They will have a thorough examination, a laboratory test for parasites, and their first vaccines will be given. Dogs should be at least twenty-four months of age. Cats should be at least twelve months of age. They should be at least six months of age. A cat can be persistently infected with FeLV and not show any outward signs of the disease.
Vaccination is the only way to prevent the disease.
Young animals have protective antibodies in their blood given to them by their mother's milk. These antibodies can remain in their bloodstreams up to sixteen weeks of age. These antibodies interfere with vaccinations, and the vaccines will be deactivated. The antibody levels are different in each individual. They can disappear as early as six weeks of age or as late as sixteen weeks of age.