CONDITION
Eclampsia in Dogs
Eclampsia is a condition in which calcium levels in the blood drop rapidly, typically in the first few weeks after whelping when a dog is nursing puppies, and less often in late pregnancy or during whelping. The body's demand for calcium can outpace what is available in circulation, and this imbalance affects how nerves and muscles function. Owners often notice restlessness, panting, or muscle tremors that appear suddenly in a nursing dog. Some dogs become unsteady or disoriented. Over a matter of hours these early signs can give way to stiffness, inability to stand, seizures and a high body temperature, and without calcium replacement the condition can lead to coma and death. How far the calcium has fallen cannot be judged from the signs at home. Small dogs and those nursing large litters are affected most often, though it can occur in any lactating dog. This page explores what the early signals of eclampsia can look like, the mechanism by which calcium depletion affects the body, how the condition is investigated, and the range of approaches used to address it.
Why this matters now
Eclampsia occurs most commonly in lactating dogs, typically within the first four weeks after whelping when milk production is at its peak, though it can also develop in late pregnancy or during whelping. Small breeds with large litters are affected most often, but the condition can develop in any breed, with any litter size and at any stage of lactation. Calcium supplements given during pregnancy are associated with a higher risk of eclampsia rather than a lower one, because extra calcium at that stage dampens the parathyroid response the body relies on once milk production begins.
The onset tends to be sudden, often appearing over the course of hours rather than days. Restlessness, panting and mild tremor are typically the first stage of the same process rather than a separate, milder problem, and over a matter of hours they can give way to muscle rigidity, inability to stand, generalised seizures and a rising body temperature driven by constant muscle activity. Without calcium replacement the condition can progress to coma and death. How far the calcium has fallen cannot be judged from the signs at home, and some dogs show little warning before rigidity or seizures appear. Signs can also return after treatment if the litter continues to feed without changes.
Signals & patterns
Early signals
Restlessness and pacing
A nursing dog may appear unable to settle, moving between resting spots or circling without clear purpose. This behaviour often emerges abruptly and persists despite attempts to comfort.
Panting without exertion
Rapid, shallow breathing may begin even in a cool environment or after minimal activity. The panting can seem disproportionate to the dog's recent movement or the ambient temperature.
Mild muscle tremors
Fine, rhythmic shaking may be visible in the limbs or face, sometimes described as a quivering or twitching. These tremors often worsen with handling or excitement. In a nursing or heavily pregnant dog, even fine tremor can reflect falling blood calcium and can be the start of the more severe picture described below.
Reduced interest in puppies
A dog who previously nursed attentively may begin to avoid the litter or seem distracted during feeding. This shift in maternal behaviour can be subtle at first.
Later signals
Stiff or unsteady gait
Movement may become rigid or clumsy, with the dog appearing to walk on stiff legs or stumble. Some dogs hold their limbs in an extended or awkward posture.
Disorientation or confusion
The dog may seem unaware of her surroundings, fail to recognise familiar people, or stand motionless staring into space. Responsiveness to voice or touch may diminish.
Generalised muscle spasms
Larger, involuntary contractions can affect the whole body, sometimes with the dog lying on her side and paddling or appearing unable to stand. These episodes may come in waves.
Seizures
Some dogs have generalised seizures, losing awareness and falling to one side with rigid or paddling limbs. In a nursing dog, seizures can arise from low calcium, and low blood glucose can be present at the same time; neither can be measured at home.
High body temperature
Constant tremor and rigidity generate heat, and body temperature can rise well above normal. The dog may feel hot to the touch, pant heavily and drool. A rising temperature tends to accompany the more severe form of the condition.
Click to read about the biological mechanisms
How this is usually investigated
The investigation typically begins with a clinical history that focuses on lactation status, litter size, and the timing and nature of the signs. Physical examination often reveals tremors, muscle rigidity, elevated heart rate, or altered responsiveness. Blood testing is used to measure calcium levels directly, and this result usually clarifies the picture when the clinical context fits.
Clinical history and observation
Blood biochemistry
Blood glucose measurement
Physical examination findings
Options & trade-offs
Management of eclampsia usually involves restoring blood calcium levels and reducing the immediate demand for calcium through milk production. Calcium replacement is the core of treatment whatever the severity of the signs, because tremor can move on to rigidity, seizures and a high temperature within hours and the calcium level cannot be judged from the signs at home. Stopping the puppies from suckling, weaning and supportive care are used alongside calcium replacement rather than in place of it. What varies between dogs is how the litter is fed afterwards and how long oral calcium is continued.
Intravenous calcium supplementation
Calcium is administered slowly through a vein, often as calcium gluconate, whilst the heart rate is monitored. The effect can be rapid, with tremors and rigidity subsiding within minutes to hours. The infusion is given carefully because calcium delivered too quickly can disturb heart rhythm.
