Thank you all for your thoughts, very much appreciated!
I do not doubt that my dogs were made in Murano. And comparing it to the signed dogs I linked to, I think very likely by Elio Raffaeli -- though I am aware that he seems to have worked at Cenedese, Livio Seguso and others, so his designs sometimes resemble pieces by those makers...
They are definately not Czech.
I have never come across a piece of ZBS glass in Heliolite. But you never know

m: your bowl seems to show a similar colour change, so I would think that it was Heliolite glass as well (but maybe in a different mix). Doesn't look Czech to me either.
Anne: thanks for the links! The dog is similar indeed, but the Raffaeli dogs are a far better match. Unfortunately that label doesn't help either.
I took a quick pic of my Heliolite dog with flash, showing the "daylight" colour better.
Michael