With friends and foes of childhood vaccines duking it out in medical journal pages, pet owners may start to wonder: Is the rabies shot safe for my tabby? Does my puppy really need inoculation against lyme disease? Does my ferret? Gerbil? Fact is, though vaccination carries a small risk of adverse reaction, it is recommended -- and some shots are

legally required -- for many pets. Here's how to get the protection they'll need while minimizing

the hazards.

1Get the rabies shot

This one is really not up to you: Proof of rabies vaccination is a must to get a dog or cat license across the Washington area. Penalties for not complying can be hefty; in Montgomery County, it's a $500 fine. The good news: The shot usually runs just $15 to $25, and discounted options are plentiful. The D.C. Animal Shelter ($3, D.C. residents only), the Animal Welfare League of Arlington ($7) and Montgomery County (free for residents, $4 for non-residents) all provide them; check with your local animal shelter for details. Vets usually allow you to choose whether you want your pet to receive the one- or three-year vaccine, so check your local laws -- if they require a vaccination every year, it wouldn't make sense to get your pup the longer-lasting one. Most important: Keep those records! If Fido bites someone and you have no proof that his rabies shot is up-to-date, he could be looking at a death sentence.

2And distemper, too

The law doesn't speak quite so loudly about this vaccine, but it's strongly recommended for dogs, cats -- and ferrets. The last, says David Crum, associate veterinarian at Stahl Exotic Animal Veterinary Services in Vienna, need their own specifically formulated shot because canine distemper is "100 percent fatal" for them. Cats and dogs get what's actually a cocktail of vaccines, each important for the prevention of one horrible illness or another -- including Parvo, a highly contagious, potentially deadly disease for which treatment can run into the thousands of dollars. A distemper shot costs about the same as a rabies shot -- roughly $15 to $25 when administered by your vet. Low-cost clinics don't always offer distemper vaccines, so be sure to ask before you go.

3Know what else is necessary -- or not

An indoor cat probably doesn't need the feline leukemia vaccine, and a dog that lives in the city probably won't confront lyme disease. To make sure you're getting your pet only the appropriate shots, discuss lifestyle in detail with your vet. Keep future plans in mind:

If you're thinking of boarding your dog, the Bordetella vaccine, administered nasally, will protect him from kennel cough. As for small rodents and reptiles,

Crum says they don't need vaccines at all.

4Watch for

adverse reactions

Recent research indicates that a tiny percentage of cats may develop tumors at injection sites -- a condition called post-vaccination sarcoma -- so feel around the area monthly to check for lumps. Other canine and feline allergic reactions may include fever, vomiting, pale gums, hives or diarrhea, usually less than 30 minutes after the vaccination, according to Karen Michaelsen, manager of the Capitol Hill Veterinary Clinic. Ferrets are especially prone: Get their rabies shot at least a week before the distemper one. That way, if there is a reaction, your vet will know which vaccine caused it.

5Opt out if you

have to

In extraordinary circumstances -- if your pet has a dangerously weakened immune system because of cancer or another illness, for example -- your vet may be able to get her exempt from vaccines by requesting in writing that the local government accept a titer (a blood test that measures immunity) instead.

Emily Messner

Need some pet info? Drop a line to pets@washpost.com. Include your name, city and phone number.

"Hey, doc, watch those hands! And remember, I get a special treat after this."