Immunity Challenge

Are vaccines safe for my dog?

The type and number of vaccinations our dogs receive are a common topic of discussion among breeders, owners and veterinarians. Those opposed to vaccines are just as passionate about their views as those who are in favor. Both sides have valid points. Immunization is important to maintain healthy dogs, but vaccination reactions can be scary and even life-threatening.

Vaccines were developed to help prevent infectious disease. Since the first vaccines were made, the technology has advanced tremendously. Over the years, veterinarians have seen fewer vaccine-related issues than previously reported. Vaccine opponents often argue that ingredients such as adjuvants such as mercury, aluminum, formaldehyde and foreign proteins are often the source of reactions to the vaccines.

While this was true in the past, many vaccines have been “purified” over the years, meaning the additives have been removed. Some of the adjuvants have been entirely discontinued in the production of vaccines. This has made them much less reactive for our dogs.

The risk of adverse reactions to vaccination can occur in many species, but the rate of these reactions is low. The risk of not having immunity to common infectious diseases far outweighs the risk of developing a serious illness as a result of a vaccination.

What if my dog has had a vaccine reaction?

Vaccine reactions can be as mild as a slight swelling or lump in the area. Each vaccine has a designated location for injection on the body, so if a localized reaction occurs in that spot, it is easy to know which vaccine caused it. More severe vaccine reactions are swelling of the face and eyes and hives — anywhere from a few to all over the body. The most serious reactions can result in anaphylactic shock, which is a sudden, life-threatening response by the immune system. This can be so severe that the dog collapses, has trouble breathing and may suffer cardiac arrest.

There are some steps you can take to minimize the chance of a vaccine reaction while still making sure your dog is protected. Evaluate your dog’s lifestyle to determine which vaccines are essential and which are not needed. A rabies vaccination every three years is required by law in most places.

Avoid giving multiple vaccines at the same time. Separate vaccine administration by at least three weeks if an adverse reaction was previously seen when multiple vaccines were given on the same day.

Pre-medicate with an injection or oral dose of diphenhydramine (Benadryl) and possibly a dose of a corticosteroid before giving the vaccinations. Some dogs will not react when a different brand of vaccine is given for the next scheduled booster.

Allow longer intervals between core vaccines, such as distemper and parvo, after the initial puppy series is completed. Many practices offer three-year vaccines for protection against these viruses.

How is a titer different from a vaccination?

Vaccine titers have been gaining more acceptance in the past few years to reduce the frequency of vaccination. Titers are checked by obtaining a blood sample and submitting it for testing.

A titer is a measure of the concentration of antibodies in the blood. Antibodies are immunoglobulins, which are highly specialized protein molecules that bind to foreign substances called antigens and neutralize them.

The antibody level is obtained using a test involving repeatedly diluting a blood sample and exposing those dilutions to an antigen. All measurements of the antibody concentration are referred to as titers.

Two criteria need to be met to determine if the titer is valid. The first is the detection of a measurable amount of antibody (immunity) to a disease in the blood sample. The second is the need for challenge studies performed to ensure protection with a specific titer level. A challenge study shows that dogs that have a specified antibody titer did not get sick when exposed to the disease for which the titer was checked.

Titers can be useful to determine the need for canine distemper and parvovirus boosters. These are core vaccines. All dogs should receive core vaccines due to the widespread prevalence and severity of the diseases that they prevent.

After the dog has completed its initial series of these vaccines and boosters one year later, annual titers can be run to evaluate the need for continued boosters. Many dogs have immunity to these diseases that lasts for many years. Both the AVMA and AAHA recommend increasing the vaccine interval for canine distemper and parvo from one year to three years based on titer-testing results.

Vaccine titers will also detect dogs that have lower immunity and need a booster vaccine. Titer testing can also be done at the end of the initial series of vaccinations to ensure the patient mounted a protective immune response to the vaccine.

Can my dog get a rabies titer instead of the vaccination?

The titer testing for rabies is a different situation. Rabies is a potentially fatal disease that can be transmitted to humans. Rabies vaccination is required by law in most states as part of rabies control and prevention policies. These laws currently do not include the use of titers in place of vaccination.

The other complicating factor is that there is no agreed standard titer value that is considered protective. Not all laboratories that determine titers are accredited, and not all testing methods are accurate. For a disease that is vitally important to public health, it is advised to use a lab that is accredited and has quality-control measures in place. The Rabies Laboratory of Kansas State University is the recommended laboratory for rabies titer testing.

The most common reason for rabies titer testing is to verify rabies-antibody status for dogs that are traveling to destinations that require proof of vaccination. There is usually a protocol whereby the dog must be vaccinated and then have a blood sample drawn at a specified time, in most cases four to six weeks post-vaccine. Some destinations even require a second titer, so advance planning may be necessary. The laboratory performs the blood test for verification that the vaccine was given and the dog has immunity to the rabies virus.

In addition to titer testing, the laboratory also tests the brain tissue of deceased animals suspected of being infected with the rabies virus. The three tests used to measure rabies antibodies are the Fluorescent Antibody Virus Neutralization (FAVN) test, the Rapid Fluorescent Focus Inhibition Test (RFFIT) and the Enzyme-linked Immunosorbent Assay (ELISA).