Eclampsia (Milk Fever)

What is it?

Eclampsia (hypocalcemia, puerperal tetany) is a dangerous drop in blood calcium. It most often happens when puppies are one to four weeks old and the mother is making the most milk, but it can also occur before birth. Causes may include calcium loss to the growing puppies and to milk, an unbalanced diet during pregnancy and nursing, calcium supplements during pregnancy, or a parathyroid problem. Small breeds such as Chihuahuas, Pomeranians, toy poodles, miniature pinschers, and shih tzus are at higher risk, and Merck notes it is most common in dogs under about 45 pounds, especially with a large litter.

What signs should I watch for?

Early signs are subtle: restlessness, panting, and stiff walking that can progress to being unable to walk. Muscle spasms (tetany) can spread through the whole body and lead to seizures. Some dogs have a fever, seem disoriented, restless, or aggressive, pace, rub their face, or have small pupils or a raised third eyelid. If you suspect eclampsia, stop the puppies from nursing and contact your veterinarian immediately.

How is it diagnosed and treated?

Your veterinarian will confirm low calcium with blood tests and give intravenous fluids and calcium. Calcium must be given slowly while the heart is monitored. Some dogs need anti-seizure medication. Follow-up usually includes oral calcium supplements and weaning the puppies as quickly as possible.

Can it be prevented, and what's the outlook?

• With prompt treatment, recovery is usually rapid and complete.
• Feed a high-quality diet made for pregnant and nursing mothers.
• Do not give calcium supplements or dairy during pregnancy unless your veterinarian advises it, because too much calcium can suppress the parathyroid gland and raise the risk.
• For at-risk mothers, puppies may be separated a few times a day so she can eat, and supplemented with milk replacer, moving to puppy food at three to four weeks.