Pregnant and nursing dams: energy and nutrient requirements

The pregnant and nursing bitch is a nutritional case like no other. The dam's body is supporting the development of the puppies in utero (the gestation), the production of the milk for the newborn puppies (the lactation), and the recovery from the pregnancy and the delivery (the involution). The dam's nutritional requirements change dramatically over the course of the pregnancy and the lactation, and the dam's nutritional management is one of the most important determinants of the litter size, the puppy vigor, the milk production, and the dam's recovery. The dam that is fed the right diet, in the right amount, at the right time, is the dam that produces a large, healthy litter, that produces a strong milk supply, and that recovers quickly after the weaning. The dam that is fed the wrong diet, or the right diet in the wrong amount, is the dam that produces a small, weak litter, that produces an inadequate milk supply, and that is at risk of the metabolic crisis (the eclampsia, the mastitis, the weight loss) that is the preventable consequence of the poor nutrition.

This article is going to walk you through the practical energy and nutrient requirements of the pregnant and nursing bitch — the caloric increase across the pregnancy and the lactation, the protein and fat profiles, the calcium and the phosphorus, the feeding schedule, the weaning transition, the common mistakes, and the four errors that turn the critical window into a reproductive disaster. I am a small-animal veterinarian with a focus on clinical nutrition, and the reproductive nutrition is one of the most important topics I cover with my breeding clients. The cases that go well share a common feature: the owner has understood the changing nutritional requirements, has adjusted the diet through the pregnancy and the lactation, and has managed the weaning transition carefully. The cases that go poorly share a different common feature: the owner has fed the same diet throughout, has not adjusted the amount or the type, and has produced the metabolic crisis that the proper nutrition would have prevented.

I want to be clear at the start: the reproductive nutrition is a well-studied area of veterinary nutrition, and the published guidelines (from the National Research Council, the American College of Veterinary Nutrition, and the major pet food manufacturers) are consistent. The right diet at the right amount at the right time produces the best outcomes. The wrong diet, the wrong amount, or the wrong time produces the metabolic consequences that are preventable. The right approach is the evidence-based approach.

The energy requirements, by stage

The energy requirements of the dam change dramatically over the course of the pregnancy and the lactation, and the changes are the most important variables to manage.

The first 4 weeks of gestation (the early pregnancy). The energy requirements are essentially the same as the maintenance requirements. The embryo is small, the fetal growth is minimal, and the dam's metabolic demand has not yet increased. The dam should be fed at the maintenance level, with a high-quality adult maintenance diet, and the dam should be monitored for the body condition (the dam should be at the target BCS of 4.5–5/9, and the dam should not be overfed at this stage).

The last 5 weeks of gestation (the late pregnancy, days 29–63). The energy requirements increase gradually, reaching about 1.25–1.5x the maintenance by the time of the whelping. The fetal growth is the most rapid in the last 3 weeks, and the dam's metabolic demand increases correspondingly. The dam should be transitioned to a high-quality growth or performance diet (a puppy food, ideally) by week 5 or 6 of gestation, and the dam should be fed the increasing amount to support the fetal growth. The dam should be gaining weight (the dam should be gaining 15–25% of the non-pregnant body weight by the time of the whelping), and the dam's body condition should be monitored.

The first 4 weeks of lactation (the peak lactation, weeks 1–4). The energy requirements are the highest of any life stage. The lactating dam's energy requirements can be 2–4x the maintenance, depending on the litter size (the larger the litter, the higher the energy demand). The dam should be fed the high-quality puppy food ad libitum (as much as the dam wants to eat), with the food available at all times, and the dam should be monitored for the body condition (the dam should not be losing weight, and the dam should be eating enough to maintain the body condition).

The weaning (weeks 4–8 of lactation, the gradual transition). The energy requirements decrease gradually as the puppies begin to eat solid food, and the dam's food intake can be reduced gradually. The dam should be transitioned back to the maintenance diet over 1–2 weeks, and the dam should be monitored for the body condition (the dam should not be losing weight, and the dam's BCS should be gradually returning to the target).

The post-weaning (weeks 8+ of lactation, the recovery). The energy requirements are the maintenance levels, and the dam should be fed the maintenance diet at the maintenance amount. The dam's BCS should be monitored for the gradual return to the pre-pregnancy BCS, and the dam should be exercised appropriately to support the recovery.

The protein and fat profiles

The protein and the fat are the macronutrients that support the fetal development, the milk production, and the dam's recovery.

