Clear/foamy vomit usually means bile..which could be from many different things I suppose- but in our case, it usually means Moose has an empty stomach. What time of day in relation to when he is eating could be a clue that it has to do with empty stomach. Moose would mostly do it early in the morning, before he had eaten anything. Sometimes it's hard to get them to eat after they vomit the clear/foamy liquid so I usually feed boiled chicken and rice to get his tummy ok again. Of course a vet can tell you best but hope this helps!
