Hello and thank to all for your help!
Unfortunately, until the last case vet didn't do any test. In all cases the treated an animal for 14 days with high temperature for month and a few days. I didn't like the method of this treatment and that's why I'm changed to another vet. In the Czech Republic, he's well known and very well evaluated. Sadly he flight to Africa so on his recommendation i went to another vet, where I am doing viral test by now.
Thanks you once again!