Switzerland doesn't have a dedicated pet-pharmacy chain in the way Italy has parafarmacie. Instead, regular human pharmacies (Apotheke in German, pharmacie in French, farmacia in Italian) and the slightly less regulated Drogerie drugstores both commonly stock basic pet items: flea and tick treatments, wound care, and some supplements.
Anything prescription-only — antibiotics, stronger pain relief, specific parasite treatments requiring a prescription — still needs a vet visit, same as anywhere in Europe. Given Switzerland's dense network of vet clinics, this is rarely a major delay.
Given the country's high price level, it's worth bringing a reasonable supply of any specific product you rely on regularly, rather than assuming it'll be cheaper or easier to simply restock locally.