This section is from the book "The Dogs Of Great Britain, America, And Other Countries. Their Breeding, Training, and Management in Health and Disease", by John Henry Walsh (Stonehenge). Also available from Amazon: The Dogs Of Great Britain, America And Other Countries.
"When it is clearly ascertained that the bitch is in whelp, the exercise should be increased and carried on freely until the sixth week, after which it should be daily given, but with care to avoid strains either in galloping or jumping. A valuable bitch is often led during the last week, but some way or other she should have walking exercise to the last, by which in great measure all necessity for opening medicine will be avoided. During the last few weeks her food should be regulated by her condition, which must be raised if she is toe low, or the reverse if she is too fat, the desired medium being such a state as is compatible with high health, and not tending towards exhaustion or inflammation. Excessive fat in a bitch not only interferes with the birth of the pups, but also is very liable to interfere with the secretion of milk, and, if this last does occur, it aggravates the attendant or "milk" fever. To know by the eye and hand how to fix upon this proper standard, it is only necessary to feel the ribs, when they should at once be apparent to the hand, rolling loosely under it, but not evident to the eye so as to count them.
It is better to separate the bitch from other dogs during the last week or ten days, as she then becomes restless, and is instinctively and constantly looking for a place to whelp in, whereas, if she is prevented from occupying any desirable corner she is uneasy. At this time the food should be of a very sloppy nature, chiefly composed of broth, or milk and bread, adding oatmeal according to the state of the bowels.