Retrospective Evaluation of Dystocia in Miniature Equids: 78 Cases (2002-2023).

Objective Summary

• This study analyzed 78 instances of dystocia in miniature equids over a 21-year period to describe patient characteristics, correction methods, and outcomes for both mares and foals.

Introduction and Purpose

• Dystocia, or difficult birth, is a critical condition affecting equids, with specific challenges in miniature breeds.
• The study aims to provide a comprehensive retrospective evaluation of dystocia cases in miniature equids, focusing on:
• Patient characteristics (e.g., age, breed)
• Laboratory data related to dystocia
• Fetal orientation causing dystocia
• Methods used to correct the dystocia
• Survival rates of mares and foals
• Complications associated with dystocia and treatment

Methods

• Retrospective data collection from January 2002 to June 2023.
• Data were obtained from an equine referral hospital and field service.
• Seventy miniature equids were included, covering 78 separate dystocia events.
• Variables recorded included:
• Signalment (e.g., breed, age)
• Clinicopathologic data
• Fetal presentation and orientation
• Correction method used during delivery
• Survival outcome to hospital discharge
• Postpartum complications

Results

• Survival Rates:
• Mares had a high survival rate of 94% (73 out of 78 cases survived).
• Foal survival rate was markedly lower at 17% (13 out of 78 cases survived).
• Causes of Dystocia:
• Abnormal limb presentation: 27% of cases (21/78)
• Neck flexion: 23% of cases (18/78)
• Caudal presentation with bilateral hip flexion: 17% of cases (13/78)
• Correction Methods:
• Controlled vaginal delivery (CVD): 45% (35/78)
• Assisted vaginal delivery (AVD): 35% (27/78)
• Cesarean delivery: 17% (13/78)
• Fetotomy (surgical fetal reduction): 4% (3/78)
• Complications Observed:
• Retained fetal membranes: 19% (15/78)
• Metritis (uterine infection): 8% (6/78)
• Obturator nerve paralysis (nerve damage causing locomotion issues): 5% (4/78)
• Hyperlipidemia (excess fat in blood, secondary complication): 5% (4/78)

Discussion and Conclusions

• Miniature equid mares generally have a good prognosis for survival following dystocia, with a 94% survival rate.
• Foal survival remains a major concern, with a relatively low 17% survival rate despite treatment interventions.
• The predominant causes of dystocia relate to fetal positioning and abnormal presentations, which can often be corrected with vaginal delivery techniques.
• Controlled and assisted vaginal deliveries are effective in most cases, reducing the need for cesarean or fetotomy approaches.
• Complications such as retained membranes, metritis, and nerve paralysis, although not extremely frequent, require vigilance during postpartum care.
• The study emphasizes the need for ongoing research and clinical training to improve foal survival rates and refine dystocia management protocols in miniature equids.