Kathy McNulty, age 11, of Trumbull, Conn., for her question:

HOW DOES A DOG CONTACT DISTEMPER?

Distemper is a contagious disease of young dogs. It usually starts with a loss of appetite, chill, fever, redness of the eyes and dry muzzle. Later there may be infection in the lungs, intestines or nervous system.

Distemper is caused by a virus discovered by Louis Carre of France in 1904.

A puppy's distemper can be prevented by vaccination with specially prepared vaccines. It can be treated by giving the dog antiserum and other drugs. The dog should definitely be under the care of a veterinarian.

Dogs that have recovered from one attack of distemper are immune to later attacks.

Distemper of young horses is called strangles. It is caused by bacteria and differs from distemper in dogs. It is treated with antibiotics such as penicillin.