Dr. Matt Mickas, of Washington State University's College of Veterinary Medicine, answers this week's question.

Question: If a cat remains indoors all the time, do they need the full slate of vaccinations or are there some we can safely omit?

Answer: This is a common concern. If people would like to see our entire recommendations for vaccines they can go to: www.vetmed.wsu.edu/depts-vth/vaccinations.aspx

If a cat is truly an indoor cat, there are only two of the three recommended vaccines we tell clients they need.

The first is a combination vaccine that goes by the acronym, FVRCP, which stands for feline viral rhinotracheitis, calicivirus and panleukopenia.

We use an intranasal form of the vaccine, given to kittens at 8, 12 and 16 weeks of age. It should be repeated annually thereafter. There are injectable vaccines for the same diseases that are considered to last three years.

The second vaccine veterinarians universally recommend is for prevention of rabies. It is given at 12 to 16 weeks of age and repeated annually.

Question: Why do indoor cats need these vaccines?

Answer: We give these for two reasons: The diseases they prevent are devastating, if not fatal, and because we have very good vaccines that prevent those diseases.

For example, rhinotracheitis is a severe upper-respiratory infection caused by a feline type 1, herpesvirus. It is most severe in young kittens and older cats and is one of the most serious upper-respiratory diseases seen in cats. The virus is airborne and very contagious in susceptible animals.

Cats can suffer from several strains of caliciviruses. They cause a range of diseases, from a mild, almost-asymptomatic infection, to life-threatening pneumonia. Most cases show only evidence of problems in the mouth, nasal passages and mucus membranes of the eyes.

The viruses are transmitted by direct contact with an infected cat or object (bowl, cage, brush, blanket, etc.) that harbors the virus. The virus can survive eight to 10 days in the environment. Carrier cats can pass the virus into the environment for up to a year.

Panleukopenia is a highly contagious disease that occurs quickly and has a high mortality rate. It is caused by a parvovirus similar to the parvovirus seen in dogs. It is very resistant and may remain infectious in the environment for up to a year. Infected cats usually require intensive treatment such as IV fluids, antibiotics and supportive care. Mortality rates may run from 50 percent to 90 percent. The vaccine is very effective in preventing the disease.

Finally, rabies is caused by a virus that can infect all mammals, including people. The source of rabies in wildlife in Washington has been limited to the big brown bat, but there is no reason to believe other bats could not be infected.

In general, if a bat is healthy, no human should be able to touch it. If you can, and do touch a bat, you run the risk of being exposed to rabies, which requires an extensive and expensive course of care to prevent this (essentially 100 percent) fatal disease from developing.

Bats, like all wildlife, fall under the control of their state's game agency and most provide important precautions about handling all wild animals, especially bats.

The reason an indoor cat needs to be protected from rabies is essentially twofold: one is because bats and small mammals can and do make their way into homes and cats are very adept at catching them. The second is it would be remiss if a veterinarian did not administer this vaccine because it is potentially a deadly human health problem if your cat becomes rabid by any route.

Dr. Matt Mickas
Mickas is head of the Community Practice Service at Washington State University's College of Veterinary Medicine.

Read our past Q&As:
Veterinary QA follow-up: More on lumps and bumps
Veterinary QA: Should you dress your pet?
Veterinary Q&A: Lumps and bumps
Veterinary Q&A: Puppy and geriatric exams
Veterinary QA: What dogs can safely chew
Veterinary QA: Why does it cost so much to clean a dog's teeth?
Veterinary QA follow-up: More on cleaning a dog's teeth
Veterinary QA: When to spay or neuter

Do you have a question about pet health? Ask now! We'll pose some of your questions to a local vet in an upcoming post.