treatment that I know of which has shown good results in clearing the organism in reptiles. The drug of choice is called hyperimmune bovine colostrum, and it apparently cleared crypto in at least 50% of the snakes studied. It was written up by Cranfield and Graczyk in 1999. It's very preliminary, but it does appear to work.
And I know that many snakes can carry and shed the organism, but don't necessarily become clinically ill. There was another study, I believe, at the Baltimore Zoo, where many, many snakes were carriers, but very limited numbers ever died or showed signs of sickness caused by the protozoan.
One problem with detecting Cryptosporidium serpentis in snakes, is that snakes also can shed mammalian crypto (from their rodent-diet), C. parvum, I think it's called, which isn't infectious to snakes. And any good diagnostic lab should be good enough to tell the two species apart.
Hope that helps.
If your veterinarian needs to read this stuff, tell him to pull out his 2006 edition of Mader's book, NOT the 1996 edition.
Take care.
DR
Suboc.com