Eclampsia

Author: Dr. med. vet. Gisa Löwe | Last modified: 05.02.2026
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Fig.: Mother cat caring for her puppy

You might also be interested in: Milk fever (eclampsia) in dogs and cats

Eclampsia
Eclampsia is an acute, life-threatening undersupply of ionized calcium, usually in lactating dogs shortly after birth. Typical are restlessness, muscle tremors, seizures, fever, and stiff gait. Without rapid therapy, it can lead to severe seizures and circulatory problems.

Eclampsia refers to seizures that can occur in dogs before, during, and after birth. However, most often lactating dogs are affected in the period from the 1st to the 4th week after birth. If puppies continue to suck very intensively beyond this, eclampsia can also occur later.
Eclampsia occurs more often in dogs of small breeds such as Terriers, Miniature Schnauzers, Dachshunds or Pugs than in large dog breeds. Young dogs are more likely to get sick than older dogs. In cats, the disease is rarer, but follows a similar pathomechanism. Eclampsia is an absolute veterinary emergency that can be fatal without immediate treatment.

Causes

The main cause of eclampsia is an acute calcium deficiency in the blood, which can be caused by various factors. During lactation, the calcium requirement increases dramatically as large amounts of this mineral are needed for milk production. In a lactating dog, the daily calcium requirement can increase four to six times the normal requirement. This increased demand cannot be met solely by food intake, but also requires efficient mobilization of calcium from the bones, which is regulated by parathyroid hormone.

Several predisposing factors can lead to eclampsia:

  1. Inadequate calcium intake through food during pregnancy and lactation
  2. Disturbed hormonal regulation of calcium balance, especially by parathyroid hormone, calcitonin, and vitamin D
  3. Large litters, which mean an increased calcium requirement for milk production
  4. Genetic predisposition in certain breeds
  5. Paradoxically, excessive supplementation of calcium during pregnancy can also lead to problems, as it can impair the body’s own regulatory mechanisms

The pathophysiology is complex: with a sudden increased calcium requirement, the body cannot mobilize calcium from the bones quickly enough, which leads to a critical drop in serum calcium. Since calcium is necessary for neuromuscular excitation transmission, this deficiency results in the characteristic clinical symptoms.

Symptoms

Milk fever (eclampsia) in dogs and cats

Typical Symptoms:

  • Restlessness, panting, muscle tremors, stiff gait
  • Nervousness, fever possible, tendency to seizures
  • Typical: lactating dog/cat, often 1st–3rd week after birth (post partum).

Alarm signs:

  • Seizures, tetany, hyperthermia, impaired consciousness
  • Tachycardia, severe stiffness, recumbent
  • Rapid deterioration within minutes–hours

Escalation/course:

  • Early signs (restlessness/panting) can lead to seizures within 1–2 hours.
  • Recurrence after initial stabilization possible if lactation continues
  • Any increase in neurological symptoms → emergency treatment

The clinical signs of eclampsia typically develop rapidly and can be dramatic. Initially, affected animals show subtle behavioral changes that can quickly progress to severe neurological and muscular symptoms. The course can be divided into several stages:

In the initial stage, the animals show restlessness, nervousness, increased panting, drooling, and an increased body temperature (often above 40 °C). The mothers appear anxious and may neglect or reject their puppies. An increased sensitivity to external stimuli is often observed.

As the disease progresses, clear neuromuscular symptoms appear: muscle tremors, starting on the head and face, that spread to the entire body; stiff, uncoordinated gait; muscle stiffness and tetany. Characteristic is the so-called “sawhorse stance”, in which the legs are stiffly extended and the head is bent backwards.

In the advanced stage, generalized seizures occur, lying on side with paddling movements of the extremities and extended neck. It is important to note that the animals remain conscious despite the seizure-like symptoms, which is an important distinguishing feature from epileptic seizures.

Without treatment, eclampsia can lead to death from respiratory failure, as the respiratory muscles can also be affected by the seizures. The heart rate is typically greatly increased, the pulse strong and throbbing. The mucous membranes can be bluish due to the hypoxia.

The process is as follows:

  • initially restlessness, panting, salivation
  • Muscle Twitches
  • sawhorse-like position, head bent backwards
  • Collapse of the hind legs
  • Spread of the seizures to the entire body with lying on side, sawhorse-like extended legs and head bent backwards
  • significantly increased body temperature to >40 °C
  • Pulse throbbing, greatly accelerated
  • In severe cases, the respiratory muscles can also be affected, so that death can occur.

First Aid

  1. Remove the mother from the puppies to prevent further calcium loss through the milk
  2. The dog should also not hear the puppies in order not to provoke stimulation of milk production.
  3. Control of body temperature
  4. In case of only slight restlessness without seizures, immediate change of the dog’s diet to a calcium-rich complete food adapted for lactating dogs
  5. Intensive supplementary feeding of the puppies with puppy milk replacer and, from the 3rd week of life, with food porridge.

