Vaccines contain viruses, bacteria or other disease-causing organisms that have been killed or altered so that they can no longer cause disease. Newer vaccines may contain genetically engineered components derived from those disease agents. When given to an animal, vaccines will stimulate the body's immune system to form disease fighting cells and proteins (known as antibodies) to protect against the disease. Although the protection afforded by vaccines can be reduced by poor health and poor nutrition, most vaccinated animals will be resistant to the disease for which they are fully vaccinated.
How are Vaccines Given?
Most vaccines are given by injection, either under the skin or into the muscle. Some vaccines may be administered as drops into the nostril.
Are Vaccines Safe?
Although vaccines are considered very safe, they can still cause reactions in a small number of pets. Most commonly, cats will feel tired, may run a fever for 24 to 48 hours after vaccination, and may not eat. In some cats, a small, non-painful lump may form at the site where the vaccine was injected; usually disappearing 4 weeks later. Rarely, a cat will develop facial swelling or a severe allergic reaction (anaphylaxis), accompanied by vomiting, diarrhea, breathing difficulties and collapse. Intense facial itchiness may also occur. Anaphylactic reactions are rarely fatal if treated immediately and appropriately.
Are there alternatives to Vaccination?
There are no alternatives to vaccination. Despite the occasional risks associated with vaccination, it is universally accepted that vaccination plays an important role in protecting pets. However, some owners may be disinclined to have their pet vaccinated frequently. For some repeat vaccines, blood samples can measure antibody titers. Though these may not always provide solid evidence of immunity, some clinicians use them as an indicator, along with low risk, that vaccines may be administered at a longer than annual revaccination interval. At this time, not all laboratories are standardized to allow accurate interpretation of results, nor can immunity to all diseases be tested this way. Community health does require vaccination as a strategy to control disease outbreak.
Core Vaccines for Cats
Feline Panleukopenia (parvovirus, distemper)
Panleukopenia is a potentially fatal viral disease that causes vomiting, diarrhea, severe dehydration, fever, and sudden death. Kittens born to infected queens may suffer permanent brain damage. Younger cats appear more susceptible to parvovirus. This disease is easily prevented through vaccination—vaccination is considered highly effective.
Feline Rhinotracheitis (Herpes virus Type 1) and Calicivirus
These organisms infect the airways of cats, causing runny eyes and nose, sneezing, mouth ulcers and sometimes poor appetite. Although vaccines may not prevent infection altogether, they often greatly reduce the severity of the disease. Spread is usually by cat-to-cat contact, aerosols from sneezing cats and infected surfaces. High risk kittens may be vaccinated early for these agents, and all cats should receive the vaccinations for these infections. Mild clinical signs may be noted post-vaccination.
All mammals, including humans, are at risk of contracting rabies, which is almost invariably fatal. Rabid pets may display a "dumb" form which is characterized by listlessness, weakness and paralysis, or the "furious" form of rabies characterized by abnormal aggression. Newer vaccines have safe formulations, and are specially designed for felines. Even indoor cats should receive this vaccine as they can sneak out, and wildlife may unexpectedly enter the home.