How Often Should My Dog Receive Vaccinations?

What Vaccinations Should He Get?

Ron Hines DVM PhD 1/8/04

Vaccinations Given In The United States:
For the last forty years, it has been standard veterinary practice in the United States to vaccinate dogs yearly for canine distemper virus (CDV), canine leptospirosis (CL), canine adenovirus-1 & hepatitis (CAV-1), canine parainfluenza virus (CPIV), canine parvovirus (CPV), canine Coronavirus (CV) as well as canine bordatella or kennel cough and Lyme disease.

How Vaccines Work:

Vaccines stimulate the immune system to produce antibodies to a disease organism so that the dog is protected against various pathogens in its environment. If the immunized dog is later exposed to the infectious agent, these antibodies react quickly to attack and neutralize the disease

Puppyhood Vaccinations:

When it comes to puppies most veterinarians are in agreement. Puppies should receive their CDV,CL, CAV-1,CPIV and CPV vaccinations at 7-9 weeks of age, 12-13 weeks of age, and finally at 16-18 weeks of age to insure they are well protected against these diseases. I generally administer an intranasal preparation of canine bordatella at 12 and 18 weeks of age. At 12-16 weeks of age I give puppies a killed three-year rated rabies virus vaccination (Meriel Emrab-3).

All the products on the market for canine leptospirosis are all killed products. Those for the rest of these diseases are freeze-dried living virus that have been grown in tissue culture in a way that makes them non-pathogenic i.e. unable to cause disease. Actually, a single injection, at the right time, of all these live products imparts good, long lasting immunity to all of these diseases. The problem is that puppies absorb antibodies against these diseases from their mothers.

Depending on the level of immunity in the mother, this transient parental immunity in the offspring interferes with the puppy’s ability to produce its own long lasting immunity to these diseases. In some puppies, parental immunity is low enough that by 8-12 weeks the vaccination to work. In others, parental immunity interferes with the action of the vaccine for up to 18 weeks. The tests that determine parental immunity levels in puppies are expensive and rarely run. So because we do not know just when to vaccinate we give a series of three or four injections so that at least one of them will work. I only give Coronavirus vaccine to puppies because it is a disease of puppies.

Adult Immunizations:

Once we are sure we have a protected puppy we need to decide how often we should revaccinate the pet to keep immunity levels protective. Until recently, veterinarians simply gave all dogs booster shots every year. This is what the vaccine manufacturers suggested. Besides, it brought our clientele back to our animal hospitals yearly, which increased our income and gave us the opportunity to detect problems early before the owners were aware of them. Most veterinarians do a thorough physical examination on pets at the time of their yearly vaccinations and we often detect problems during the exam.. By law, most states require a yearly rabies vaccination even though studies have shown that many of the rabies vaccines we use give us three years of protection.

Many veterinarians, myself included, were suspicious that the vaccines we used were giving much longer periods of protection than one year. We knew this because we never saw distemper, hepatitis or parvovirus disease in dogs that had been vaccinated - even many years earlier. Part of the problem involves the typical fee structures of veterinary practices. We tend to undercharge for complex surgery and subsidize those procedures with the money we earn on yearly vaccinations.

I do not know how this practice came about but it has existed at least since the 1950’s. There was also an incentive for vaccine manufacturers to sell more vaccine if boosters were recommended annually as well as a one-year mindset among the bureaucrats that staff the USDA Center for Veterinary Biologics that dictate vaccination protocols. These are the same deep thinkers that put a two-year expiration date on a vial of water.

How Frequently To Immunize:

In the January 2004 issue of a U.S. veterinary journal, an article was published by the Pfizer Drug Company, a major manufacturer of dog vaccines. They determined that their canine vaccines were active (protective) up to and beyond four years after administration for all five of these diseases (1). Other studies have documented immunity lasting up to seven years (2)(3). No two vaccine manufactures produce identical products so you should not assume that the brand your veterinarian uses induces this long immunity but I suspect they all protect well over a year.

There may be risks associated with too frequent vaccinations. For one, the immune system of your pet is stressed by these vaccinations. Occasional dogs develop allergic reactions, facial edema, enteritis, lethargy, fevers, pruritis, nausea, coughing. We also suspect that vaccinations can trigger certain autoimmune diseases such as Adison’s disease on dogs. Occasionally these reactions are life threatening. Vaccines contain many ingredients besides the dried virus.

Some of these, antibiotics and adjuvants (enhancers) are implicated in vaccine reactions. When these vaccinations are given they are best given subcutaneously with a TB syringe with 25-gauge needle. This small needle is less likely to carry a plug of skin into the injection site causing swelling and inflammation. In dogs that have had prior history of vaccine reactions I often do not give yearly vaccinations.

I feel the risks outweigh the benefits. If I am suspicious that a dog might have a reaction to a particular vaccine I pre-administer antihistamines (Benadryl) and give a minute test dose of 0.05ml. If the dog is normal thirty minutes after the test dose I give it the remaining one-milliliter. I limit yearly or every two-year vaccinations for the four “core” diseases to “higher risk dogs”.

Higher risk dogs are dogs that roam or take unsupervised strolls; dogs that play with other dogs not from their household, dogs that have contact with wild animals, or swim and drink from pools puddles and streams. Other higher risk dogs are coprophagic (eat stool). Others are more at risk because the attend obedience classes, dog shows, field trials, and large grooming and boarding facilities. About half the dogs I see fall into this higher risk category.

Determining The Need For Booster Vaccinations By Serum Titer:

The scientific way to determine if your dog needs a booster vaccination is to run serum titer tests. Protective titres for CDV are 1:32 or greater. For CAV-1, CAV-2 and CPIV titer of 1:16 or greater are protective and for CPV titer of 1:80 or greater are protective and mean your dog does not need a booster vaccination. Many veterinary laboratories already offer this service http://www.antechdiagnostics.com/ .

Least protective appear to be the vaccinations against CPIV, Bordatella, Lime Disease and the various serovars (types) of Leptospirosis. For these diseases, annual vaccination is probably a good idea. It is a good idea to give your pet a booster vaccination against Bordatella (kennel cough) about two weeks before it is kenneled.

1) Mouzin DE, Lorenzen, MJ, Haworth JD, King VL, Duration of serologic response to five viral antigens in dogs. JAVMA; 224(1) January 1, 2004, 55-60

2) Coyne MJ, Burr JHH, Yule TD, et. al. Duration of immunity in dogs after vaccination or naturally acquired infection. Vet Rec 2001;149:509-515.

3) Schultz RD. Current and future canine and feline vaccination programs. Vet Med 1998; 93:233- 254..