatment, 48 of 95 CDES (67%) showed an improvement compared with 17 of 68 CDES in the control group (40%; P<.01). Twenty-seven CDES had disappeared completely in the VAE group (38%) compared with 9 CDES in the control group (13% NS).

Conclusions and clinical importance: VAE (Iscador P) represents a safe and effective treatment for CDES.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents, Phytogenic / therapeutic use*
  • Double-Blind Method
  • Horse Diseases / drug therapy*
  • Horses
  • Plant Extracts / chemistry
  • Plant Extracts / therapeutic use*
  • Prospective Studies
  • Skin Neoplasms / drug therapy
  • Skin Neoplasms / veterinary*
  • Viscum album / chemistry*


  • Antineoplastic Agents, Phytogenic
  • Plant Extracts