Eclampsia in Bitches

Eclampsia in bitches also known as puerperal tetany, milk fever or hypocalcemia in bitches (female dogs).

Eclampsia is an acute life threatening condition caused by extreme hypocalcemia in lactating bitches. Common in small breed dogs having more litter size. It occurs mostly at 2-3 weeks of lactation, when milk production is at peak.

Etiology

• Hypocalcemia develops as the foetuses mineralize and to an even greater extent when the bitch lactates.
• During lactation is a huge drain of calcium form the body calcium stores. Bitches cannot take in enough calcium through the gastrointestinal tract to support milk production and so must draw calcium stores from the bone through the action of parathyroid hormone. Inadequate calcium in the extracellular compartment and subsequent decrease in membrane – bound calcium leads to spontaneous and repeated depolarization of muscle or tetany.
• Excess calcium supplementation during pregnancy may predispose bitches to hypocalcemia through down – regulation of parathyroid hormone.

Clinical Signs

• During early stage bitch will be restlessness, muscle weakness or tremors, facial pruritus, and neglect of the pups.
• As the condition advances, tachycardia or bradycardia, and dilation of the pupils may be seen.
• End stage eclampsia is characterized by convulsions and subsequent hyperthermia.

Diagnosis

• Decreased total blood calcium (<7 mg/dl) or significantly decreased ionized calcium (<0.8 mmol/l) is diagnostic for hypocalcemia.
• Hypomagnesemia and hyperkalemia may also be present.

Differential Diagnosis

• Epilepsy and other neurological diseases.
• A history of recent whelping will aid in the diagnosis of eclampsia.

Treatment

• Hyperthermic animals (>105 F) should be cooled slowly.
• Seizures controlled by administration of diazepam IV or other sedative or anaesthetic agents.
• Hypocalcemia is treated with 10% calcium gluconate @ 0.22 to 0.44 ml/kg or a bolus of 5 to 10 ml IV. The heart should be monitored while calcium is administered intravenously and therapy stopped, if any abnormality of heart rate or rhythm is noted.
• After initial clinical signs have resolved, oral calcium gluconate or calcium carbonate can be given @ 1 to 3 g along with vitamin D @ 10,000 to 25,000 IU. Oral therapy should continue until pups are weaned.
• Recurrence in the same lactation is not uncommon; if clinical eclampsia recurs in a given lactation, pups should be removed and hand-fed.