Hunt continues for new mastitis cures
Extracts of Mexican lemon peel are one of the few substances which shows promising anti-microbial activity against mastitis in dairy cows.
The hunt for non-antimicrobial therapies is becoming urgent, due to increasing resistance to anti-microbials (antibiotics).
Veterinary researchers at the 29th World Buiatrics Congress in Dublin heard that Mexican researchers had detected potential antimicrobial activity for lemon peel extracts against Staphylococcus aureus bacteria, a frequent cause of mastitis which is increasingly resistant to antimicrobials.
The Congress heard the plant extract shows promising activity when used in teat dip or antimicrobial drugs for dairy cows.
However, Canadian researchers seeking to identify non-antimicrobial therapies told the congress no alternative therapies have consistently demonstrated efficacy for treatment of clinical mastitis, based on resolution of clinical signs, bacteriological cure, or milk production, in clinical trials.
They reviewed research papers, looking for clinical mastitis treatments in lactating dairy cows, other than antibiotics, that have demonstrated efficacy in clinical trials, observational studies, or experimental studies.
They said some phytotherapeutic products, or immunoglobulin-based products, need further investigation before conclusion on their efficacy.
Efficacy of oxytocin, with or without frequent milking out, was inconsistent in trials, and some detrimental effects were even reported.
Anti-inflammatory drugs demonstrated potential beneficial effects in experimental models, mainly on control of clinical signs associated with mastitis, but their positive effects have to be confirmed in randomised clinical trials.
US researcher Hubert Karreman said there are hardly any clinical studies with homeopathic remedies in dairy cows, but there are too many anecdotal successes to dismiss this mode of therapy, with many organic herds relying on homeopathic remedies to some degree.
However, results of German research presented at the Congress in Dublin said homeopathic treatments of clinical mastitis cannot be recommended, although they are widely used, for example on organic farms where use of antibiotics if greatly restricted.
From the University of Kassel, Witzenhausen, Germany, they said use of homeopathy in livestock is widespread, and becomes more and more popular with the aim to reduce use of antibiotics, especially in food-producing animals.
But their systematic review of peer-reviewed publications, to assess homeopathy in cattle, pigs and poultry, concluded that homeopathy to replace or reduce antibiotics cannot be recommended, unless evidence of efficacy is reproduced by Randomised Controlled Trials under modified conditions.
Another research team who presented at the Congress in Dublin said it is nearly impossible to predict the outcome of a homeopathic treatment, because farm conditions vary so much.
These EU-funded researchers studied 64 dairy farms in Germany, France and Spain, countries where homeopathic remedies are frequently used in dairy farming.
They found most farmers only had a poor level of awareness of the principles of homeopathy.
They said use of homeopathy by the farmers was often illegal, with 88% using human medicine products regularly without re-dedication by a veterinarian, and colchicine and/or aristolochia (forbidden substances) were found on 11 farms.
There was insufficient treatment documentation on over 80% of farms.
“Each farmer seems to have developed his/her own homeopathic treatment strategy without providing evidence with respect to the success of treatment,” said the researchers.
