Postpartum Eclampsia in Cats
Eclampsia is a deficiency of blood calcium (hypocalcemia) that develops in the weeks after giving birth, although it may develop prior to birth or during lactation. Also called "milk fever," eclampsia is usually due to an underactive parathyroid gland, the gland that is responsible for regulating the parathyroid hormone, which in turn regulates the amount of calcium that is stored in the bones, to be removed as needed for use in the blood. As the parathyroid gland has not being signaled to stimulate the parathyroid hormone to release calcium from the bones into the body, when the nursing queen's milk comes in and the demand for calcium suddenly increases, the parathyroid gland is unable to respond quickly enough for her needs to be met. The lack of calcium results in tonoclonic contractions of the skeletal muscles, where the muscles in the body contract convulsively, limiting movement.
Kittens are often not affected by eclampsia because their nutritional needs, including calcium, are being taken care of by their mother. In addition, symptoms in the nursing queen typically become apparent in the first 40 days after giving birth.
Symptoms and Types
- Poor maternal behavior
- Restlessness, nervousness
- Panting, whining
- Clumsy walking, stiff gait
- Facial itchiness
- Muscle tremors, tetany (entire body goes stiff), convulsions
- Cat lies down with paws rigidly extended (usually seen 8–12 hours after the first onset of symptoms)
- High body temperature, fever over 105 degrees Fahrenheit
- Rapid, heavy breathing
- Dilated pupils which are slow to contract when exposed to light
- Calcium supplementation during pregnancy
- Inappropriate calcium to phosphorous ratio in the diet while pregnant
- Poor nutrition during pregnancy
- First litter
You will need to provide a thorough history of your cat's health leading up to the onset of symptoms. Make sure to provide your veterinarian with the type of pregnancy supplement you have been giving to your cat, and details of the diet you have been feeding her.
Standard tests will include a chemical blood profile, complete blood count and an electrolyte panel. As soon as the electrolyte panel is ready, the total serum calcium will be verified by a blood test. If the concentration is less than 7 mg/dL, your cat will be diagnosed with eclampsia and will be given calcium supplementation immediately. Low blood sugar and low blood magnesium levels may also be present. These can also be supplemented. Serum potassium is high in 56 percent of cases. An electrocardiogram (ECG) showing the heart's electrical rhythm will often be abnormal.