Dear Christopher Cat: I thought I would save money by sharing my shih tzu's flea medicine with my cat. I applied only one drop to my cat and put the remainder of the vial on my dog.

Within minutes, my cat started to drool and tremble, and on the way to the animal hospital, seizures began. Tragically, the veterinarian could not save my cat's life.

He said the dog flea product contained an ingredient that's toxic to cats. Please warn your readers so they don't have to go through the agony my cat and I suffered.

Christopher responds: I am very sorry for your loss. Your courage in writing will surely save the lives of other cats.

Many topical insecticide products for dogs contain pyrethroids, neurotoxins that paralyze and kill fleas and ticks. Pyrethroids are synthetic versions of pyrethrins, natural insecticides derived from chrysanthemums.

Permethrin is a popular pyrethroid. Many other pyrethroid names end in "thrin."

Unfortunately, cats are exquisitely sensitive to permethrin and other pyrethroids, so these chemicals must never be applied to them.

Mom doesn't even use them on the dogs in our family, because if we cats rub up against them or snuggle with them shortly after they're treated, we could be poisoned.

Toxic signs include tremors, seizures, loss of coordination, excitability, weakness, drooling, vomiting, diarrhea and loss of appetite.

I hope our readers heed your warning to examine labels and use products only on the intended species.

Dear Daisy Dog: I bought a 10-week-old boxer puppy, Midas, this week. The breeder gave him a distemper-parvo vaccination and told me to make an appointment with a veterinarian. Do I really need to do that, since he's already been vaccinated? If so, when?

Daisy responds: All dogs, regardless of age, need multiple distemper-parvo vaccinations in the initial series. In addition, puppies require a rabies vaccination between 12 and 16 weeks of age.

Depending on Midas' lifestyle, your veterinarian may recommend additional vaccines, such as Lyme, leptospirosis and kennel cough.

What's even more important, though, is your veterinarian's physical exam and recommendations about maintaining good overall health, controlling parasites and preventing behavior problems.

Here in Pennsylvania, the Dog Purchaser Protection Act, sometimes called the puppy lemon law, covers you as long as your new dog is examined by a veterinarian within 10 days of purchase. If your vet finds a problem, you can be compensated.

So it's important that you and Midas start today to develop a lifelong relationship with a veterinarian you both like.

Ask the Vet's Pets appears Friday in the print edition of the Reading Eagle. The animal authors of the column live with Lee Pickett, V.M.D., who practices companion animal medicine at Bernville Veterinary Clinic. Contact them at www.askthevetspets.com, 610-488-0166 or P.O. Box 302, Bernville, PA 19506-0302.