1. I use the Flower of Life DNA label in the files section, which gives you a circle that you can use to tape the nails down. Then you can get multiple nails in that circle - I use paper tape to attach the nails to the paper. I'm thinking that if you do them in 3 treatments, the cats might reinfect each other while waiting for "their" treatment. If it were me, I'd do a spectrum sweep with the fleas, and the cats all together at the same time, if possible.
2. Typically, we recommend having each taped down to the paper individually so there is at least the thickness of a piece of tape separating each piece of DNA. Yes, all on one piece of paper - can do front and back as applicable.
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