There are two plans that I know of, but there may now be others; search for 'Tierversicherung' (German) or assurance pour animaux (French).
Epona:
http://www.epona.ch/german
Animalia:
http://www.haustier-versicherung.ch/
When I looked into insurance I quickly saw that it made no financial sense for us, given the age restrictions and exclusions for pre-existing conditions. The premiums turned out to be more expensive than the yearly vet costs for all but one of my dogs, and that dog was not insurable at all.
For young healthy animals it might be worth your while, though - you'll need to look into each policy carefully, given your individual situation.
FYI, I've found that routine vet care here is actually quite a bargain compared to what I've paid in the US. For years my vet bills here in Switzerland, even for some not-so-routine stuff, were minimal.
Specialist care can be very costly though, as it everywhere. One should be prepared for the unexpected. I've had a pretty awful year with four of my guys - at present I'm spending a small fortune every month. But as it turns out, insurance would not have covered three of the dogs in any case, and the fourth would have exhausted the maximum pay-out within the first set of diagnostic tests. So, I'm still better off paying the vet directly.
But your situation may be entirely different - speak to an advisor.