Study: Antibiotic Administration Creates Significant Changes In Equine Gut's Microbiome

While humans receiving antibiotics are often prepared for intestinal upset, a horse given antibiotics is often not afforded the same preventative measures, despite the fact that antibiotics administration could cause disturbances with severe health consequences like diarrhea.

A new study from the Gluck Equine Research Center at the University of Kentucky has shown that even a short round of common antibiotics can change the gut microbiome. 

The research team used 24 horses, 12 mares and 12 geldings, that had not received antibiotics or dewormers in the previous three months and placed them into four groups: one that received potassium penicillin/gentamicin through intravenous injection; one group that received ceftiofur through intramuscular injection; one group that received trimethoprim sulphamethoxazole orally; and a control group.

The scientists evaluated fecal consistency, bacterial population count and performed a qPCR panel to detect disease-associated organisms before the treatment began, four times during treatment and one day after the treatment ended.

They found that all horses given antibiotics had softer manure than the control group; one horse developed severe diarrhea and was removed from the study. They also found that:

• All horses given antibiotics had a reduction in Lactobacillus spp. levels the day after treatment finished
• Horses given antibiotics were significantly more likely to test positive for C. difficile or C. perfringens

The researchers note that additional research into the consequences of antibiotic administration is needed.

Read more at Equine Science Update.