Equine On Antibiotics? Think Twice Before Probiotic Administration

Many equine caretakers administer probiotics to a horse who is being given antimicrobial drugs in an effort to support the horse’s microbiome, but this practice may have unintended negative consequences. According to EquiManagement, commercial products may contain live organisms with antimicrobial-resistant genes.

A study lead by Dr. Rachel Baumgardner of Washington State University’s College of Veterinary Medicine found that 47 of 50 probiotic products contained bacterial DNA that could lead to antimicrobial resistance (AMR); 94 percent of these had at least one AMR gene. The most-frequently found AMR genes were for tetracycline (68 percent) and sulfonamides (60 percent). Seven of the eight AMR genes were identified in multiple products.

The study team noted that probiotic administration encouraged the transfer of AMR genes to the horse’s gastrointestinal microbiota.

A study on humans completed by Jothan Suez of Johns Hopkins Bloomberg School of Public Health demonstrated that antibiotic treatment combined with the administration of probiotics caused a delay in the body’s return to its native microbiome. The microbiome returned to its original state more rapidly when probiotics were not administered.

Suez’s study team concluded that probiotic administration in conjunction with antibiotics delayed the return of a normal microbiome and that probiotic administration is not risk-free.

Read more at EquiManagement.