Vaccinations have long been the reason to bring a dog to the veterinarian once a year. However, these yearly visits for vaccinations may not be as necessary as they once were. This may confuse you if your vet still recommends yearly boosters. To make this determination you must look at what vaccinations are, how they work, and which ones your dog needs.
What Vaccinations Do
When you give a vaccination, whether to a puppy or a human baby, you are presenting some form of a specific virus to the body's immune system. A competent immune system, thus challenged, makes antibodies against the virus. The antibodies fight to neutralize the virus, protecting the recipient against the disease.
Any of three types of vaccines might be used. Killed vaccines are exactly what the name suggests: dead viruses. They store well, and they cannot cause disease when administered. But because they are combined with adjuvants — materials to make them more effective in creating an immune response — they are the form most often associated with adverse reactions to the injection.
Modified live viruses are the actual live viruses, changed to make them less virulent. But in an animal with a weakened immune system, this form of vaccine can cause the disease. Recombinant vaccines are the newest form, currently available for rabies, distemper, and Lyme disease. They rely on gene splicing, presenting a portion of the virus or bacteria DNA to the animal. They can't cause the disease and also seem to be causing fewer reactions to vaccinations.
Which Vaccines to Give, and How Often
It was once common to deliver a whopping combination vaccine — DHLPP or some variation (standing for distemper, hepatitis, leptospirosis, parvovirus, and parainfluenza). Most veterinarians now give vaccines for fewer diseases, and they may separate the vaccines into individual injections.
The core vaccines, those essential for all dogs, are now agreed to be rabies, distemper, hepatitis (also called adenovirus 2), and parvovirus. All are serious viral diseases, potentially fatal and highly contagious. Rabies can be transmitted to humans and is invariably fatal once signs of disease occur; therefore, vaccination is regulated by state government. Some states require annual rabies vaccinations, but most mandate vaccinations every three years.
Other vaccines that might be offered to your dog include bordetella (kennel cough), Lyme disease, leptospirosis, parainfluenza, and giardia. Some boarding kennels require a bordetella vaccination because kennel cough is highly contagious among dogs housed closely together. Those with sporting dogs competing in field trials in the Northeast may choose a Lyme vaccine because the disease is common there. Those who go hiking and let their dogs drink from natural water sources may consider a giardia vaccine because the disease-causing organism is common in streams and lakes everywhere. Leptospirosis vaccines are known to cause frequent and extreme reactions in toy dogs, and these should not be given to Yorkshire terriers. If your veterinarian recommends anything beyond these core vaccines, ask why.
Advice on how often to give vaccinations has changed in recent years. Puppies still require a series of shots. They shouldn't be given too early, or the immunity received via nursing will interfere with creation of antibodies. But you also don't want to wait too long and risk exposing your pup to disease. In general, puppies should receive their first immunization at six weeks of age, their second three weeks later at nine weeks, and their third after another three weeks at twelve weeks. The rabies shot is given at sixteen weeks of age. A booster is given at one year of age.
Some dogs have adverse reactions to vaccinations. Signs might include a lump at the vaccination site, generalized hives, swelling on the face and muzzle, lethargy, and anaphylactic shock. Careful veterinarians keep dogs in the office for a half-hour after the injection — most reactions occur in that time.
Once dogs have had their series of puppy shots and the one-year booster, vaccinations can then be renewed every three years. Some advise that all vaccinations should be stopped once dogs pass ten years of age, but this remains controversial, especially for toy breeds, with their generally longer life spans. Many Yorkshire terrier aficionados recommend that vaccinations be separated for these tiny pups. Each shot would only cover one disease, and shots for the three core diseases other than rabies could either be given the same day, but separately, or separated by a few days. This results in quite a few injections, making the veterinary visits rather unpleasant. You want to consider the pluses and minuses before committing to this course of action.