Parturient Paresis in Sheep and Goats

Core Definition & Characteristics:

Nature of Disease: A metabolic disturbance defined by acute-onset hypocalcemia.
Physiological Impact: Rapid progression from hyperexcitability to weakness, ataxia, recumbency, coma, and death if untreated.
Timing:
- Can occur from 6 weeks before to 10 weeks after parturition.
- Prepartum (Most common): Due to high calcium demands for fetal skeletal mineralization, especially with multiple fetuses.
- Postpartum: Primarily affects high-producing dairy goats due to calcium loss in milk.

Etiology (Causes) & Risk Factors:

The Imbalance: Decreased calcium intake paired with increased requirements.
Metabolic Lag: The body requires 24–72 hours to activate mechanisms to mobilize stored bone calcium; this lag can be fatal during sudden demand.
Dietary Risks:
- Low-calcium forages (cereal hays, corn silage, poor-quality pasture).
- High-phosphorus grains (creating an inverse Ca:P ratio).
- Vitamin D deficiency (common in housed animals during winter).
Triggers: Sudden feed changes, abrupt weather changes, or fasting (e.g., during shearing or transportation).

Clinical Findings:

General Signs: Stiff gait, ataxia, muscle tremors, and tachycardia with quieter-than-normal heart sounds.
Gastrointestinal: Salivation, constipation, and depressed rumen motility leading to bloat.
Species Differences:
- Ewes: Often found in a "sternal froglike position" with hindlegs extended backward.
- Goats: Muscle tremors are significantly more common than in ewes.

Diagnosis:

Field Diagnosis: Based on history (late gestation/early lactation), clinical signs, and a rapid response to calcium treatment.
Biochemical Threshold: Confirmed by total serum calcium < 1.2 mmol/L (5.0 mg/dL).
Differential Diagnosis: Pregnancy toxemia is the main differential and frequently occurs concurrently.

Treatment Protocols:

Immediate Action: Administration of IV or SC calcium borogluconate (23% solution).
IV Administration:
- Dose: 50–100 mL.
- Protocol: Must be given slowly (5–7 minutes) while monitoring the heart for arrhythmias.
SC Administration:
- Dose: 30–60 mL.
- Precautions: Divide the volume into multiple sites; do not use solutions containing dextrose subcutaneously as they irritate tissue.

Prevention Strategies:

Nutritional Management:
- Ensure a Ca:P ratio > 1.5:1 throughout gestation.
- Provide adequate Vitamin D and meet NRC dietary requirements.
Management Practices: Avoid sudden dietary changes and reduce stressors during the critical final 6 weeks of gestation.

Parturient Paresis in Sheep and Goats

Core Definition & Characteristics:

Nature of Disease: A metabolic disturbance defined by acute-onset hypocalcemia.

Physiological Impact: Rapid progression from hyperexcitability to weakness, ataxia, recumbency, coma, and death if untreated.

Timing:

Can occur from 6 weeks before to 10 weeks after parturition.

Prepartum (Most common): Due to high calcium demands for fetal skeletal mineralization, especially with multiple fetuses.

Postpartum: Primarily affects high-producing dairy goats due to calcium loss in milk.

Etiology (Causes) & Risk Factors:

The Imbalance: Decreased calcium intake paired with increased requirements.

Metabolic Lag: The body requires 24–72 hours to activate mechanisms to mobilize stored bone calcium; this lag can be fatal during sudden demand.

Dietary Risks:

Low-calcium forages (cereal hays, corn silage, poor-quality pasture).

High-phosphorus grains (creating an inverse Ca:P ratio).

Vitamin D deficiency (common in housed animals during winter).

Triggers: Sudden feed changes, abrupt weather changes, or fasting (e.g., during shearing or transportation).

Clinical Findings:

General Signs: Stiff gait, ataxia, muscle tremors, and tachycardia with quieter-than-normal heart sounds.

Gastrointestinal: Salivation, constipation, and depressed rumen motility leading to bloat.

Species Differences:

Ewes: Often found in a "sternal froglike position" with hindlegs extended backward.

Goats: Muscle tremors are significantly more common than in ewes.

Diagnosis:

Field Diagnosis: Based on history (late gestation/early lactation), clinical signs, and a rapid response to calcium treatment.

Biochemical Threshold: Confirmed by total serum calcium < 1.2 mmol/L (5.0 mg/dL).

Differential Diagnosis: Pregnancy toxemia is the main differential and frequently occurs concurrently.

Treatment Protocols:

Immediate Action: Administration of IV or SC calcium borogluconate (23% solution).

IV Administration:

Dose: 50–100 mL.

Protocol: Must be given slowly (5–7 minutes) while monitoring the heart for arrhythmias.

SC Administration:

Dose: 30–60 mL.

Precautions: Divide the volume into multiple sites; do not use solutions containing dextrose subcutaneously as they irritate tissue.

Prevention Strategies:

Nutritional Management:

Ensure a Ca:P ratio > 1.5:1 throughout gestation.

Provide adequate Vitamin D and meet NRC dietary requirements.

Management Practices: Avoid sudden dietary changes and reduce stressors during the critical final 6 weeks of gestation.