Diagnosis

The diagnosis of eclampsia is primarily based on the clinical presentation in conjunction with the medical history of a lactating dog or cat. The timing of the onset – typically 1–4 weeks after birth – and the characteristic neuromuscular symptoms are important diagnostic clues. A quick diagnosis is crucial, as treatment must be initiated immediately.

The definitive diagnosis is made by determining the serum calcium level, which is significantly reduced in affected animals (normal value in dogs: 2.2–2.9 mmol/l; in eclampsia often < 1.5 mmol/l). However, since treatment should not be delayed, a presumptive diagnosis is often made in practice based on the clinical picture and the rapid response to calcium therapy. Further diagnostic measures may include:

  1. Blood count and serum biochemistry to assess the general condition and to exclude other diseases
  2. Determination of ionized calcium (more precise than total calcium)
  3. Measurement of phosphorus and magnesium, as their values may also be changed in eclampsia
  4. ECG to monitor cardiac complications in severe hypocalcemia

Differential diagnosis must exclude other causes of seizures, such as epilepsy, poisoning, hypoglycemia, meningoencephalitis, or electrolyte disorders of other origins. An important distinguishing feature is that consciousness is retained despite the seizures in eclampsia.

Further veterinary measures

The treatment of eclampsia is a medical emergency and must be initiated immediately. The therapy aims to quickly normalize the calcium level in the blood and control the neuromuscular symptoms.

Emergency therapy consists of the intravenous administration of calcium solutions, typically 10% calcium gluconate at a dosage of 0.5–1.5 ml/kg body weight. This is administered slowly under ECG control, as too rapid an infusion can lead to cardiac arrhythmia. Clinical improvement usually occurs within minutes, confirming the diagnosis. In severe cases, a continuous calcium infusion may be necessary.

Accompanying measures include:

  1. Separation of the mothers from the puppies to reduce calcium loss through the milk
  2. Control of body temperature, as hyperthermia often occurs
  3. In case of severe seizures, anticonvulsants such as diazepam can be used
  4. Fluid therapy to support circulatory function
  5. Heat therapy for hypothermia or cooling for hyperthermia

After the acute phase, oral calcium supplementation is necessary for the duration of lactation. The diet should be changed to high-quality, calcium-rich feed for lactating animals. The puppies should also be fed with breast milk substitute to reduce the burden on the mother. Puppies from the third week of life can be started on supplementary feeding with food porridge.

Prophylactically, in endangered animals (small breeds, large litters, previous eclampsia), attention should be paid to a balanced but not excessive calcium supply already during pregnancy.

Prognosis and aftercare

The prognosis for animals with eclampsia is generally good with timely and adequate treatment. Most patients respond quickly to intravenous calcium therapy, with a significant improvement in clinical symptoms within minutes to hours. Without treatment, however, the disease can be fatal.

After the acute phase, careful aftercare is crucial to avoid relapses. This includes:

  1. Regular monitoring of the calcium level in the blood
  2. Continued oral calcium supplementation throughout the lactation period
  3. Adjustment of the diet with calcium-rich, high-quality food for lactating animals
  4. Management of puppy rearing, including supplementary feeding, to reduce the burden on the mother
  5. Close veterinary monitoring, especially in the first weeks after the eclampsia event

In animals that have once suffered from eclampsia, there is an increased risk of recurrence in subsequent litters. This should be taken into account in breeding decisions. In some cases, castration / neutering may be recommended after weaning the puppies, especially in animals with severe episodes or repeated incidents.

The long-term prognosis also depends on whether complications such as aspiration pneumonia, brain damage due to hypoxia, or cardiac arrhythmia have occurred during the acute phase. These complications can delay recovery or leave permanent damage.

Summary

Eclampsia is an acute, life-threatening metabolic disease in lactating dogs and cats, which is caused by a critical drop in the blood calcium level. It typically occurs in the first weeks after birth and manifests itself through progressive neuromuscular symptoms such as muscle tremors, stiffness, seizures, and hyperthermia. Small dog breeds and first-time mothers with large litters are particularly at risk.

The diagnosis is based on the clinical picture in conjunction with the medical history and is confirmed by the detection of hypocalcemia. Treatment requires immediate intravenous calcium substitution, which usually leads to rapid clinical improvement. Accompanying measures include the temporary separation from the puppies, supplementary feeding of the offspring, and the change to a calcium-rich diet.

With timely treatment, the prognosis is good, but there is an increased risk of recurrence in subsequent litters. Preventive measures such as a balanced diet during pregnancy and lactation as well as adequate calcium supplementation can reduce the risk. Eclampsia illustrates the complex physiological requirements of lactation and the importance of a balanced mineral balance for the health of mothers.

