Before the days of effective vaccines, dogs routinely fell victim to a grim menu of diseases. These included distemper, hepatitis, leptospirosis, parvovirus and complications from upper respiratory diseases.

Today, vaccinations (also called immunization or “shots”) save millions of dogs. Current vaccination programs protect our dogs (and us) from the threat of rabies. Newer vaccines, including those administered through the nostrils, have been developed to protect against a variety of infections.

Are Vaccinations Necessary?

Without doubt, routine vaccinations are essential to prevent infectious diseases in puppies. However, despite the well-known benefits of vaccination, the practice of annual vaccination of mature dogs is controversial. Some veterinarians believe that annual revaccination is an important and critical part of preventative health care. Others suggest that there is little scientific information to suggest that annual revaccination of older dogs is necessary for some diseases. Immunity to many viruses may last for the life of the animal. However, there has been insufficient research conducted in this area of long-term protection. Of course, some vaccines (rabies) are required by law and must be administered on a regular basis.

Puppies receive immunity against infectious disease in their mother’s milk; however, this protection begins to disappear between 6 and 20 weeks of age. The exact sequence cannot be predicted without specialized blood tests. To protect puppies during this critical time, a well-researched approach is taken: a series of vaccines is given every 3 to 4 weeks until the chance of contracting an infectious disease is very low.

The typical vaccine is a “combination” that protects against canine distemper virus, canine adenovirus, parainfluenza and canine parvovirus (the four viruses are commonly abbreviated DHPP). Many veterinarians also recommend incorporating leptospirosis in the vaccination series. Rabies vaccines are given between 16 and 26 weeks of age in most states (governed by law). All vaccines require booster immunizations (“shots”) that are given one year later. Thereafter, the issue becomes cloudier.

The protective effect of vaccinations for bacterial infections (e.g. bordetella and leptospirosis) typically do not persist for more than a year making yearly (and occasionally more frequent) booster vaccines advisable. If your adult dog has an adverse reaction to the vaccine (fever, vomiting, shaking, facial swelling or hives) discuss the risk of annual revaccination with your veterinarian.

Recommendations

The foremost recommendation is to discuss the vaccination program with your veterinarian. Don’t be hesitant to ask questions about the pros and cons of vaccinations.

Puppies 4 to 20 weeks of age: In puppies, a series of vaccines is recommended. These should begin between 6 and 8 weeks of age. Typically the last vaccination is given between 14 and 16 weeks of age. The vaccine should protect against canine distemper virus, canine adenovirus, parainfluenza and canine parvovirus. If the risk of kennel cough is great, a vaccine against bordetella is recommended. Rabies vaccine should be given in accordance with individual state laws usually between 16 and 26 weeks of age. Newer vaccines effective against specific forms of the bacteria leptospirosis may be important in some areas.

Dogs 20 weeks to 2 years: It is important to booster the puppy vaccines in young adult dogs to ensure adequate lifelong immunity against deadly viral diseases. Your veterinarian will likely “booster” your dog one year after the “puppy” vaccine series to protect against canine distemper virus, canine adenovirus, parainfluenza and canine parvovirus. If the risk of kennel cough is great, a vaccine against bordetella is recommended. The rabies vaccines should be given as recommended by local law. Newer vaccines effective against specific forms of the bacteria leptospirosis may be important in some areas.

Dogs older than 2 years: Annual revaccination (boosters) is recommended for the first year after the “puppy vaccines”; thereafter, you should discuss the benefits and risks of annual vaccination with your vet. In the past, the DHLP (distemper, hepatitis, leptospirosis, parvovirus) vaccine was typically given each year. These recommendations may be changing. Specific vaccine requirements for individual dogs should be discussed with your veterinarian. The most appropriate vaccination program for your pet should be followed.

Again, if the risk of kennel cough is great, a vaccine against bordetella is recommended. The bordetella vaccine needs to be given at least yearly, and each year you and your veterinarian should assess whether it is required. The rabies vaccine should be given as recommended by local law. Newer vaccines effective against specific forms of the bacteria leptospirosis may be important in some areas. The need for the vaccine should be determined based on the area of the country your dog lives in and his or her life-style. If given, they should be administered once to twice a year.

There is currently a vaccination available for canine influenza virus. The benefits of this vaccine are similar to the benefits of other “flu” vaccines – including human vaccines. The vaccine is intended to help control virus infection and spread. The vaccine may not totally prevent infection in all dogs. What it will do is reduce the severity of disease, reduce the duration of clinical illness, and reduce lung damage. The vaccine has also been shown to reduce the amounts of virus shed and the duration of virus shedding.

Vaccinated dogs develop less severe illness and are less likely to spread the virus to other dogs. The vaccine is recommended for dogs “at risk”. Dogs that frequently interact with other dogs, participate in activities with other dogs or are boarded are considered at risk and can benefit from vaccination. Dogs that benefit from the kennel cough vaccine (Bordetella/parainfluenza) vaccine will also benefit from the canine influenza vaccine.

Other vaccinations that are sometimes given by your veterinarian include coronavirus, Lyme and giardia. These are not routinely given to every animal, and their use should be discussed with your veterinarian.