Factors Affecting Survival and Future Foaling Rates in Thoroughbred Mares with Hydrops

Area of Science:

• Veterinary Medicine
• Reproductive Biology
• Equine Health

Background:

• Hydrops, characterized by abnormal fluid accumulation, can affect broodmares.
• Limited evidence exists regarding the long-term prognosis for survival and fertility in affected mares.

Purpose of the Study:

• To describe the prognosis for survival and fertility in mares diagnosed with hydrops at a referral hospital.
• To evaluate the impact of management strategies on mare outcomes.

Main Methods:

• A case series review of medical records for 30 mares diagnosed with hydrops between 2009 and 2019.
• Data collection included history, clinical findings, treatments, survival rates, and future foaling rates.

Main Results:

• Ninety percent of mares survived hydrops, with higher survival rates for hydrallantois (94.7%) than hydramnios (75%).
• Ninety-five percent of surviving mares successfully foaled in the future, with 75% foaling the subsequent year.
• Mares managed with transcervical gradual fluid drainage showed a 100% survival rate compared to 78.6% without this intervention.

Conclusions:

• The prognosis for survival and future fertility in broodmares following hydrops is generally good.
• Appropriate and timely diagnosis and treatment, particularly gradual fluid drainage, are crucial for improving mare survival and reproductive success.
• Complications like hypovolemic shock and hemorrhage significantly impact survival and future breeding potential.