Pregnancy Toxemia in Sheep and Goats

Definition: The most common metabolic disorder of pregnant small ruminants.

⏳Timing: Occurs during the final stage of gestation (late pregnancy).

💡Mechanism: Result of inappropriate metabolism of carbohydrates and fats, leading to hypoglycemic encephalopathy.

📋Key Indicator: Characterized by increased concentrations of beta-hydroxybutyrate (BHB) in the blood and urine.

Etiology and Pathogenesis:

The Energy Gap:
- Metabolizable energy requirements rise dramatically in the last 4 weeks of gestation (23% for single, 36% for twins, and 42% for triplets).
- Decreased rumen capacity occurs as the growing fetuses take up more space.
- Each fetus requires 30–40 g of glucose per day, which is prioritized over the dam's needs.
Physiological Response:
- The liver increases gluconeogenesis to meet demand.
- Massive fat mobilization occurs; if this overwhelms the liver, it leads to hepatic lipidosis (fatty liver).
Risk Factors:
- Body Condition Score (BCS): Animals with a BCS ≤2/5 (thin) or ≥4/5 (overconditioned) are at highest risk.
- Multiple Fetuses: Carrying twins or triplets significantly increases susceptibility.
- Stressors: Adverse weather, transport, shearing, or handling can acutely curtail feed intake and trigger clinical signs.
- Concomitant Disease: Lameness, dental disease, footrot, or pneumonia.
Variants:
- Primary: Caused by thin condition and inadequate nutrition.
- Estate Ketosis: Caused by overconditioning (obesity).
- Secondary: Triggered by other underlying diseases.

Clinical Findings:

Onset: Usually 1–3 weeks before parturition.
Early Signs: Selective anorexia (refusing grain), listlessness, and increased time spent recumbent.
Neurologic Progression (2–4 days):
- Aimless walking, muscle twitching, tremors, teeth grinding, and blindness.
- Progresses to ataxia and sternal recumbency.
Terminal Stage: Coma and death; if the fetus dies, septicemia develops in the dam.
Postmortem Lesions: Fatty liver, enlarged adrenal glands, and decomposing fetuses.

Diagnosis:

Definitive Diagnosis: Required via laboratory tests to confirm clinical suspicion.
Key Laboratory Markers:
- Serum BHB: Normal is <0.8 mmol/L; subclinical ketosis is ≥0.8 mmol/L; clinical disease is >3 mmol/L.
- Hypoglycemia: Often <2 mmol/L, though blood glucose may rebound to normal or high after fetal death.
- Aqueous Humor BHB: >2.5 mmol/L (postmortem).
- CSF BHB: >0.5 mmol/L (postmortem); CSF glucose remains low even if serum glucose rebounds.
Differential Diagnosis: Must be distinguished from hypocalcemia, hypomagnesemia, polioencephalomalacia, enterotoxemia, and listeriosis.

Treatment Strategies:

Early Stages (Ambulatory):
- Propylene Glycol: 60 mL orally every 12 hours for 3 days.
- Supportive Supplements: Calcium lactate (12.5 g) and potassium chloride (7.5 g).
- Insulin: Protamine zinc insulin (0.4 U/kg SC).
Advanced Stages (Poor Prognosis):
- Fatality rate is often >40% in clinical cases.
- IV Dextrose: 60–100 mL of 50% solution, followed by a 5% dextrose drip.
- Anti-inflammatories: Flunixin meglumine (2.5 mg/kg) to improve survival.
Managing the Pregnancy:
- Induction: Dexamethasone (20 mg IV/IM) to induce parturition or abortion.
- C-Section: Considered if fetuses are alive and within 3 days of the due date.
- Euthanasia: Warranted if the animal is already comatose.

Prevention and Management:

Nutritional Planning:
- Grain Supplementation: Required in the last 6 weeks of gestation for multiple-bearing females.
- BCS Target: Ewes/does should not enter the final 6 weeks with a BCS <2.5/5.
Flock Management:
- Sorting: Group animals based on condition and fetal numbers (determined by ultrasound).
- Monitoring: Screen the flock by testing serum BHB in 10–20 animals (normal mean should be 0–0.7 mmol/L).
- Anthelmintics: Effective parasite control contributes to prevention.

