Anemic puppies

Question
We have lost four litters of terrier pups over a years time and a 2 yr old coonhound due to a mysterious illness.  We tested the dogfood--inconclusive.  We did bloodtests, found the pups anemic, which we already knew.  No parvo, etc.  Pups suddenly become lethargic, thin, dehydrated, anemic, won't eat/drink.  Dead w/in 2 days. Our vet is stumped, and so are we.  I have three now on fluids and antibiotics, three that will probably be sick tomorrow.  Sold pups that are in homes are healthy, no illness.  All are now 12 wks, shots, wormed 3x.  What should we try or look for?!  Could it be our public water, which has been proven to have contaminants, yet considered safe for human consumption. Loose (adult farm) dogs drink from pond, puddles, etc.  All are healthy.  Pups, confined, chained dogs are ill--all drink public water.  Please offer suggestion!  Help!

Answer
Well I think the next thing is to find the confined dogs a different source of water, even dip it out of the pond or buy bottled water.  Our Wal-Mart charges 33 cents a gallon if you bring yur own jugs.  I would also suspend breeding until the problem is solved.  

Note http://www.dogsdeservebetter.org/home.html