Gary Willoughby is the executive director of the Aiken Society for the Prevention of Cruelty to Animals.

1. What vaccinations should pet owners get for their dog or cat?

In dogs, rabies and distemper, hepatitis, parvo, parainfluenza, coronavirus are core vaccines and are recommended for every dog. The rabies vaccine is required by law. The bordetella vaccine for kennel cough is recommended for all dogs that will be in a boarding or grooming setting or have contact with other dogs.

In cats, rabies, which is required by law, and feline distemper, calicivirus, panleukopenia are core vaccines and are recommended in every cat. The feline leukemia vaccine is recommended for cats that are at risk of contracting the virus, such as cats that go outdoors.

2. Why are vaccinations so important?

Vaccines help prevent diseases in puppies and adult dogs such as distemper, parvo virus infection, hepatitis, parainfluenza and leptospirosis. These vaccines are sometimes known as the five- or six-in-one vaccines, because one vaccine covers the dog for all of these diseases.

3. Why do pets have to get shots each year?

Each animal's potential for exposure to infectious diseases is different. Therefore, the vet will decide case by case the best plan for vaccinating a pet. In general, adult dogs and cats do not require vaccines as often as a pup or kitten. Until recently, the standard of care was to administer all vaccines on an annual basis.

But because of recent studies, it has been shown that some vaccines last much longer than one year in adult animals. Generally, vaccines are administered at least once every three years.

4. What are some of the side effects of vaccinations?

The vaccines given to a pet are very safe. However, in rare instances they can cause a reaction. These reactions can vary from mild to severe and potentially fatal. Small-breed dogs are more likely to have a bad reaction than a large-breed dog. Since reactions to vaccines are not common, the risk of exposure to the illnesses the shots are designed to protect against far outweigh the slight risk of a serious reaction.

5. When should puppies and kittens get their first set of shots?

When they are 6 to 8 weeks old.