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Pregnancy Toxemia in Sheep and Goats

Definition: The most common metabolic disorder of pregnant small ruminants.

⏳Timing: Occurs during the final stage of gestation (late pregnancy).

💡Mechanism: Result of inappropriate metabolism of carbohydrates and fats, leading to hypoglycemic encephalopathy.

📋Key Indicator: Characterized by increased concentrations of beta-hydroxybutyrate (BHB) in the blood and urine.

Etiology and Pathogenesis:

The Energy Gap:

Metabolizable energy requirements rise dramatically in the last 4 weeks of gestation (23% for single, 36% for twins, and 42% for triplets).

Decreased rumen capacity occurs as the growing fetuses take up more space.

Each fetus requires 30–40 g of glucose per day, which is prioritized over the dam's needs.

Physiological Response:

The liver increases gluconeogenesis to meet demand.

Massive fat mobilization occurs; if this overwhelms the liver, it leads to hepatic lipidosis (fatty liver).

Risk Factors:

Body Condition Score (BCS): Animals with a BCS ≤2/5 (thin) or ≥4/5 (overconditioned) are at highest risk.

Multiple Fetuses: Carrying twins or triplets significantly increases susceptibility.

Stressors: Adverse weather, transport, shearing, or handling can acutely curtail feed intake and trigger clinical signs.

Concomitant Disease: Lameness, dental disease, footrot, or pneumonia.

Variants:

Primary: Caused by thin condition and inadequate nutrition.

Estate Ketosis: Caused by overconditioning (obesity).

Secondary: Triggered by other underlying diseases.

Clinical Findings:

Onset: Usually 1–3 weeks before parturition.

Early Signs: Selective anorexia (refusing grain), listlessness, and increased time spent recumbent.

Neurologic Progression (2–4 days):

Aimless walking, muscle twitching, tremors, teeth grinding, and blindness.

Progresses to ataxia and sternal recumbency.

Terminal Stage: Coma and death; if the fetus dies, septicemia develops in the dam.

Postmortem Lesions: Fatty liver, enlarged adrenal glands, and decomposing fetuses.

Diagnosis:

Definitive Diagnosis: Required via laboratory tests to confirm clinical suspicion.

Key Laboratory Markers:

Serum BHB: Normal is <0.8 mmol/L; subclinical ketosis is ≥0.8 mmol/L; clinical disease is >3 mmol/L.

Hypoglycemia: Often <2 mmol/L, though blood glucose may rebound to normal or high after fetal death.

Aqueous Humor BHB: >2.5 mmol/L (postmortem).

CSF BHB: >0.5 mmol/L (postmortem); CSF glucose remains low even if serum glucose rebounds.

Differential Diagnosis: Must be distinguished from hypocalcemia, hypomagnesemia, polioencephalomalacia, enterotoxemia, and listeriosis.

Treatment Strategies:

Early Stages (Ambulatory):

Propylene Glycol: 60 mL orally every 12 hours for 3 days.

Supportive Supplements: Calcium lactate (12.5 g) and potassium chloride (7.5 g).

Insulin: Protamine zinc insulin (0.4 U/kg SC).

Advanced Stages (Poor Prognosis):

Fatality rate is often >40% in clinical cases.

IV Dextrose: 60–100 mL of 50% solution, followed by a 5% dextrose drip.

Anti-inflammatories: Flunixin meglumine (2.5 mg/kg) to improve survival.

Managing the Pregnancy:

Induction: Dexamethasone (20 mg IV/IM) to induce parturition or abortion.

C-Section: Considered if fetuses are alive and within 3 days of the due date.

Euthanasia: Warranted if the animal is already comatose.

Prevention and Management:

Nutritional Planning:

Grain Supplementation: Required in the last 6 weeks of gestation for multiple-bearing females.

BCS Target: Ewes/does should not enter the final 6 weeks with a BCS <2.5/5.

Flock Management:

Sorting: Group animals based on condition and fetal numbers (determined by ultrasound).

Monitoring: Screen the flock by testing serum BHB in 10–20 animals (normal mean should be 0–0.7 mmol/L).

Anthelmintics: Effective parasite control contributes to prevention.