For eons, mother’s milk has proven to be the best
food for newborns. Studies in several species have documented the mechanisms that keep milk high in
nutritional value regardless of the condition of the dam.
These studies verify that a lactating bitch will produce a
sufficient quantity of nutritious milk to support her puppies even if her condition deteriorates. For conscientious dog
breeders, the challenge is to provide nutrition for the dam that will allow her to not only feed her puppies, but also to
maintain her own condition.
It is normal for a bitch to lose some bodyweight
during lactation but, ideally, the amount lost should not exceed 10% of her original
weight. It is much easier to attain this goal if the bitch is in good condition prior to
whelping which usually reflects the fact that she was in good condition at mating.
Excellent nutrition, though crucial, is not the only
step that breeders can take to insure a healthy dam after her puppies are whelped. Clean, dry facilities are
important. Daily exercise and fresh air can make the nursing process more pleasant for
the dam, too. Daily examination of the dog’s mammary glands allows early detection of infection
in the breasts allowing prompt treatment.
Of course, a plentiful supply of clean water is very important to the well-being of the dam.
Water consumed by the bitch is important to the puppies as well because water turnover is very high in the newborn
puppy. This function of nursing is often overlooked by breeders. A consistent fluid intake by the puppy is required
to maintain blood volume and this hydration function of milk is as important as the nutritional role.
DOG MILK CHANGES OVER THE NURSING PERIOD
One of the fascinating features of the nursing process is the ability of milk to change over the lactation.
For example, the energy content of dog milk increases steadily for the first 40 days of nursing then decreases by
day 50, coinciding with the puppies’ ability to eat solid food. This allows an early start on shrinkage of mammary
tissue to help the bitch end her milk production.
Fat content in the milk varies over the lactation period as
well. Early in lactation, the fat level is about 2.4%. By the middle of the nursing period, the fat level increases to
about 5% then decreases to about 2.6% near weaning.
Calcium is high in milk during the entire nursing period
but continues to increase as weaning nears. Magnesium, iron, and zinc all vary over the lactation stage.
It is important to note that the dam’s nutritional
level must be very high in order to allow this normal variation of nutrients and to provide optimal nutrition for
the puppies. A specific example is the so-called “toxic milk” syndrome, which can affect puppies between 3 and 14 days
of age. This condition may be caused by uterine infection and/or mammary infection, but some cases respond to zinc
supplements suggesting that the disorder may be due, in part, to inadequate zinc
intake. This example illustrates the necessity of a high nutritional plane to supply the
various nutrients required by the nursing bitch.
Failure to consume colostrum during the critical
period when the intestine is open to intact protein
absorption seriously compromises the immune status of the neonatal puppy. This occurs either through the bitch’s
inability to produce colostrum or the puppies’ inability to nurse properly. Suitable corrective action requires the
manual collection of colostrum from another bitch or a frozen source, then provision to the puppy via stomach
Although much less desirable, colostrum from another species (eg, bovine) may be used. The antibodies provided by cattle colostrum may not be protective for the puppy, but other
non-specific defences may be utilized (lysosyme, lactoferrin, and
oligosaccharides). These nutrients protect the puppy against bacteria by destroying the pathogen or protecting the puppies intestine against bacterial toxins.