Trade-offs: This approach requires access to a clinical setting and monitoring equipment. The effect is temporary if the underlying drain on calcium continues, so further supplementation or adjustments to lactation may be needed. Some dogs experience a recurrence if the litter continues to nurse without modification.
Oral calcium supplementation
Once the acute phase has been managed, calcium can be given by mouth to maintain blood levels whilst lactation continues or until the puppies are weaned. The dose and frequency are adjusted based on the dog's size, the number of puppies, and any repeat blood tests.
Trade-offs: Absorption from the gut is slower and less predictable than intravenous delivery, so this approach is typically used for maintenance rather than immediate correction. Over-supplementation can lead to elevated calcium in the long term, which carries its own risks, so monitoring is helpful.
Stopping suckling or weaning, alongside calcium replacement
Keeping the puppies from suckling and feeding them a milk replacer reduces the demand for calcium while treatment takes effect. This is done together with calcium replacement, not as a substitute for it, because removing the puppies does not raise a blood calcium level that has already fallen. Where signs return, or the puppies are old enough, the litter is often weaned fully, and puppies can usually move on to puppy food from about three to four weeks of age.
Trade-offs: Hand-rearing is time-intensive and requires commitment, particularly if the litter is large or very young. Abrupt weaning can cause engorgement of the mammary glands, which may be uncomfortable and can increase the risk of mastitis. Weaning, whether sudden or gradual, does not by itself correct a calcium level that has already fallen, so it does not take the place of calcium replacement during an episode.
Supportive care during recovery
A quiet, dimly lit environment can reduce sensory stimulation that may worsen muscle excitability or agitation. Temperature is monitored because some dogs develop hyperthermia secondary to muscle activity. Fluid therapy may be given if the dog is dehydrated or if intravenous access is already in place for calcium administration.
Trade-offs: Supportive measures do not address the calcium imbalance directly, so they are used alongside calcium replacement rather than as standalone treatment. They form part of care in a clinical setting, where temperature, heart rate and calcium can be measured, and a dog whose signs appear mild can still move on to rigidity and seizures within hours.
Common misconceptions
"Calcium supplementation during pregnancy prevents eclampsia."
Giving high doses of calcium before whelping can suppress the parathyroid glands, which are responsible for mobilising calcium from bone when lactation begins. This suppression may leave the dog less able to respond to the sudden demand for calcium after birth. Calcium given during lactation, once signs appear or as maintenance, is a different scenario.
"Eclampsia only happens in dogs with poor nutrition or inadequate diets."
Well-fed dogs with balanced diets can still develop eclampsia if the rate of calcium loss into milk exceeds the body's capacity to mobilise reserves. Smaller breeds and those with large litters face disproportionate metabolic demands, regardless of what they were fed before or during pregnancy. Nutrition influences overall health, but it does not eliminate the risk.
"Once a dog has had eclampsia, she will always have it with future litters."
Eclampsia is likely to recur in later litters, although not every dog that has had it once will have it again. The risk can be reduced by giving the puppies supplementary feeds from early in lactation and by weaning them early, and large litters place the greatest demand on the mother's calcium.
Related conditions
Addisons Disease in Dogs
Addison's disease can present with episodic weakness and collapse in a way that may superficially resemble the acute onset seen in eclampsia, though the underlying mechanism—insufficient adrenal hormones rather than calcium depletion—is entirely different. The context of recent whelping and lactation typically points toward eclampsia.
Epilepsy in Dogs
Epilepsy in dogs can be considered in the differential diagnosis when a dog presents with tremors or seizure-like activity, as eclampsia itself can cause generalised seizures that look much the same. The timing in relation to lactation and measurement of blood calcium help clarify the underlying cause.
Mastitis
Mastitis is inflammation of the mammary glands in a nursing dog and can also cause restlessness, a raised temperature and reluctance to feed the puppies. Abrupt weaning, sometimes used to reduce calcium demand after eclampsia, can lead to engorgement and make mastitis more likely.
In a nursing or heavily pregnant dog, restlessness, panting and tremor can be the first stage of eclampsia, and the picture can move on to rigidity, seizures and a high temperature within hours. Blood calcium and glucose cannot be assessed at home, and oral calcium acts more slowly and less predictably than calcium given into a vein, which is why it tends to be used for maintenance rather than to correct a falling level. Once an episode has been treated, the conversation often turns to the rest of the current lactation, including supplementary feeding or weaning of the puppies, and to the risk in future litters. Calcium supplements during pregnancy may increase that risk rather than reduce it.
Last reviewed: 13 September 2026 · Dr Alastair Greenway MRCVS