Evaluation of efficacy of homeopathic and antibiotic treatment in scientific research and practice with focus on bovine mastitis

The use of homeopathy and antibiotics in treatment have the same goal: to cure a diseased individual. The first choice should be the most effective treatment and only a repeated treatment success will justify its use. If the chosen treatment is not effective, unnecessary suffering of diseased animals, spreading of disease or chronification of mastitis will be the result. Additionally, in case of antibiotic use, an ineffective use will select and promote the prevalence of multi-resistant bacteria in the environment, humans and animals as well as the loss of effectiveness of critically important antibiotics for treatment. Therefore, the aim of this thesis was to find out, if homeopathy might help to reduce or replace antibiotics. Consequently, homeopathy must be effective in general and in specific diseases, here in treatment of bovine mastitis, similarly or better compared to the standard antibiotic treatment. But how effective is homeopathic and antibiotic treatment according to scientific trials on bovine mastitis and is this reflected in the use and effectiveness in dairy practice? A systematic review on general efficacy of homeopathy applied in the treatment of food-producing animals with the aim to reduce antibiotics was performed involving 52 trials within peer-reviewed publications between 1981 and 2014 (paper I). Here, bovine mastitis was the main reason to apply homeopathy instead of antibiotics and the most scientific publications dealt with the efficacy when deployed. Therefore, efficacy and effectiveness of antibiotic and homeopathic treatment in bovine mastitis were evaluated and discussed based on peer-reviewed papers available focussing specifically on their scientific quality and outcome (paper II). On-farm effectiveness of antibiotic treatment in bovine mastitis and the value of record keeping was the topic of the last paper (III), investigated in a retrospective study with real-world data of 30 dairy farms, considering antibiotic consumption, treatment success and cost of mastitis on individual farm and cow level. The scientific literature (paper I) did not provide sufficient evidence of efficacy of homeopathy in farm animals on several diseases due to lack of scientific quality, repetition, and performance under various study conditions. Focussing on bovine mastitis (paper II), antibiotic studies testing efficacy in treatment provided efficacy in 47 % but had a low scientific quality and therefore did not provide valid results. Studies on efficacy of homeopathic treatment of bovine mastitis was positive for 42 % of the trials and had a better scientific quality compared to the former but failed to show efficacy especially in higher quality studies. In practice, treatment success of antibiotic treatment controlled by somatic cell count ranged between 18 – 59 % on the evaluated farms (paper III). The use of antibiotics for bovine mastitis showed a high variation in antibiotic consumption. About 13 – 53 % of all cows on the investigated farms received antibiotics due to mastitis during lactation with different antibiotic agents adding up from 5 to 17 within one treatment and total cost of mastitis (158 – 483€ per cow and year). The results indicated that using average or incomplete figures risks to lead to considerable misinterpretations. Antibiotics usage was remarkably high on most farms (and over 32 % of them categorized as ‘highest priority critically important antimicrobials’), while the poor treatment results signalled a need to improve treatment strategies to increase cure rates and reduce antibiotic consumption. Finally, when mastitis occurs, appropriate diagnostic including cyto-bacteriological milk samples should be performed to choose an appropriate treatment (applied according to current knowledge), followed by control of treatment outcome on cow and farm level. Any treatment needs to be justified by published results of high-quality studies (efficacy in science) followed by treatment monitoring on farm with outcome control (effectiveness in practice) on individual farms. A comparison between farms externally (benchmarking of treatment frequency, cure rates, disease incidence and costs) is necessary to motivate and support stakeholders (farmers, veterinarians, food retailers and politicians) to improve and change treatments, where necessary and to define treatment guidelines or protocols to reduce unnecessary antibiotic consumption. Antibiotic treatment of mastitis accompanied with insufficient control can be expected to result in a high antibiotic consumption. Thus, responsible use is not provided without on-going record keeping (treatment details and its outcome) and utilizing real-world data (somatic cell count, milk yield, conductivity etc.) including milk diagnostics (e.g., rapid on-farm milk tests on causing pathogen) to improve treatment strategies, animal health and welfare. The same is true for the use of homeopathy, which cannot be recommended according to the current scientific knowledge as it did not provide evidence for efficacy under optimized conditions and might even be lower under real-world conditions.