Managing Ruminant Metabolic Disorders and Milk Fever

Posted on Jun 21, 2026 in Medicine

Dietary Anions for Milk Fever Prevention

Adding anions such as chloride (Cl^–) or sulfate (SO₄^2-) to the diet of dairy cows during the last 10–21 days of pregnancy is a highly effective prevention method for milk fever (parturient paresis). This practice induces a mild metabolic acidosis, which lowers blood pH and enhances tissue responsiveness to parathyroid hormone (PTH). Consequently, both bone resorption and intestinal absorption of calcium are increased.

Commonly used salts include CaCl₂, NH₄Cl, and MgSO₄. Because these salts have poor palatability, they are typically mixed with molasses or corn silage. While sulfates are more palatable than chlorides, they are generally less effective at inducing the necessary metabolic shift.

Pregnancy Toxemia in Does: Diagnosis and Care

Suspected Diagnosis: Pregnancy Toxemia (Ovine Ketosis)

A late-pregnant doe presenting with anorexia for 24 hours, drowsiness, a distended abdomen (suggesting multiple fetuses), subnormal temperature, faint heartbeats, and foamy salivation is likely suffering from pregnancy toxemia. These clinical signs are characteristic of severe ketoacidosis in goats.

Medical Intervention

• Glucose Therapy: Administer 200–300 mL of 25% glucose IV twice daily.
• Oral Glucogenic Precursors: Provide 100–200 mL of propylene glycol or glycerin orally for 3 days.
• Acidosis Correction: Use sodium bicarbonate IV to correct ketoacidosis.
• Calcium Support: Administer 50–100 mL of calcium IV if hypocalcemia is suspected.
• Induction of Parturition: Use dexamethasone (20 mg IV) and PGF_2α (10 mg IM) to deliver kids within 24–72 hours.
• Prognosis: If the doe is recumbent and comatose, the prognosis is considered hopeless.

Hypokalemia in Alert Downer Cows

Diagnosis: Severe Hypokalemia

An “alert downer” cow that is unable to support the weight of her head (resting it on the ground or chest) following a history of anorexia and dextrose injection is a classic case of hypokalemia. Dextrose triggers insulin release, which drives potassium (K) into the cells, exacerbating low blood potassium levels.

Medical Intervention

1. Oral Potassium Chloride (KCl): This is the treatment of choice.
   • Mild cases: 60 g KCl twice at 12-hour intervals.
   • Severe cases (Serum K < 2.5 mEq/L): 120 g KCl, repeated after 12 hours (total 240 g/24h).
2. Physiotherapy: Regularly roll the cow, provide soft bedding, and perform limb massages.
3. Monitoring: Avoid IV potassium if possible, as it is dangerous and can cause fatal cardiac arrhythmias.

Bovine Ketosis: Risk Factors and Lab Findings

Causes and Risk Factors

• Starvation and negative energy balance in early lactation.
• High milk yield (lactation stress).
• High body condition score (>3.75) or overconditioning at calving.
• Sudden increases in concentrate feed at calving.
• Overfeeding during the dry period.
• Secondary factors: Displaced abomasum (DA), metritis, mastitis, or reticulitis.

Laboratory Examination Results

• Hyperketonemia: Elevated BHB and acetoacetate.
• Ketonuria and Ketolactia: Positive ketone levels in urine and milk.
• Hypoglycemia: Low blood glucose levels.
• Elevated NEFA: High free fatty acids indicating intense fat mobilization.
• Note: CPK and AST levels remain normal as they indicate muscle damage, not ketosis.

Clinical Signs of Lactation and Calf Tetany

Lactation Tetany in Cattle

This condition is characterized by hyperexcitability triggered by touch or sound. Clinical signs include tetany (stiff limbs, paddling convulsions), opisthotonos, nystagmus, and frothy salivation. Heart sounds are often loud and irregular. Without treatment, death from respiratory failure can occur within 30–60 minutes.

Differential Diagnosis for Calf Tetany

Calf tetany must be differentiated from the following conditions:

• Hypocalcemia and hypokalemia.
• Tetanus and acute lead poisoning.
• Hypophosphatemia (associated with anemia).
• Polioencephalomalacia and meningitis.
• Enterotoxemia.

Physiotherapy and Care for Downer Cows

Effective nursing care is vital for the recovery of a downer cow:

• Rolling: Move the cow from side to side every 3 hours to prevent hypostatic pneumonia, bloat, and decubitus ulcers.
• Positioning: Maintain sternal recumbency using straw bales for support.
• Bedding: Use soft surfaces like sand or deep straw.
• Massage: Massage limbs and bony prominences three times daily to prevent ischemic necrosis.
• Assistance: Use a sling, if available, to help the animal stand.

Hypocalcemia and Eclampsia in Mares

Hypocalcemia in mares, often called eclampsia, typically occurs during lactation, frequently following transport or heavy exercise. Clinical signs include:

• Restlessness, anxiety, and profuse sweating.
• Muscle tremors in the face, flanks, and shoulders.
• Ataxia, stiff gait, and tachycardia (weak, rapid pulse).
• Prolapse of the third eyelid.
• In severe cases, recumbency and convulsions leading to respiratory failure.

Managing Grass Tetany in Bulls

Immediate handling is required for a bull showing signs of grass tetany:

1. Tranquilization: Use xylazine or chlorpromazine to control convulsions.
2. IV Therapy: Administer 500 mL of a Ca-Mg preparation slowly. Never give magnesium alone IV, as it causes cardiac arrest.
3. Subcutaneous Magnesium: Follow with 200–300 mL of 20% magnesium sulfate divided into multiple sites.
4. Oral Follow-up: Provide 60–120 g of magnesium oxide daily for several days.
5. Nursing: Keep the bull in a quiet, stress-free environment with deep bedding.

Calcium Cyclers and Milk Fever in Ewes

Management of Calcium Cyclers

“Calcium cyclers” are cows that relapse into hypocalcemia 24–72 hours after successful treatment. This is often caused by high calcium intake during the dry period (which suppresses PTH) or complete udder evacuation. Management involves repeating calcium therapy (IV and SC) combined with Vitamin D, and practicing incomplete milking for 48 hours post-calving.

Milk Fever in Ewes

Treatment requires 50–150 mL of 25% calcium borogluconate administered very slowly via IV. Because calcium is cardiotoxic, the heart must be monitored; if arrhythmias occur, stop the injection immediately. Adequate calcium intake in late gestation and avoiding high-potassium pastures can help prevent the condition.

Treatment Strategies for Creeper Cows

Creeper cows require a multi-faceted medical approach:

• Phosphorus: 60 g sodium acid phosphate IV, followed by SC and oral doses for 3 days.
• Potassium: Oral KCl (60–120 g) twice daily if hypokalemic.
• Anti-inflammatories: NSAIDs or corticosteroids to reduce nerve and muscle inflammation.
• Vitamins: Vitamin B complex, Vitamin E + Se, and AD₃E.
• Prognosis: Recovery is likely if treated within 12 hours; after 24 hours, muscle changes may become irreversible.

Causes and Risk Factors of Hypokalemia

Additional Risk Factors: High-concentrate diets (leading to rumen acidosis and anorexia), diarrhea, and prolonged recumbency in downer cows.