What do newborn puppies receive from their mother that provides initial immune protection?

• A. None
• B. A complete immune system
• C. Bacteria to colonize the gut
• D. A supply of antibodies

Answer: (D)

Newborn puppies rely on maternal antibodies because their own immune systems are not yet ready to fight infections. The mother’s first milk, colostrum, is packed with immunoglobulins. When a puppy nurses, these antibodies are absorbed into the bloodstream and provide immediate, temporary protection against pathogens. This passive transfer is most effective in the first hours after birth, giving the puppy a protective shield until its own immune system matures and vaccines begin to take effect. So the best description of what boosts their early immunity is a supply of antibodies from the mother. The other ideas don’t fit this protective mechanism: a full immune system isn’t present at birth, and while gut bacteria will begin to establish after birth, they don’t provide the kind of direct antibody-based protection Colostrum delivers.