Eclampsia In Dogs And Cats

Eclampsia can occur in dogs (and cats) from just before whelping until four weeks after birth (and, rarely, later).

Eclampsia, also called puerperal* tetany, is defined as low blood calcium levels detected just before or up to 4 weeks after giving birth to puppies and/or during lactation (giving milk, feeding puppies). Eclampsia occurs in cats, but much less often than in dogs. Signs can be terrifying to pet owners, as feeding mothers can exhibit lethargy, trembling, weakness, faint pulse, collapse, seizures and, in untreated cases, death. Hyperthermia (increased body temperature) is a common finding, due to the heat generated by uncontrollable muscle trembling.

The term eclampsia derives from New Latin, originating with the Greek word eklampsis, meaning “a sudden flashing.” Eklampsis comes from eklampien, meaning “to shine forth.” It was coined by Varandaeus in 1619 to describe the sensation experienced by women in pre-eclampsia who saw flashing lights or spots.

A common predisposing factors is inappropriate calcium supplementation during pregnancy. Dosing with calcium tablets or feeding calcium-rich, phosphorous-poor cottage cheese can interfere with the body’s natural means of regulating calcium.

Eclampsia occurs most commonly in small-breed dogs with large litters.

Pregnant bitches experience “letdown,” a vernacular term for milk production, beginning shortly before birthing their pups. Small dogs produce less total volume of milk than a proportionately larger dog. Therefore, when an unusually large number of puppies begin consuming all of the milk she produces, the demand for calcium is quite large. Under normal conditions, the body sends out a hormonal signal to begin moving calcium from bones into the bloodstream and other body fluids. At the same time, the gastrointestinal (GI) tract is signaled to enhance absorption of calcium from food.

When everything works properly, sufficient calcium is delivered for milk production plus what the skeletal muscles, heart muscle and tiny muscles in blood vessels require. However, in the case of a small dam with too many puppies to feed, her tiny body may not be able to mobilize calcium at the rate calcium-rich milk is being consumed by the litter.

Also, if prepartum calcium supplementation has occurred, the body’s normal signal pathways have been told to turn off the mechanisms that mobilize calcium because so much excess calcium is coming in.

Eclampsia is a medical emergency. It requires immediate treatment by a licensed veterinarian. The most involved cases may require intravenous administration of a special form of calcium. Not all calcium formulations can be administered by the IV route. Less critical patients may need treatment by intramuscular or subcutaneous administration of calcium. It is perfectly acceptable to supplement dietary calcium in the following conditions:

  • after delivery for patients who have required treatment for eclampsia while nursing this litter of puppies or kittens.
  • after delivery for dams who have experienced eclampsia while nursing previous litters.
  • in the final week of gestation for mothers who have had eclampsia prior to delivery in previous litters.

Your pet’s doctor will advise you on the form and dosage of calcium to administer.

See you next week, Dr. Randolph.


*from the Latin puerperas, from puer, meaning “child or boy,” and parare, meaning “to bear.”

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