How do vaccinations work?

Vaccinations work by stimulating the immune system and improving the animal's natural defenses. Upon vaccination, sensitized cells are produced in the body. These cells are of various types and are antibodies against the casue of the disease. These antibodies ehlp the body fight the disease.

Why are yearly vaccinations necessary?

The immunity provided by the vaccination is not permanent. Over time the level of immunity decreases. Boosters produce the antibodies necessary for the body to maintain it's defenses. If the immunity is allowed to drop below the protective level, the animal becomes susceptible to disease.

What is the difference between modified live and killed vaccine?

Modified live vaccines multiply in the pet's body and cause the immune system to become stimulated. Killed vaccines don't multiply within the pet; they contain an adjuvant to stimulate the immune response.

Are modified live vaccines safe to use in pregnant animals?

Modified live vaccines used during pregnancy may result in fetal malformation or death.  Infertility and abortion may occur in the mother. However, killed vaccines may be used safely.