Puppies are 'temporarily' protected against many diseases by antibodies received through their mother's milk. These maternal antibodies decline in the first few months of their lives, however until they drop sufficiently, they can also neutralise vaccines. This is why a series of vaccinations is necessary in a puppy. The recommended age to start vaccinations is six weeks old.
Canine parvovirus is a disease that affects dogs of all ages but is most serious in young pups and older dogs. The virus attacks the intestines causing blood-stained diarrhoea, uncontrollable vomiting and severe abdominal pain. Dogs often die from severe dehydration despite intensive veterinary care.