of course it's me getting it all mixed up
and you just got me back on track

the nematodes are subcutaneous
they have an indirect life cycle
they release their eggs through blisters in the skin, that burst open
in captivity, there is no intermediate host
so treatment is not necessary

however, there are skin lesions associated with the blisters bursting
one of my snakes had one blister (now open) and a couple of lesions
the others had some recently healed lesions

the snake with the fresh lesions is also the skinny one who got the dose of dog food yesterday

thanks Roy