Outlook on current research

Research in the field of eclampsia in dogs and cats is currently focused on several promising areas. Newer studies are investigating the genetic basis of the predisposition of certain breeds to disorders of calcium metabolism. In the future, molecular genetic analyses could enable the identification of at-risk animals before clinical symptoms occur.

Another research focus is on optimizing peripartal nutrition. Current studies show that not only the absolute amount of calcium, but also the ratio to other minerals such as phosphorus and magnesium as well as the bioavailability are crucial. Innovative feed formulations with improved calcium sources and optimized nutrient ratios are being developed and evaluated.

The role of vitamin D metabolism in the regulation of calcium balance during pregnancy and lactation is being researched more intensively. New findings suggest that variations in the vitamin D receptor and in vitamin D-metabolizing enzymes could influence the individual susceptibility to eclampsia.

In the field of diagnostics, point-of-care tests are being developed that should enable a faster and more precise measurement of ionized calcium. These could save valuable time, especially in emergency situations, and improve therapy decisions.

Therapeutically, new formulations of calcium preparations with prolonged duration of action and improved tolerability are being researched. Alternative treatment approaches, such as the modulation of parathyroid hormone secretion or the use of vitamin D analogs, are also being investigated.

These research approaches promise to deepen our understanding of eclampsia and could lead to improved prevention and treatment strategies that better protect the health of mothers and their offspring.

Frequently asked questions (FAQs)

  1. What is the difference between eclampsia and epilepsy in dogs and cats?
    In eclampsia, the animals remain conscious despite seizures, while epileptic seizures typically involve loss of consciousness. In addition, eclampsia occurs almost exclusively in lactating animals and is caused by a low calcium level.
  2. Can eclampsia also occur before birth?
    Yes, in rare cases, eclampsia can occur in the last days of pregnancy, especially in animals with very large litters or pre-existing calcium metabolism disorders.
  3. How long do the puppies have to be separated from the mother?
    The separation should be kept as short as possible, typically 12–24 hours, until the mother’s calcium level has stabilized. After that, the puppies can be put back on under supervision, often combined with supplementary feeding.
  4. Is eclampsia hereditary?
    There is evidence of genetic factors that influence the susceptibility to disorders of calcium metabolism. Animals that have once suffered from eclampsia should therefore be used for breeding with caution.
  5. Can eclampsia be completely prevented?
    Complete prevention is not always possible, but the risk can be significantly reduced through a balanced diet, adequate calcium supplementation, and monitoring of at-risk animals.
  6. How quickly does calcium therapy work for eclampsia?
    With intravenous administration of calcium, a significant improvement in symptoms is often observed within minutes, which is an important diagnostic criterion.
  7. Can male animals also get eclampsia?
    No, eclampsia is a disease that occurs exclusively in female, lactating animals, as it is related to the increased calcium requirement during milk production.
  8. Is a special diet necessary after surviving eclampsia?
    Yes, a calcium-rich, balanced diet should be ensured throughout the lactation period, often supplemented by calcium supplements according to veterinary instructions.
  9. What is the risk of relapse in later litters?
    The recurrence risk is increased, with rates of 30–50% in subsequent litters if no preventive measures are taken. However, this risk can be significantly reduced with appropriate precautions.
  10. What long-term consequences can surviving eclampsia have?
    With prompt treatment, long-term consequences are rare. However, in severe or untreated cases, neurological damage, aspiration pneumonia, or cardiac arrhythmia can occur.

Literature

  • Gough, A., Thomas, A., & O’Neill, D. (2021). Breed predispositions to disease in dogs and cats (3rd ed.). Wiley-Blackwell.
  • Jutkowitz, L. A. (2020). Reproductive emergencies. Veterinary Clinics of North America: Small Animal Practice, 50(6), 1457–1475. https://doi.org/10.1016/j.cvsm.2020.07.007
  • Löwe, G., & Löwe, O. (2021). Notfälle bei Hund und Katze – Ein tierärztlicher Ratgeber (208 S.). Kynos-Verlag.
  • Merck & Co., Inc. (n.d.). Puerperal hypocalcemia in small animals. In Merck veterinary manual. Retrieved August 10, 2025, from https://www.merckvetmanual.com/metabolic-disorders/disorders-of-calcium-metabolism/puerperal-hypocalcemia-in-small-animals
  • Mooney, C. T., & Peterson, M. E. (2022). BSAVA manual of canine and feline endocrinology (4th ed.). British Small Animal Veterinary Association.
  • Rozanski, E. A., & Rush, J. E. (2023). Small animal emergency and critical care medicine (2nd ed.). CRC Press.
  • Waddell, L. S., & Drobatz, K. J. (2021). Calcium disturbances in critical illness. Veterinary Clinics of North America: Small Animal Practice, 51(6), 1313–1325. https://doi.org/10.1016/j.cvsm.2021.07.006