Eclampsia
Eclampsia refers to seizures that can occur in female dogs before, during, and after birth. However, it most commonly affects nursing dogs from the 1st to the 4th week after giving birth. If puppies continue to nurse intensively beyond this period, eclampsia can also occur later.
Eclampsia occurs more frequently in small dog breeds such as terriers, miniature schnauzers, dachshunds, or pugs than in large dog breeds. Young female dogs are more susceptible than older ones. In cats, the condition 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 nursing female dog, the daily calcium requirement can increase four to six times the normal requirement. This increased need cannot be met by food intake alone, but also requires efficient mobilization of calcium from the bones, which is regulated by parathyroid hormone.
Several predisposing factors can lead to eclampsia:
- Insufficient calcium intake through diet during pregnancy and lactation
- Disturbed hormonal regulation of calcium balance, especially by parathyroid hormone, calcitonin, and vitamin D
- Large litters, which mean an increased calcium requirement for milk production
- Genetic predisposition in certain breeds
- 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: When there is a sudden increased need for calcium, the body cannot mobilize calcium from the bones quickly enough, leading to a critical drop in serum calcium. Since calcium is necessary for neuromuscular transmission, this deficiency results in the characteristic clinical symptoms.
Symptoms
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 early stage, the animals show restlessness, nervousness, increased panting, salivation, and an elevated body temperature (often above 40°C). The mother animals appear anxious and may neglect or reject their puppies. Increased sensitivity to external stimuli is often observed.
As the condition progresses, distinct neuromuscular symptoms appear: muscle tremors, starting at the head and face, spreading to the entire body; stiff, uncoordinated gait; muscle stiffness and tetany. Characteristic is the so-called “sawhorse stance”, where the legs are stiffly extended and the head is bent backwards.
In the advanced stage, generalized seizures occur, with lateral recumbency and paddling movements of the limbs and extended neck. It’s important to note that despite the seizure-like symptoms, the animals remain conscious, which is an important distinguishing feature from epileptic seizures.
Without treatment, eclampsia can lead to death by respiratory failure, as the respiratory muscles can also be affected by the seizures. The heart rate is typically greatly increased, with a strong and throbbing pulse. The mucous membranes may appear bluish due to hypoxia.
The sequence of events is as follows:
- initially restlessness, panting, salivation
- Muscle Twitches
- sawhorse-like stance, head bent backwards
- collapse of the hind legs
- spread of seizures to the entire body with lateral recumbency, legs extended in a sawhorse-like manner, and head bent backwards
- significantly elevated body temperature to >40°C
- pulse throbbing, greatly accelerated
- In severe cases, the respiratory muscles can also be affected, which can lead to death
First Aid
- Removing the mother from the puppies to prevent further calcium loss through milk
- The female dog should also not hear the puppies to avoid stimulating milk production.
- Monitoring of body temperature
- In case of only mild restlessness without seizures, immediate change of the female dog’s diet to a calcium-rich commercial food formulated for nursing dogs
- Intensive supplementary feeding of the puppies with puppy milk replacer and from the 3rd week of life with puppy food gruel.
Diagnosis
The diagnosis of eclampsia is primarily based on the clinical presentation in conjunction with the history of a lactating dog or cat. The timing of onset – typically 1-4 weeks after birth – and the characteristic neuromuscular symptoms are important diagnostic indicators. Rapid diagnosis is crucial, as treatment must be initiated immediately.
The definitive diagnosis is made by determining the serum calcium level, which is significantly decreased 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, in practice, a presumptive diagnosis is often made based on the clinical picture and rapid response to calcium therapy. Further diagnostic measures may include:
- Complete blood count and serum biochemistry to assess general condition and rule out other diseases
- Determination of ionized calcium (more precise than total calcium)
- Measurement of phosphate and magnesium, as their values may also be altered in eclampsia
- 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 in eclampsia, consciousness remains intact despite the convulsions.
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.
The emergency therapy consists of 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 monitoring, as too rapid infusion can lead to cardiac arrhythmias. Clinical improvement usually occurs within minutes, confirming the diagnosis. In severe cases, continuous calcium infusion may be necessary.
Accompanying measures include:
- Separation of mother animals from puppies to reduce calcium loss through milk
- Monitoring of body temperature, as hyperthermia frequently occurs
- In cases of severe seizures, anticonvulsants such as diazepam may be used
- Fluid therapy to support circulatory function
- 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. Puppies should be additionally fed with milk replacer to reduce the mother’s burden. For puppies from the third week of life, supplementary feeding with gruel can be started.
Prophylactically, for animals at risk (small breeds, large litters, previous eclampsia), a balanced but not excessive calcium supply should be ensured 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 condition can be fatal.
