Female Valley Bulldog
 

Reproduction and lactation place additional nutritional demands on the female dog (bitch). During this time, the diet must supply all the vitamins, minerals and calories needed to meet the requirements of the bitch, and also must support fetal growth during pregnancy, and milk production after the birth of puppies. Because of the high calorie requirements, the diet should be highly palatable, energy dense, with high digestibility.

During the early stages of pregnancy, fetal growth is slow, and the bitch does not require any additional calories over the maintenance level. It is important to avoid overfeeding during early gestation, since too many calories at this time can cause the bitch to become overweight, and may contribute to whelping problems. Most fetal weight gain occurs during the last third of gestation, and the energy requirement of the bitch will increase during that time. During the fifth week of gestation, 15% more calories should be provided, and an extra 15% calories should be added each week until the end of gestation. Thus by the time the puppies are born, the bitch should be eating 60% more calories than she did during the early stages of pregnancy. 

If the bitch is carrying a large litter, it may be physically difficult for her to increase the quantity of food consumed enough to meet her added nutritional requirements. Switching to a diet that is higher in protein and fat will be more calorie dense, and therefore less of this diet will have to be fed to meet her needs. A highly digestible and palatable food designed for puppies is a good choice during late lactation, since it will contain more calories per cup than an adult maintenance-type diet. Several small meals should be fed during the day since her stomach capacity is limited due to the large uterus. 

Milk production places the largest nutritional demands on the dam. She must metabolize very large amounts of nutrients in order to produce sufficient milk to support the growth of her puppies. Dams with a large litter may require four times more calories during lactation than they needed for maintenance. Peak milk production occurs when the puppies are 4 to 5 weeks of age, right before they are weaned. 

Consider a Labrador Retriever dam weighing 62 lbs nursing a litter of six 4-week-old puppies that weigh 5.5 lbs each. Each puppy requires approximately 500 kcal/day, which must be supplied by the dam's milk. Therefore the dam must supply 3000 kcal/day as milk. Dam's milk contains about 1300 kcal/liter (39 kcal/ounce), and therefore she must produce at least 2.3 liters (76.5 ounces) of milk each day to feed her puppies. To produce this many calories in milk, she will have to consume 4000 kcal/day from her food, since some energy is lost in milk production. To maintain her own body weight, she needs her usual maintenance amount of approximately 1500 kcal/day. Thus her total intake needs to be 5500 kcal/day, which is about 4 times her normal maintenance requirement. If the litter is larger, she will require even more calories per day. To consume this large an amount of calories, the dam needs to be eating a very energy dense, and highly digestible diet. If she does not consume the calories necessary, she will lose body condition, and may not produce adequate milk to feed her puppies. 

In addition to increased calorie needs during gestation and lactation, the quantity of protein required is also increased. Both protein quality and quantity will affect milk production, and thus it is very important to feed a diet containing protein from highly digestible ingredients. Egg protein is considered the most digestible protein. Meat source proteins are more digestible than are cereal proteins, such as soybean meal and corn gluten meal. Chicken by-product meal is more digestible than is meat and bone meal, since meat and bone meal contains more non digestible bone. Therefore diets containing highly digestible chicken by-product meal as the major protein source will provide the highest amount of digestible protein. Different studies have shown that the protein requirement during pregnancy and lactation is between 25 and 30%. Thus a high calorie puppy food or athletic-type food if fed in sufficient quantities, will provide the quantity of protein needed. Weaning should be a gradual process so that milk production gradually decreases. At approximately 3 to 3 + weeks of age, puppies can be introduced to ground or softened puppy food that has been moistened with warm water. The age of weaning depends on the size of the litter, and on the quantity of milk the dam is producing. As the puppies are eating more solid food, the quantity fed to the dam can be gradually decreased so that she is back to her maintenance level of food by the time puppies are fully weaned. However, if the dam has lost some body weight or condition during lactation, she will require extra calories to regain the body weight she has lost. 

Patricia Schenck, DVM, PhD
Veterinary Nutritionist