Verkkononcore vaccines are those recommended for some dogs based on lifestyle, geographic location, and risk of exposure. Verkkocore vaccines for dogs are those that protect against canine distemper virus (cdv), canine adenovirus (cav) and the variants of canine. Verkkoa puppy or kitten can only receive a single vaccination (e. g. In the case of cost constraints), vaccination should be with the core vaccines at 16+ weeks of age.