PARVO is deadly. So difficult. The sweet pups that did not ask to suffer like this struggle as their intestinal lining basically sloughs out and their bone marrow is reduced to a shambles leaving them incredibly immune suppressed and susceptible to sepsis.
Likewise DISTEMPER. How deeply sad it is to look at that febrile pup with mucus everywhere and know that they would likely die no matter what treatment is initiated.
RABIES is zoonotic and completely fatal, and amazingly woven into our local wildlife. Transmission may not always be obvious if say a bat gets into the home and is consumed by the pet as it struggles. This scenario is very possible.
Vaccines for these diseases are a gift. Life saving.
How do we balance the necessary and critical protection for our friends against harm from overzealous vaccination? Are there harms in vaccination? Where is the line between enough and too much?
First we will discuss the minimum requirements of essential vaccination. We will then discuss the not so obvious but very real consequences of overzealous vaccination and attempt to help you determine what is right for your dog, for each situation is a bit different and you are the guardian of your pet. In subsequent posts we will discuss noncore or non essential vaccines although some of these are being reconsidered as core vaccination and require careful thought for your situation.
For puppies these vaccinations offer critical protection, especially Parvo and Distemper which are given as a combination vaccine.
The unknown is when they are effective. For some puppies, from say a puppy mill situation or from very well vaccinated mothers there was a significant transfer of antibodies from the mother in the milk through nursing. This immunity will naturally then last much longer than in the puppy from a situation where the mother was not vaccinated or poorly vaccinated and had little to give her pups. The issue is that the maternal antibodies, or antibodies provided by the mother, will bind up the antigens from the vaccine rendering it useless. Now the puppy has no antibodies from the mother and no antibody response of its own because the vaccine was bound up. This leaves the puppy really vulnerable, but we don’t know when. For this reason puppies get a series of parvo and distemper vaccines that must go past 16 and ideally out to 18 weeks to be sure they have immunity they themselves have generated.
If a puppy was born to a mother with a poor or unknown vaccine history it is wise to start them a bit younger, say 8 weeks. A puppy born to a very well vaccinated mother could wait until 12 weeks because the vaccine won’t be effective anyway. There are some vaccines designed specifically to address this problem and work despite high maternal antibodies. Regardless, this vaccine should be repeated between 16 and 18 weeks of age because the immune system needs to see these antigens twice to generate a really good response.
The general recommendation is to boost this vaccine again one year later and then every three years.
Two thoughts: It is possible that the two puppy vaccines can give life long immunity measured through “titers” or antibody levels in the body. It is optimal to give that booster at one year to really cement this immunity but I have patients with strong positive titers one decade out from their puppy boosters never having received another vaccine. However, boosting at 12 months makes sense.
Secondly, although most Distemper Parvo vaccines for adults are labelled as a three year duration of immunity the actual studies on Duration of Immunity for most of these preparations are 4 years. And so it is perfectly acceptable to wait four years from that 1 year booster to give this vaccine again. It is really doubtful that any further boosters would be beneficial or confer any greater immunity.
For decades veterinarians were giving this vaccine every year to every dog. Was this harmful?
What if we give this vaccine with another one or even two other vaccines?
Vaccine hypersensitivity reactions occur right away, within minutes. That might look like intense itching or facial swelling. Sometimes, frighteningly, there can be anaphylaxis and difficulty breathing that requires immediate intervention with antihistamines and cortisone medication for survival. Fortunately this isn’t common but it can occur with the odds of this going up when more vaccinations are administered together.
The most common vaccine reaction is fever and myalgia (muscle soreness), perhaps with lethargy (feeling lousy) and vomiting a few hours after vaccination for a day or two. This generally passes on its own in time. This is the direct effect of the vaccine causing cytokine production (inflammation) and starting the immune response cascade.
Further out from vaccination and not immediately obvious, is a period of immunosuppression where a subclinical infection might emerge or an unknown already brewing neoplasia can take root and start to grow. The vaccine did not cause these illnesses, but the immune suppression or the refocusing of the immune system on these new threats allowed them to occur. Look for this 4 to 8 weeks after the annual healthy visit with vaccination. From the American Society of Microbiology in an article on Understanding Immunological Memory, we find this statement: “Repeated exposure through vaccines can cause exhaustion of the immune system and may induce the immune system to become less responsive or even suppress certain related immune functions altogether” (1).
Sometimes there is an opposite or rebounding effect of vaccination on the immune system and instead of immune suppression there is immune mediated thrombocytopenia or immune mediated hemolytic anemia (2). Suddenly the immune system is attacking the body’s own platelets or red blood cells. Issues occur with clotting or with severe anemia again often 4 to 8 weeks after vaccination. A complete blood count that shows really low platelet counts or anemia at this stage should not be disregarded.
Is there a relationship with atopy or environmental allergies causing severe long term itching? It would make sense that a highly sensitized immune system starts reacting against pollens, molds, and anything else it sees in the environment. Often allergy flareups can be traced to a healthy annual visit 6 to 8 weeks before in which the patient received multiple vaccinations, an immune system fry visit. This is not proven but it makes sense. Fully one third of our patients are now seen for atopy or severe abnormal itching in response to environmental pollens.
What about rabies vaccination? This is given generally at 4 to 6 months of age, boosted one year later, then every three years. There is little room for error with this as it is a deadly and zoonotic disease and the risk is real.
This is the only vaccine that does not require a booster four weeks later on initial vaccination. It has to work and work really well given once.
This is a strong vaccine. Respect it and give it by itself at least four and ideally 8 to 12 weeks apart from any other vaccination.
You are the guardian of your dog. Consider the pup in your lap vulnerable and give those Distemper Parvo boosters 4 weeks apart, ideally at 12 weeks and at 16 to 18 weeks. If the puppy is at higher risk from an unvaccinated mother or exposed to other puppies, then start earlier at 8 weeks but really try not to give more than three boosters total.
Wait two months after that last Distemper Parvo booster and give the Rabies vaccine later, at 6 months of age. The following year when these vaccines come due again try to give the Distemper Parvo vaccine if anything slightly early, say 11 months later, so that the subsequent Rabies booster can be given three months later. From that point know that the Distemper Parvo vaccine just given now has a documented Duration of Immunity of four years, and so you can separate it from subsequent Rabies boosters by a full year or elect to have titer tests done instead so that there is proof that the Distemper and Parvo is still there. There is not that room to adjust with the Rabies vaccine.
This will not be a program that your veterinarian suggests to you. You will need to keep track of this yourself and safely advocate for your friend to give them what is needed for protection while also protecting the fragile and yet powerful immune system that keeps him safe. Respect vaccinations as a medical procedure that is never routine.
- Shittu. A Understanding Immunological Memory (Am. Soc for Microbiology; 5/11/23)
2. Day, Shultz Immunology; Principles and Practice (2014; CRC Press; Boca Raton FL)
