We are moving away from antibiotics. But is homeopathy a possible alternative? A meta-study looked at dozens of different trials since 1981 and concludes: the potential medical efficacy of homeopathy under certain conditions cannot be ruled out.
Homeopathy, developed in Western Europe, bases treatments on the Law of Similars or ‘like treating like’. In homeopathy, substances that would create adverse symptoms in a human or animal are extremely diluted. These dilute remedies are used to treat symptoms that the original product would have created.
Within the scientific community and veterinary practice, the use of homeopathy in food-producing animals is highly controversial. This doesn’t mean, these products are not used. For organic agriculture, the use of homeopathy is even promoted. But does it really work?
First review for food producing animals
For the first time, peer-reviewed publications conducted on the efficacy of homeopathy in food-producing animals have been reviewed. The review, published by the Department of Animal Nutrition and Animal Health, University of Kassel, Germany looked at a total number of 52 trials (including 34 trials with cattle, 12 with pigs and 6 with poultry) performed within 48 peer-reviewed publications in a quest to find evidence whether homeopathic remedies used for the prevention or treatment of diseases in livestock that are usually treated with antimicrobials. The studies considered in the review were done under European or comparable conditions (in respect to housing, breeds, intensive farming).
Main purpose is prevention of disease
The review showed that the main purpose of applying homeopathic remedies in clinical trials was prevention of disease (quoted in a total of 30 studies, including 6 studies aiming for good general health or growth promotion). Furthermore, 18 studies referred to the therapeutic treatment of diseases, while 4 studies focused on metaphylactic treatment (medication administered before the onset of clinical signs in the herd). The reason for using homeopathic remedies to treat disease was different for each species, see figure below.
In total, 54% (n=28) of the trials were able to confirm the efficacy of the homeopathic remedy administered, while 42% (n=22) found no benefit compared with the placebo or untreated group. 4% cent (n=2) had inconclusive results. When considering a single species, only homeopathic studies dealing with pigs were found to be frequently efficacious, while studies with cattle or poultry were seen to have a similar distribution of efficacious and non-efficacious treatment.
In order to provide information on cure rates, 18 out of 52 clinical trials which administered homeopathy exclusively for therapeutic reasons were further analysed. Only 10 of these trials gave information on cure rates, while 8 trials did not define cure rates at all. Instead, the effectiveness of the homeopathic remedy was evaluated on the basis of other criteria, for example, number of recurring treatments, mortality, duration of diarrhoea, fertility parameters, milk yield, and so on.
Cattle specific results
Altogether, 34 trials on cattle matched the selection criteria. The main focus (85%) was on dairy cows (n=29), the other studies dealt with calves (n=5). Homeopathy was proved efficacious in 15 studies, but no evidence was found in 18 studies and inconclusive results were returned for one of them.
Pig specific results
12 studies on pigs were identified. 9 trials found the homeopathic remedy to be effective, 2 could not prove the tested remedy to be efficacious and 1 had inconclusive results. The various outcomes seemed not to be related to the study design. Observational trials and open RCTs (Randomized Controlled Trials), as well as single- or double-blind RCTs, were performed with either efficacy or no efficacy or inconclusive results for the applied homeopathic remedy reported.
Poultry specific results
Only 6 studies were found dealing with homeopathic treatment in poultry production and they were performed exclusively on chickens. Efficacy of homeopathic treatment was proven in 4 studies out of the 6.
In a considerable number of studies, a significant higher efficacy was recorded for homeopathic remedies than for a control group. Therefore, the potential medical efficacy of homeopathy under certain conditions cannot be ruled out. However, this does not necessarily imply that homeopathic remedies are effective under different conditions.
The review revealed that all studies included were conducted under very specific conditions, but no trial was repeated in a comparable manner. Thus, the previous studies cannot be generalised and have to be regarded as single-case studies. The first priority when medically treating animals should always be to apply the most effective treatment or remedy and thus prevent unnecessary suffering of the animal, if only for the reasons of animal welfare. Due to the unknown level of effectiveness of on-farm homeopathy, this can only be achieved by the appropriate control and monitoring of treatment success in farm practice. Due to a lack of prognostic validity, replacing or reducing antibiotics with homeopathy currently cannot be recommended unless evidence of efficacy is reproduced by RCTs and proven in various farm practice conditions.