The protein. The protein requirements during the late gestation and the peak lactation are higher than the maintenance. The dam should be fed a diet with 28–32% protein on a dry-matter basis, with the protein being high-quality and highly digestible (the animal-based protein, the named-source protein, the protein with the appropriate amino acid profile). The lysine, the methionine, and the arginine are the amino acids that are particularly important for the fetal development and the milk production, and the high-quality protein source provides the amino acids in the right ratio.

The fat. The fat requirements during the late gestation and the peak lactation are also higher than the maintenance. The dam should be fed a diet with 18–22% fat on a dry-matter basis, with the fat being the right balance of the omega-6 to the omega-3 (the omega-3 fatty acids, as I described in the joint health article, have the anti-inflammatory effects and the neurodevelopmental effects that are important for the puppies). The fat is the most calorie-dense macronutrient, and the higher fat content allows the dam to meet the high energy demand without the excessive food volume.

The puppy food as the right choice. The puppy food (a growth or performance diet, designed for the puppies and the lactating dams) is the right choice for the late gestation and the peak lactation. The puppy food has the higher protein (28–32% DM), the higher fat (18–22% DM), the appropriate calcium-to-phosphorus ratio (1.2:1 to 1.4:1), the DHA (for the puppy neurodevelopment), and the higher caloric density. The puppy food is appropriate for the dam from the late gestation through the weaning, and the puppy food is the right transition back to the maintenance diet at the weaning.

The calcium and the phosphorus

The calcium and the phosphorus are the minerals that are most commonly mismanaged in the pregnant and the nursing dam, and the mismanagement can produce the eclampsia (the hypocalcemia, the "milk fever") that is one of the most common emergencies in the late gestation and the early lactation.

The calcium requirements. The calcium requirements during the late gestation and the peak lactation are higher than the maintenance, because the calcium is being transferred to the developing fetuses (the bone mineralization) and to the milk (the calcium content of the milk is significant, especially for the rapid bone growth of the puppies). The dam should be fed a diet with 1.0–1.5% calcium on a dry-matter basis, and the calcium-to-phosphorus ratio should be 1.2:1 to 1.4:1.

The calcium supplementation myth. The traditional belief (and the traditional veterinary recommendation) was that the pregnant and the nursing dam should be supplemented with the oral calcium, to prevent the eclampsia. The modern understanding (based on the published research over the last 20 years) is that the oral calcium supplementation during the late gestation and the early lactation is not protective against the eclampsia, and the oral calcium supplementation may actually increase the risk of the eclampsia (by suppressing the dam's parathyroid hormone production, which is the hormone that mobilizes the calcium from the bones when the serum calcium drops). The right approach is to feed a balanced diet with the appropriate calcium content, and to not supplement the oral calcium during the late gestation and the early lactation. The dam that develops the eclampsia is a dam that needs the intravenous calcium (administered by the vet), and the dam that develops the eclampsia is not a dam that is protected by the oral calcium supplementation.

The eclampsia: the signs and the emergency response. The eclampsia (the hypocalcemia) typically occurs in the late gestation (the last 2 weeks) or the early lactation (the first 3–4 weeks), and the signs are:

• Restlessness, pacing, panting.

• Muscle tremors, stiffness, weakness.

• Seizures (in severe cases).

• High fever (the body temperature may rise to 104–106°F).

• Death, if not treated promptly.

The eclampsia is a true emergency, and the dam needs the intravenous calcium immediately. The owner of a pregnant or nursing dam should know the signs, and the owner should have the emergency vet's contact information readily available. The eclampsia is the most common reason for the emergency vet visit in the late gestation and the early lactation, and the eclampsia is the most preventable emergency with the appropriate diet.

The feeding schedule

The feeding schedule is the practical implementation of the energy and the nutrient requirements.

The late gestation (weeks 5–9). The dam should be fed the puppy food, with the amount increasing gradually from 1.0x the maintenance (week 5) to 1.5x the maintenance (week 9). The feeding should be split into 2–3 meals per day, and the dam should be monitored for the appetite (the dam's appetite typically increases in the last 3 weeks, and the increased appetite is a sign that the dam is supporting the fetal growth).

The first 4 weeks of lactation. The dam should be fed the puppy food ad libitum, with the food available at all times. The dam's appetite is at its peak during the peak lactation, and the dam may be eating 2–4x her maintenance amount. The feeding should be split into 3–4 meals per day, and the food should be available in the whelping area (the dam should not have to leave the puppies to eat). The water should be available at all times, and the water intake should be the dam's high water intake (the lactating dam drinks 2–3x her maintenance amount, to support the milk production).

