Dog health guide · Postpartum symptoms

Eclampsia (Milk Fever) in Nursing Dogs: Early Warning Signs

Eclampsia can go from mild restlessness to a seizure in a matter of hours. Here are the early signs that are easy to miss, and why catching them early matters so much.

Warning signs graphic representing when a dog symptom needs emergency veterinary care
Amy Shojai
Written by , Certified Animal Behavior Consultant (CABC) · Updated July 11, 2026 • 7 min read
⚡ Quick Answer

Eclampsia is a drop in blood calcium in a nursing mother, usually developing two to four weeks after whelping when milk production is at its peak. The earliest signs, restlessness, panting, and a stiff or uncomfortable gait, are easy to mistake for normal new-mother tiredness. Left unaddressed, it can progress within hours to muscle tremors, fever, and seizures. Any unusual restlessness or stiffness in a nursing mother is worth a same-day call to your veterinarian.

Why nursing causes this

Producing milk for a litter of puppies places a heavy calcium demand on a mother's body, since calcium is a key component of milk. If her body can't mobilize and replace calcium fast enough to keep up with that demand, blood calcium levels drop, a condition called hypocalcemia, which in nursing mothers is commonly referred to as eclampsia or milk fever. It typically develops during peak milk production, usually two to four weeks after whelping, and tends to be more common in small breed mothers and in mothers nursing unusually large litters, since both situations increase the calcium demand relative to the mother's size.

The early signs that get missed

The trouble with eclampsia is that its earliest signs look a lot like ordinary exhaustion in a dog who just went through labor and is now nursing around the clock. Watch for:

None of these signs alone confirms eclampsia, but in a nursing mother within the first few weeks postpartum, this combination is worth a same-day call to your vet rather than a wait-and-see approach.

What happens if it progresses

Without treatment, eclampsia can progress from these subtle early signs to more serious symptoms within hours: muscle tremors, stiffening or spasming muscles, a notably elevated body temperature, disorientation, and eventually seizures. At this stage, it is a genuine medical emergency requiring immediate veterinary treatment, typically intravenous calcium administered under close monitoring. The progression can happen fast enough that a dog who seemed only mildly restless in the morning can be having seizures by evening, which is exactly why early recognition matters so much.

Treatment and prevention

Treatment for confirmed eclampsia involves calcium supplementation, usually given intravenously in an acute episode, with oral calcium and dietary adjustments to follow under veterinary guidance. Because the underlying cause is the calcium demand of nursing, your veterinarian may also discuss options like supplementing the litter with formula to reduce the mother's nursing load if the litter is very large, alongside monitoring her calcium levels going forward. Interestingly, calcium supplementation during pregnancy itself is generally not recommended, since it can sometimes disrupt the body's normal calcium regulation and paradoxically increase eclampsia risk after delivery, so any supplementation plan should be guided by your vet rather than done preventively on your own.

📚 Trusted Resources: For further reading and clinical guidance, we recommend the American Veterinary Medical Association (AVMA) and VCA Animal Hospitals.
What causes eclampsia in nursing dogs?
Eclampsia, also called milk fever or puerperal tetany, happens when a nursing mother's blood calcium drops too low, usually because milk production is drawing calcium out of her system faster than her body can replace it. It most often develops during peak milk production, typically two to four weeks after whelping, and is more common in small breeds and mothers with large litters.
What are the earliest signs of eclampsia in dogs?
The earliest signs are often subtle: restlessness, panting, a stiff or uncomfortable gait, and mild anxiety or clinginess. These early signs are easy to mistake for normal new-mother exhaustion, which is exactly why they get missed. Catching eclampsia at this stage, before tremors or seizures develop, makes treatment much more straightforward.
Is eclampsia in dogs an emergency?
Yes. Eclampsia can progress quickly from mild restlessness to muscle tremors, high fever, and seizures within hours. Any nursing mother showing restlessness, panting, or stiffness that doesn't fit her normal behavior should be seen by a veterinarian the same day, rather than waiting to see if it resolves on its own.