Do Older Dogs Need to Be Vaccinated for Parvovirus?

Canine Parvovirus is a virus that attacks the intestinal tract in dogs. Usually the dogs that are most susceptible to Parvo are very young puppies. However, older dogs can get Parvo if they have not been properly protected from it. As the dog ages the chances of becoming ill with Parvo decrease greatly and the level of severity also goes down significantly. For this reason many pet owners are of the opinion that once their dog reaches a specific age, Parvo vaccines are unnecessary. There are a couple of different schools of thought on this issue. There are even some pet owners that do not believe in vaccinating their dogs at all but that is a whole different topic. The problem with Parvo virus in puppies is that it is a very aggressive illness that causes severe diarrhea. This can cause the puppy to become dehydrated very quickly and that is usually the underlying cause of death. Before discussing whether or not older dogs should be vaccinated it is important to understand a little bit about the disease and which dogs are most prone.

Puppies and Parvo Shots

There are a number of things your veterinarian will want to vaccinate your puppy against. Depending on the area you live in there may be specific requirements. For the sake of this article let us look at a typical vaccination schedule for puppies. When your puppy is about 6 to 8 weeks old he will need his very first set of puppy shots. These will be the DHLPP (Distemper, Hepatitis, Leptospirosis, Parvovirus and Parainfluenza) in addition to the Corona shot. Your puppy will need to return to the vet twice more for the same shots; once between 9 and 11 weeks and then again sometime between 12 and 14 weeks. During the last visit your puppy will also be immunized against Rabies. After these initial shots are completed then the suggested return for boosters in once per year. There are a few other vaccinations that your vet could recommend if your dog will be exposed to other dogs on a regular basis and these are Giardia, Kennel Cough (Bordatella) and Lyme Disease.

Why Are Puppies Targeted Most by Parvovirus?

When puppies are born they do get a certain amount of immunity from a variety of illnesses from drinking their mother’s milk. The colostrums contained in their mother’s milk will also contain a lot of the anti-bodies for illnesses she has been exposed to, been sick with or even ones that she has already been vaccinated for. The trouble is there is a window of time in which the puppies are all but nude in terms of protection. This is because it takes a specific amount of time for the anti-bodies from their mother’s milk to kick in and start protecting them. This is the same for human babies and this is why many pediatricians recommend keeping a newborn away from large groups of people in the first month or so. Puppies do not have strong immune systems so the smallest illness can become life threatening very quickly. In actuality, the reason Parvo is so much worse in puppies is because they do not have what they need to help fight the virus off.

Some Breeds Are More Prone to Parvo Than Others

While baffling to veterinarians, there are actually some breeds that tend to be more prone to catching the Parvovirus. Some of these breeds do actually get sick even after being vaccinated. No one is really sure what causes this to happen but the breeds that are most susceptible to Parvo are black and tan breeds such as Doberman Pinschers, Rottweilers. In addition, there has been some indication that American Bulldogs are more apt to get sick with Parvo than other breeds in the bulldog family. If you own one of these breeds then you will want to discuss these things with your vet and make sure that your pet is kept up to date. You will also want to take other steps to protect your dog. If you already know that you have a breed that has been known to become ill with Parvo even when vaccinated properly then you will want to keep your dog away from puppies. This means that even if you handle puppies somewhere else you will want to make sure to wash and disinfect your hands, shoes and clothing before coming in contact with your dog. Bleach is the most effective thing when it comes to killing the Parvo virus on surfaces.

What About My Old Dog?

Now we can get into the original question. An older or senior dog has almost a zero percent chance of ever getting sick with Parvo. Why is this? There are many reasons but the number one reason is that your dog, by the time he is 3 or 4 years old has probably already built up some very good anti-bodies to the Parvovirus, either through vaccines or through other exposure. In addition, as mentioned earlier, on the off chance your older dog does get sick with Parvo it will probably only result in a couple of bouts of minor diarrhea. It is almost unheard of to hear of an older dog dying from Parvo unless there was some other underlying medical condition that cause his immune system to become compromised. Does this mean you should not keep your dog’s vaccination current? Not necessarily. It will be up to you and to your vet as to whether or not you want to continue getting your dog vaccinated into his golden years. However, since the chance is so small of serious illness from Parvo in older dogs, the choice is really yours.

Parvovirus is a very serious and often fatal disease in dogs. However, it can easily be prevented. The best way to protect your dog from becoming ill with this virus is to have him vaccinated for at least the first 4 to 5 years of his life. If you opt to discontinue booster shots at this point then the truth is your dog will probably be fine. Again, always clear everything with a qualified medical professional before making an important decision about your pet.


  1. Grateful to you for sharing your knowledge.

  2. Thanks for the information. I have had 5 cocker spaniels. Two of which died from an autoimmune disease prevalent in the breed. I have always been in favor of yearly boosters until learning that too frequent vaccines actual isn't necessary and can cause autoimmune disease.

  3. Great article. I may be getting a Chihuahua who is being rehomed from a lady. It is a female Chihuahua 5.5 lbs., who is 3-4 years old. She is UTD on her rabies vaccination, but nothing else and needs to be spayed. I found this article very helpful in trying to determine costs!

  4. Thank you for the clear explanations and assured tone of the parvo article. You were refreshingly upbeat and matter of fact, and I really appreciate it for a topic that can be so scary. Thanks for your writing and your time.

Leave a Reply

Your email address will not be published. Required fields are marked *

Recommended Articles