Dear Dr. Stillman,
I just got a puppy and want to take him walking around town. One of my friends says that it’s not safe to do that yet. What’s the story?
Congratulations on your new pup. That’s very exciting.
Your friend is right about your pup’s vulnerability. Let me explain. When a puppy is born she has no natural immunity at all. During her first day or two of life an amazing process takes place. The puppy’s mother makes a very unusual type of milk for the first day or two of lactation. This special milk, called colostrum, contains proteins called antibodies, which the body uses to fight foreign invaders and infections. The puppy has the ability to absorb these proteins, or antibodies, whole from the colostrum without digesting them. In other words, antibodies from the pup’s mother are transferred directly into the pup’s bloodstream in their intact and active form. There they are able to protect the pup from disease in the same way they protected her mother. Astounding!
Unfortunately, these antibodies do not last forever. They begin to wear off almost as soon as the pup acquires them, but the rate at which they wear off is unpredictable. Some pups lose this “maternal immunity” very quickly, and other pups will manage to hold onto it almost until their 16-week birthday. We have no way to know which pup will lose it quickly and which one slowly, so for the safety of the pups we assume that they all lose it quickly. In other words, it’s safest to assume that every pup has lost most of the immunity that her mother gave her at birth by the time you get her from the shelter or the breeder.
For that reason it’s best to protect your pup from situations where she might be exposed to diseases that she’s susceptible to until her own immune system is fully functional and able to protect her all by itself. We usually say that the age where a pup’s immune system is fully functional is 16 weeks. Up until then we try not to take her places where strange dogs go or let her interact with strange dogs. They might be carrying diseases that could harm her.
Sometimes someone will ask me if it’s enough that they not let their pup sniff the poop of other dogs. The answer is no. Long after poop has eroded or washed away the disease-causing organisms may still be present on the ground where it was deposited. It’s better to just stay away from the risk altogether.
You can, however, take her to your friend’s house if she has a dog whom you know is vaccinated. You can also take her to your friend’s house if she has no dog at all. After 16 weeks of age her immune system will be up and running, she’ll be fully vaccinated by your vet, and you can take her anywhere you want.
Page 2 of 2 - Dr. Norm Stillman is a veterinarian at the Court Street Animal Hospital, located at 136 Court St. in Plymouth, Mass. He can be reached by phone at 508-747-0774 or by email at email@example.com.