when i first saw three spittles in a row, I thought this also: 1 spittle per player
but then I tested it after one friend logged off.
every time i swapped from bear to cat and then back to bear, I kept getting new spittle casts. like 6 in a row.
it seemed that if I used shape shifting mechanics to drop the dot, I got a new spittle forced.
this did not happen when I soloed him earlier today. but in a group, it seemed haywire.