our lab had pups last november, and the vet recomended giving her 3 times as much as normal once the pups arrived,there is specialist diets around for mums, but we just kept our dog on her normal diet of meat and mixer , however we did change the mixer to complete, she stayed really healthy during and after pregnancy,and maintained a good weight, 3 days after the pups were born she was happy to go for short walks, i think this gave her a break we would not of dreamed of taking her if she hadnt of wanted to leave her pups, our previous dog would barely leave her pups sides for the first 3 weeks!our lab got sick of them at 3 weeks so we had to wean them a little earlier than planed. she had 9 pups so we constantly cleaned up after them it was hard work but worth it, however our lab has now been spayed!