(Milk Fever or Puerperal Tetany)

Eclampsia, or milk fever, is an acute, life-threatening condition which attacks a brood bitch about 3 to 4 weeks after whelping puppies. It is more common in the small breeds of dogs that have had large litters.

People often give their brood-bitch heavy calcium supplements during her pregnancy, however this does not prevent eclampsia, and can actually cause it to reoccur during future pregnancies.

Canine Eclampsia, also erroneously called "milk fever", is a startling and dangerous condition brought on by extremely low levels of calcium in the blood stream. Also called hypocalcemia and puerperal tetany, I consider these episodes emergencies so the patient is admitted as soon as possible.

Most commonly seen in small to mid-sized bitches a few weeks after whelping, this condition should be watched for closely. A typical call to my office goes like this:

"Doctor, my four year-old Schnauzer whelped five puppies two weeks ago. She was fine until today when she started pacing and didn't want to nurse. Now she's worse and panting, shaking all over, and can't even stand up."

The following is a brief outline of what the typical case of Canine Eclampsia looks like:


  • Muscle tremors, restlessness, panting, incoordination, grand mal seizures and fever as high as 106


Hypocalcemia (low blood calcium) brought on by the following:

  1. Poor Nutrition - "Home brewed" diets usually are at fault. The owner innocently may be adding too much unbalanced meat to the bitch's diet, thinking the extra protein is beneficial. What's really happening is the calcium to phosphorus ratio is out of balance because the amount of useful calcium in the food is actually reduced! The ideal contains a ratio of calcium to phosphorus of 1.2 to 1. (Many organ meats such as liver have a ratio of calcium to phosphorus of 1 to 15!! Liver is great for dogs but if it comprises a large part of the diet, the calcium/phosphorus ratio of the diet will be improper.)

  2. Low Blood Levels of Albumen - Dietary protein deficiency or excessive loss from the body of albumen, which happens in some kidney diseases, will cause low levels of calcium.

  3. Disease of the Parathyroid Glands - This condition is quite rare.

  4. Excessive Milk Production - When pups require large amounts of milk (10 to 30 days post whelping) the bitch's ability to maintain proper amounts of calcium in her blood stream becomes stressed. Milk production has priority over the blood stream for calcium!


  1. I. V. Catheter for a slow, careful injection of a calcium solution under the close supervision of the veterinarian. Give too much and severe cardiac arrhythmia may occur.

  2.  I.V. dextrose for quick energy. By this time the bitch will be thoroughly exhausted due to the muscle tremors and a quick supply of energy is very helpful.

  3. Mild sedation may be required.

  4. Cool bath to lower body temperatures to normal.

NOTE: If there is time, your vet may take a blood sample prior to treatment for a thorough analysis of the bitch's blood chemistry. Quick action is very important and careful administration of medications is required. Generally, the patient stabilizes within ten or fifteen minutes and the temperature is reduced to normal via the cool bath.


  1. High quality meat-based quality food but don't over supplement with all sorts of Calcium or unbalanced meat products.

  2. Add a balanced source of calcium, phosphorus, and Vitamin D to the bitch's diet beginning about mid-term. The best sources are milk (withdraw if this causes a loose stool) or cottage cheese. DO NOT add calcium alone!! It MUST be used with phosphorus and Vitamin D. (Remember that optimum ratio of Calcium to Phosphorus of 1.2 to 1!) 

  3. Sometimes cortisone is very helpful in preventing Canine Eclampsia - ask your veterinarian about having some on hand prior to the next whelping.

  4. Supplement the puppies' intake with a milk replacer as soon as possible to decrease the milk demands on the bitch.

  5. Wean the pups as soon as possible.

Canine Eclampsia... Hypocalcemia... Puerperal tetany... Milk Fever... fancy names for a not-so-fancy disorder. Be on the alert and call your vet if you become suspicious your bitch is having trouble. Never underestimate the importance of a high quality, meat-based diet for your dog.

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This condition is seen primarily in small breed dogs nursing large litters during the first 2 - 4 weeks of lactation (nursing), when they are under the heaviest stress due to the large volume of milk needed. It also may be seen at or near parturition, or whelping.

Serum calcium levels fall to about 4 - 7 mg/dl (normal = 9 - 11 mg/dl). The dog shows trembling and weakness. As the condition progresses, dilation of the dog's pupils, elevated pulse rate, elevated body temperature, and eventually, convulsions may be seen.

Treatment includes removal of the pups from the bitch for 12 - 24 hours and administration of calcium gluconate solution slowly administered by your veterinarian. Calcium must be given slowly as too rapid infusion can cause heart abnormalities, such as arrhythmias and slowing of the heart rate. Follow-up therapy includes administration of calcium gluconate under the skin, and oral therapy with calcium compound and vitamin D. Recurrence in the same (or a subsequent) lactation is common. Wean the pups only if more than one clinical episode occurs within a lactation.

Some people feel that post-partum hysteria (savaging of pups) may be a manifestation of eclampsia. Ensure that the bitch is on a well-balanced ration.

Eclampsia (convulsions not associated with other cerebral conditions such as epilepsy or cerebral haemorrhage) can occur in the dog as a result of lactation. The greater the quantity of milk produced, the more likely it is that eclampsia will occur. When calcium is lost in the milk faster than it is absorbed, or than it can be mobilized from the skeletal system, hypocalcemia results. Signs are muscle fasciculations, tetany, and death. The treatment is to slowly (10-15 min) administer a calcium solution intravenously. As you treat, the amplitude of heart sounds will increase, and the heart rate will decrease. If the heart rate increases, or becomes arrhythmic immediately stop calcium administration. 

A bitch with a large litter two to four weeks into lactation is especially susceptible to eclampsia. Some would suggest giving extra Ca prior to the time it is needed. However, this does not help, because excess Ca intake decreases the efficiency of Ca absorption from the intestine, inhibits parathyroid hormone secretion, and stimulates thyrocalcitonin secretion. These changes decrease the ability of the dog to mobilize Ca from the bone, when additional Ca is needed; it takes 1 to 3 weeks to reverse the effects. Of course, this is not fast enough, and hypocalcemia and eclampsia occur. Giving Ca when it is needed, during the first week through the fourth or fifth week of lactation, may be helpful; 500 mg of calcium carbonate (about one Tums, the antacid you take for upset stomach) per 5 kg of body weight per day, but only for the bitch in which eclampsia has previously occurred. The best treatment is to get the puppies off the dam as quickly as possible, either onto solid food or a bitch's milk replacer.


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