PRO PLAN PUPPY OPTISTART IMMUNITY GAP

Whilst still suckling, puppies receive antibodies from their mothers' milk that give them a certain level of immunity.

Once weaned, their antibody levels drop, leaving a gap in their protection while their own immune systems develop. Immunity in puppies remains low until 5 months*, meaning that, by the time your puppy comes to live with you, he is in the "immunity gap".

* Reference: Ishikawa H, Tabuchi H and Ohashi E (1998) Changes in the serum immunoglobulin concentrations in puppies. J Vet Med Japan 51: 801-805).