UK Researcher Explores New Treatments to Prevent Foal Loss in Mares

“In many cases, losing a pregnancy represents the loss of an entire breeding season, substantial veterinary and management expenses and uncertainty about a mare’s future reproductive performance,” Yosra Helmy, Ph.D., an associate professor of veterinary science at the University of Kentucky Martin-Gatton College of Agriculture, Food and Environment, reported.

That realization has prompted a new research effort at the institution to develop innovative chemical compounds that protect pregnant mares from bacterial infections causing foal loss. Helmy has received funding from the American Quarter Horse Foundation to investigate whether small molecules can control specific pathogens responsible for equine abortions while addressing growing concerns about antibiotic resistance.

Key Clinical Takeaways:

• University of Kentucky researchers are developing novel small-molecule therapeutics to prevent bacterial infections and foal loss in pregnant mares.
• The project specifically targets pathogens such as Streptococcus zooepidemicus, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae that cause ascending placentitis.
• Work is funded by the American Quarter Horse Foundation and supported by the National Institutes of Health under Award Number P20GM130456.

The Pathogens Driving Ascending Placentitis in Mares

The research focuses on finding alternatives to conventional antibiotics, which do not always successfully treat infections in the equine reproductive tract. One of the primary targets is Streptococcus equi subspecies zooepidemicus, commonly known as Streptococcus zooepidemicus. While this bacterium can normally be found in horses without causing illness, it can enter the reproductive tract under certain conditions and cause serious infections.

Other bacteria including Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae can cause similar reproductive problems. These pathogens trigger ascending placentitis, an infection that occurs when bacteria enter the mare’s reproductive tract and spread to the placenta. When the placenta becomes infected and inflamed, the developing foal may not receive adequate oxygen and nutrients, leading to premature birth or pregnancy loss.

Limitations of Conventional Equine Antibiotic Treatments

Veterinarians commonly rely on antibiotics to treat bacterial infections in pregnant mares, but these treatments face significant clinical hurdles. “Although these treatments can be effective, they do not always eliminate infections, particularly when bacteria become resistant to the medications being used,” Helmy stated. Antibiotics can also disrupt microbial communities and may affect reproductive health.

Bacterial biofilms contribute to persistent infections and make it difficult to achieve effective drug concentrations at the site of infection. “The goal is to find treatments that can control the infection and potentially reduce reliance on conventional antibiotics while limiting the emergence and spread of antimicrobial resistance,” Helmy explained.

Collaboration with Centers of Biomedical Research Excellence

The project, titled “Development of Novel Small-Molecule Therapeutics to Control Pathogens Causing Abortion in Mares,” aims to identify compounds that effectively target harmful bacteria while evaluating their effects on host cells and beneficial microorganisms. Researchers will evaluate promising candidates for activity against antibiotic-resistant bacterial strains, biofilm prevention, and potential toxicity to mammalian cells.

To advance these goals, the project draws on the resources of the Centers of Biomedical Research Excellence (COBRE) for Translational Chemical Biology. Researchers in Helmy’s laboratory will collaborate with COBRE to identify and test compounds, including those found in nature, that can stop harmful bacteria from growing, spreading, or forming biofilms.

Future Therapeutic Outlook for Equine Breeding

The work remains in its early stages, and researchers must thoroughly evaluate the compounds before determining if they can become safe, effective treatments for pregnant mares. Funding for the research was provided in part by a grant from the American Quarter Horse Foundation. Additional support came from the National Institute of General Medical Sciences of the National Institutes of Health under Award Number P20GM130456.

“For the equine industry, even modest improvements in preventing infectious abortions could have meaningful benefits,” Helmy noted. “Protecting a pregnancy means more than saving a potential foal; it can also help preserve a mare’s reproductive health and protect the investments breeders make in future generations of horses.”

Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding any medical condition, diagnosis, or treatment plan.