The weaning (weeks 4–8). The dam's food intake can be reduced gradually as the puppies begin to eat solid food. The reduction should be 10–20% per week, and the dam should be monitored for the milk production (the milk production should decrease as the puppies eat more solid food, and the dam's mammary glands should gradually involute). The dam's BCS should be monitored, and the dam should be returned to the maintenance diet and the maintenance amount over 1–2 weeks.

The common mistakes

The common mistakes in the pregnant and the nursing dam nutrition, in summary:

• Feeding the maintenance diet throughout. The maintenance diet is appropriate for the early gestation, but the maintenance diet is not appropriate for the late gestation and the peak lactation. The dam needs the higher protein, the higher fat, the higher calcium, and the higher caloric density of the puppy food.

• Overfeeding in the early gestation. The owner assumes that the pregnancy means the dam should be fed more from the start, and the owner produces an overweight dam by the mid-gestation. The over-conditioning in the early gestation produces the difficult whelping and the metabolic stress.

• Underfeeding in the peak lactation. The owner assumes that the dam's appetite is the indicator of the caloric need, and the dam that is producing a large litter is not eating enough to support the milk production. The result is the dam's weight loss, the dam's poor body condition, and the inadequate milk production.

• Calcium supplementation during the late gestation. The owner is supplementing the oral calcium in the mistaken belief that the supplementation will prevent the eclampsia, and the owner is actually increasing the eclampsia risk.

• Abrupt weaning. The owner separates the dam from the puppies abruptly, and the dam's mammary glands become engorged, and the dam is at risk of the mastitis. The weaning should be gradual over 1–2 weeks.

The four errors that turn the critical window into a reproductive disaster

Error 1: Not transitioning to the puppy food in the late gestation. The most common error. The owner is feeding the maintenance diet throughout the pregnancy, the fetal growth is not supported by the diet, and the puppies are born smaller and weaker than they should be. The fix is the transition to the puppy food by week 5 or 6 of gestation.

Error 2: Not feeding the dam ad libitum during the peak lactation. The second most common error. The owner is feeding the dam a measured amount, and the dam is producing a large litter, and the dam is not eating enough to support the milk production. The dam loses weight, the milk production drops, the puppies fail to thrive. The fix is the ad libitum feeding during the peak lactation, with the food available at all times.

Error 3: Not recognizing the early signs of the eclampsia. The third error. The dam is in the late gestation or the early lactation, the dam is showing the early signs of the eclampsia (the restlessness, the panting, the muscle tremors), and the owner does not recognize the signs, and the dam progresses to the seizures. The fix is the education of the owner, the awareness of the signs, and the prompt emergency vet visit.

Error 4: Abrupt weaning. The fourth error. The owner separates the dam from the puppies at 6 weeks, the dam's mammary glands become engorged, and the dam is at risk of the mastitis. The fix is the gradual weaning over 1–2 weeks, with the dam's food intake gradually reduced, and the dam's mammary glands gradually involuting.

The bottom line

The pregnant and the nursing dam is a nutritional case that requires careful management, and the management is the difference between the large, healthy litter and the small, weak litter. The right diet is the puppy food, transitioned in the late gestation, fed ad libitum during the peak lactation, and gradually reduced during the weaning. The right amount is the published amount for the dam's stage, the right frequency is 2–4 meals per day, and the right monitoring is the weekly weigh-in and the BCS check.

The dam that is well-nourished is a dam that produces a healthy litter, that produces a strong milk supply, and that recovers quickly after the weaning. The dam that is poorly nourished is a dam that produces a weak litter, that produces an inadequate milk supply, and that is at risk of the metabolic crisis. The difference is the nutrition. The nutrition is the framework above. The framework, applied with discipline, is the right prevention.

The puppies that are born to a well-nourished dam are puppies that are getting the best possible start in life. The puppies that are born to a poorly nourished dam are puppies that are starting life at a disadvantage. The difference is the dam's nutrition. The dam's nutrition is the framework above. The framework, applied with discipline, is the right prevention.

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About the author

Sarah Chen, DVM, is a small-animal veterinarian with a focused clinical interest in canine and feline clinical nutrition, with a particular interest in the nutritional management of the breeding bitch, the pregnant bitch, and the lactating bitch. She works in general practice in the Pacific Northwest and writes regularly on the practical intersections of food, life stage, and reproductive success.