Veterinary clinical research database for homeopathy: placebo-controlled trials.

Background: Veterinary homeopathy has led a somewhat shadowy existence since its first introduction. Only in the last three decades has the number of clinical trials increased considerably. This literature is generally not well perceived, which may be partly a consequence of the diffuse and somewhat inaccessible nature of some of the relevant research publications. The Veterinary Clinical Research Database for Homeopathy (VetCR) was launched in 2006 to provide information on existing clinical research in veterinary homeopathy and to facilitate the preparation of systematic reviews.

Objective: The aim of the present report is to provide an overview of this first database on clinical research in veterinary homeopathy, with a special focus on its content of placebo controlled clinical trials and summarising what is known about placebo effects in animals.

Results: In April 2012, the VetCR database contained 302 data records. Among these, 203 controlled trials were identified: 146 randomised and 57 non-randomised. In 97 of those 203 trials, the homeopathic medical intervention was compared to placebo.

Comment: A program of formal systematic reviews of peer-reviewed randomised controlled trials in veterinary homeopathy is now underway; detailed findings from the program's data extraction and appraisal approach, including the assessment of trial quality (risk of bias), will be reported in due course.