After the acute phase, careful follow-up care is crucial to prevent relapses. This includes:
- Regular monitoring of blood calcium levels
- Continued oral calcium supplementation throughout the entire lactation period
- Adjustment of diet with calcium-rich, high-quality food for lactating animals
- Management of puppy rearing, including supplementary feeding to reduce the strain on the mother
- Close veterinary monitoring, especially in the first weeks after the eclampsia event
Animals that have experienced eclampsia once have an increased risk of recurrence in subsequent litters. This should be considered in breeding decisions. In some cases, spaying 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 arrhythmias occurred during the acute phase. These complications can delay recovery or leave permanent damage.
Summary
Eclampsia is an acute, life-threatening metabolic disorder in lactating female dogs and cats caused by a critical drop in blood calcium levels. It typically occurs in the first weeks after birth and manifests 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 temporary separation from the puppies, supplementary feeding of the offspring, and switching 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 appropriate calcium supplementation, can reduce the risk. Eclampsia illustrates the complex physiological demands of lactation and the importance of a balanced mineral metabolism for the health of mother animals.
Outlook on current research
Research in the field of eclampsia in dogs and cats is currently focusing on several promising areas. Recent studies are investigating the genetic basis of certain breeds’ predisposition to calcium metabolism disorders. In the future, molecular genetic analyses could enable the identification of at-risk animals before clinical symptoms appear.
Another research focus is on optimizing peripartal nutrition. Current studies show that not only the absolute amount of calcium but also its ratio to other minerals such as phosphorus and magnesium, as well as 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 regulating calcium balance during pregnancy and lactation is being more intensively researched. New findings suggest that variations in the vitamin D receptor and vitamin D-metabolizing enzymes could influence individual susceptibility to eclampsia.
In the field of diagnostics, point-of-care tests are being developed to enable 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 extended duration of action and improved tolerability are being researched. Alternative treatment approaches, such as 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 mother animals and their offspring.
Frequently asked questions (FAQs)
- What is the difference between eclampsia and epilepsy in dogs and cats?
In eclampsia, animals remain conscious despite seizures, while epileptic seizures typically involve loss of consciousness. Additionally, eclampsia occurs almost exclusively in lactating animals and is caused by low calcium levels. - Can eclampsia 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. - How long do the puppies need to be separated from the mother?
The separation should be kept as short as possible, typically 12-24 hours, until the mother’s calcium levels have stabilized. Afterwards, the puppies can be reintroduced under supervision, often combined with supplementary feeding. - Is eclampsia hereditary?
There are indications of genetic factors that influence the susceptibility to calcium metabolism disorders. Animals that have once suffered from eclampsia should therefore be used for breeding with caution. - Can eclampsia be completely prevented?
Complete prevention is not always possible, but the risk can be significantly reduced through balanced nutrition, appropriate calcium supplementation, and monitoring of at-risk animals. - How quickly does calcium therapy work in eclampsia?
With intravenous administration of calcium, a significant improvement in symptoms is often observed within minutes, which is an important diagnostic criterion. - Can male animals also develop eclampsia?
No, eclampsia is a condition that occurs exclusively in female, lactating animals, as it is associated with the increased calcium demand during milk production. - Is a special diet necessary after recovering from eclampsia?
Yes, throughout the entire lactation period, attention should be paid to a calcium-rich, balanced diet, often supplemented with calcium preparations as per veterinary instructions. - How high is the risk of recurrence in later litters?
The risk of recurrence is elevated, with rates of 30-50% in subsequent litters if no preventive measures are taken. However, with appropriate precautions, this risk can be significantly reduced. - What long-term consequences can a survived eclampsia have?
With prompt treatment, long-term consequences are rare. In severe or untreated cases, however, neurological damage, aspiration pneumonia, or cardiac arrhythmias may occur.
Literature
- Löwe, G. and Löwe, O., 2021. Emergencies in Dogs and Cats – A Veterinary Guide. Kreuztal: Kynos-Verlag. 208 pp.
- https://www.merckvetmanual.com/metabolic-disorders/disorders-of-calcium-metabolism/puerperal-hypocalcemia-in-small-animals
- Waddell LS, Drobatz KJ. Calcium Disturbances in Critical Illness. Veterinary Clinics of North America: Small Animal Practice. 2021;51(6):1313-1325.
- Gough A, Thomas A, O’Neill D. Breed Predispositions to Disease in Dogs and Cats. 3rd ed. Wiley-Blackwell; 2021.
- Jutkowitz LA. Reproductive Emergencies. Veterinary Clinics of North America: Small Animal Practice. 2020;50(6):1457-1475.
- Mooney CT, Peterson ME. BSAVA Manual of Canine and Feline Endocrinology. 4th ed. British Small Animal Veterinary Association; 2022.
- Rozanski EA, Rush JE. Small Animal Emergency and Critical Care Medicine. 2nd ed. CRC Press; 2023.
Cat mother caring for her kitten